LOL AT THIS

--SATFINDER PORTABLE Version 1.3 - Español

-- Ready to be used with LuaPlayerHM6.5

--Satfinder has been created by:
--Pedro J. Fernández - [email protected]
--Guillermo Fernández - [email protected]

--Special thanks to:
--Razorblade - [email protected]
--Dr. T.S.Kelso - [email protected]
--John Walker (Home Planet) - http://www.fourmilab.ch/
--John A. Magliacane (Predict) - http://www.qsl.net/kd2db/

function screen.height()
    return 272
end
function screen.width()
    return 480
end

function SF_initialize()
    -- Inicialiamos algunos colores
    sf_color_white = color.new(255,255,255)
    sf_color_black = color.new(0,0,0)
    sf_color_red = color.new (255,0,0)
    sf_palette = {}
    sf_star_palette = {}
    sf_palette_len = 16

    sf_color_day = {}
    sf_color_night = {}


    sf_color_day.r = 0
    sf_color_day.g = 255
    sf_color_day.b = 0

    sf_color_night.r = 255
    sf_color_night.g = 0
    sf_color_night.b = 0

    SF_changePalette (sf_color_day.r,sf_color_day.g,sf_color_day.b)
    SF_crearPaletaEstrellas()

    sf_selected_sat = 0

    -- Borramos las dos pantallas (doble buffer)
    screen.clear(sf_color_black)
    screen.waitvblankstart()
    screen.flip()
    screen.clear(sf_color_black)
    screen.waitvblankstart()
    screen.flip()


    local file = io.open("update.txt")

    local mensaje
    if file then
        local line = file:read("*l")
        local update_jt = tonumber(line)
        if update_jt ~= nil then
            local ct = os.date("*t")

            -- This functions only works in LuaPlayerHM6.5
            ct.year = tonumber(os.date("%Y"))
            ct.month = tonumber(os.date("%m") )
            ct.day = tonumber(os.date("%d"))
            ct.hour = tonumber(os.date("%I"))
            if string.lower(os.date("%p")) == "pm" then
                ct.hour = ct.hour + 12.0
            end
            ct.min = tonumber(os.date("%M"))
            ct.sec = tonumber(os.date("%S"))


            -- current_time.year , month, day, hour, min, sec, isdst
            local jt = SGP_Date_To_Julian(ct.year, ct.month, ct.day, ct.hour, ct.min, ct.sec)
            local diff = jt - update_jt
            local dias_julianos = diff

            screen.print(440, 261, "v1.3", sf_palette[4])
            screen.waitvblankstart()
            screen.flip()
            screen.print(440, 261, "v1.3", sf_palette[4])
            screen.waitvblankstart()
            screen.flip()


            screen.print(1, 1, "> Comprobando edad de los ficheros TLE: "..string.format("%.2f",dias_julianos).." dias" , sf_palette[4])
            screen.waitvblankstart()
            screen.flip()
            screen.print(1, 1, "> Comprobando edad de los ficheros TLE: "..string.format("%.2f",dias_julianos).." dias" , sf_palette[4])
            screen.waitvblankstart()
            screen.flip()

            if dias_julianos > 3 then
                screen.print(1, 11, "  Los arhivos TLE son demasiado viejos!" , sf_color_red)
                screen.print(1, 21, "  Actualiza con SatFinder Updater o via WIFI." , sf_color_red)
                screen.waitvblankstart()
                screen.flip()
                screen.print(1, 11, "  Los arhivos TLE son demasiado viejos!" , sf_color_red)
                screen.print(1, 21, "  Actualiza con SatFinder Updater o via WIFI." , sf_color_red)
                screen.waitvblankstart()
                screen.flip()

            else
                screen.print(1, 11, "  Los arhivos TLE son suficientemente recientes.", sf_palette[1])
                screen.print(1, 21, "  No es necesario actualizar." , sf_palette[1])
                screen.waitvblankstart()
                screen.flip()
                screen.print(1, 11, "  Los arhivos TLE son suficientemente recientes.", sf_palette[1])
                screen.print(1, 21, "  No es necesario actualizar." , sf_palette[1])
                screen.waitvblankstart()
                screen.flip()
            end
        end
    end



    screen.print(1, 31, "> Comprobando asistente de voz... " , sf_palette[4])
    screen.waitvblankstart()
    screen.flip()
    screen.print(1, 31, "> Comprobando asistente de voz... " , sf_palette[4])
    screen.waitvblankstart()
    screen.flip()

    --System.oaenable();
    local sound_welcome = sound.load("SatFinder/welcome.wav",false)
    sound_welcome:play()
    screen.waitvblankstart(5)
    while sound_welcome:playing() do
        screen.waitvblankstart(5)
    end

    screen.print(274, 31, "OK!" , sf_palette[1])
    screen.waitvblankstart()
    screen.flip()
    screen.print(274, 31, "OK!" , sf_palette[1])
    screen.waitvblankstart()
    screen.flip()

    screen.print(1, 41, "> Definiendo constantes... " , sf_palette[4])
    screen.waitvblankstart()
    screen.flip()
    screen.print(1, 41, "> Definiendo constantes... " , sf_palette[4])
    screen.waitvblankstart()
    screen.flip()

    -- Constantes
    SF_constants()
    SGP_initCoefficients()

    screen.print(216, 41, "OK!" , sf_palette[1])
    screen.waitvblankstart()
    screen.flip()
    screen.print(216, 41, "OK!" , sf_palette[1])
    screen.waitvblankstart()
    screen.flip()


    screen.print(1, 51, "> Definiendo variables... " , sf_palette[4])
    screen.waitvblankstart()
    screen.flip()
    screen.print(1, 51, "> Definiendo variables... " , sf_palette[4])
    screen.waitvblankstart()
    screen.flip()

    -- Sky configuration
    sf_sky_color = color.new(0,0,0)
    sf_sky = {}
    sf_sky.radio = 241
    sf_sky.centro = {}
    sf_sky.centro.x = 241
    sf_sky.centro.y = 137
    sf_sky.elevacion_minima = 0
    sf_sky.color = sf_color_black
    sf_sky.orientacion = -1.0
    sf_sky.rotacion = 0.0
    sf_sky.show = {}
    sf_sky.show.satellites = true
    sf_sky.show.satelliteNames = false
    sf_sky.show.stars = true
    sf_sky.show.autoMagStars = false
    sf_sky.show.constellationNames = false
    sf_sky.show.sunAndMoon = true
    sf_sky.show.elevationLines = true

    sf_next_visible_results = {}

    sgp_sun = {}
    sgp_sun.raise = {}
    sgp_sun.set = {}

    sgp_location = {}
    sgp_location.polar = {}
    sgp_location.day = {}
    sgp_location.night = {}

    sgp_moon = {}
    sgp_moon.age = {}
    sgp_moon.raise = {}
    sgp_moon.set = {}
    local i


    sf_pass_max = 23
    sf_pass_limit = 0
    sf_pass_current = 0
    sf_passes = {}
    for i = 1,sf_pass_max do
        sf_passes[i] = {}
    end

    sf_pass_path = {}
    sf_pass_path.longitud = 0
    sf_pass_path.max = 256

    for i = 1,sf_pass_path.max do
        sf_pass_path[i] = {}
    end

    sf_primera_busqueda = true
    sf_next_visible_show_info = false
    sf_next_visible_precision = 0.4


    sf_primer_calculo = true

    sf_vision_nocturna = true

    sf_moving_sky = false
    sf_zoom_mode = false

    sf_moon_wait = 0
    sf_sun_wait = 0

    -- Carga de imagenes en memoria
    bitmap_sol = image.load("SatFinder/sol.png")
    bitmap_cruz = image.load("SatFinder/cruz.png")
    bitmap_luna = image.load("SatFinder/luna_dia.png")



    screen.print(208, 51, "OK!" , sf_palette[1])
    screen.waitvblankstart()
    screen.flip()
    screen.print(208, 51, "OK!" , sf_palette[1])
    screen.waitvblankstart()
    screen.flip()


    screen.print(1, 61, "> Cargando configuracion... " , sf_palette[4])
    screen.waitvblankstart()
    screen.flip()
    screen.print(1, 61, "> Cargando configuracion... " , sf_palette[4])
    screen.waitvblankstart()
    screen.flip()

    if SF_loadConfigFromFile("config.txt") then
        screen.print(216, 61, "OK!" , sf_palette[1])
        screen.waitvblankstart()
        screen.flip()
        screen.print(216, 61, "OK!" , sf_palette[1])
        screen.waitvblankstart()
        screen.flip()
    else
        screen.print(216, 61, "Usando valores por defecto." , sf_color_red)
        screen.waitvblankstart()
        screen.flip()
        screen.print(216, 61, "Usando valores por defecto." , sf_color_red)
        screen.waitvblankstart()
        screen.flip()
    end


    screen.print(1, 71, "> Cargando satelites... " , sf_palette[4])
    screen.waitvblankstart()
    screen.flip()
    screen.print(1, 71, "> Cargando satelites... " , sf_palette[4])
    screen.waitvblankstart()
    screen.flip()


    -- Satelites
    sgp_sats = { }
    sgp_sat_number = 0 -- esta variable tiene que ser cero y se modifica por SGP_getTLE()

    SGP_getTLE("./tle/visual.tle")
    SGP_getTLE("./tle/iridium.tle")




    if sgp_sat_number == -1 then
        screen.print(192, 71, "Error: Archivos TLE corruptos." , sf_color_red)
        screen.waitvblankstart()
        screen.flip()
        screen.print(192, 71, "Error: Archivos TLE corruptos." , sf_color_red)
        screen.waitvblankstart()
        screen.flip()
        sgp_sat_number = 0
    elseif sgp_sat_number == -2 then
        screen.print(192, 71, "Error: Faltan archivos TLE." , sf_color_red)
        screen.waitvblankstart()
        screen.flip()
        screen.print(192, 71, "Error: Faltan archivos TLE." , sf_color_red)
        screen.waitvblankstart()
        screen.flip()
        sgp_sat_number = 0
    else
        screen.print(192, 71, "OK! (".. sgp_sat_number..")" , sf_palette[1])
        screen.waitvblankstart()
        screen.flip()
        screen.print(192, 71, "OK! (".. sgp_sat_number..")" , sf_palette[1])
        screen.waitvblankstart()
        screen.flip()
    end

    sf_next_max = sgp_sat_number
    sf_next_limit = 0
    sf_next_current = 0
    sf_next_passes = {}
    for i = 1,sf_next_max do
        sf_next_passes[i] = {}
    end

    screen.print(1, 81, "> Cargando estrellas... " , sf_palette[4])
    screen.waitvblankstart()
    screen.flip()
    screen.print(1, 81, "> Cargando estrellas... " , sf_palette[4])
    screen.waitvblankstart()
    screen.flip()

    sgp_mag_limit = 3.4
    sgp_mag_max = 4.2
    sf_star_update_rate_limit = 10
    sf_star_update_current_rate = 1
    sgp_star_number = 0
    sgp_constellation_number = 0

    SGP_getStars("allstars.txt", sgp_mag_max)



    screen.print(192, 81, "OK! (" .. sgp_star_number ..")", sf_palette[1])
    screen.waitvblankstart()
    screen.flip()
    screen.print(192, 81, "OK! (" .. sgp_star_number ..")", sf_palette[1])
    screen.waitvblankstart()
    screen.flip()

    screen.print(1, 91, "> Cargando informacion del observador... " , sf_palette[4])
    screen.waitvblankstart()
    screen.flip()
    screen.print(1, 91, "> Cargando informacion del observador... " , sf_palette[4])
    screen.waitvblankstart()
    screen.flip()


    -- Localizacion de observacion
    if not SGP_getLocationFromFile("location.txt") then
        SGP_setLocation(39.232, -6.536, 80, 1, "Defecto", false)
        screen.print(322, 91, "Usando informacion por defecto." , sf_color_red)
        screen.waitvblankstart()
        screen.flip()
        screen.print(322, 91, "Usando informacion por defecto." , sf_color_red)
        screen.waitvblankstart()
        screen.flip()
    else
        screen.print(322, 91, "OK!" , sf_palette[1])
        screen.waitvblankstart()
        screen.flip()
        screen.print(322, 91, "OK!" , sf_palette[1])
        screen.waitvblankstart()
        screen.flip()

    end

    screen.print(1, 101, "> Calculando posicion de los satelites... " , sf_palette[4])
    screen.waitvblankstart()
    screen.flip()
    screen.print(1, 101, "> Calculando posicion de los satelites... " , sf_palette[4])
    screen.waitvblankstart()
    screen.flip()

end

function SF_clacularOtrosDatos()
    screen.print(330, 101, "OK!" , sf_palette[1])
    screen.waitvblankstart()
    screen.flip()
    screen.print(330, 101, "OK!" , sf_palette[1])
    screen.waitvblankstart()
    screen.flip()

    screen.print(1, 111, "> Calculando fases lunares... " , sf_palette[4])
    screen.waitvblankstart()
    screen.flip()
    screen.print(1, 111, "> Calculando fases lunares... " , sf_palette[4])
    screen.waitvblankstart()
    screen.flip()

    SGP_calculateMoonPhases ()

    screen.print(234, 111, "OK!" , sf_palette[1])
    screen.waitvblankstart()
    screen.flip()
    screen.print(234, 111, "OK!" , sf_palette[1])
    screen.waitvblankstart()
    screen.flip()

    screen.print(1, 121, "> Calculando amaneceres y ocasos... " , sf_palette[4])
    screen.waitvblankstart()
    screen.flip()
    screen.print(1, 121, "> Calculando amaneceres y ocasos... " , sf_palette[4])
    screen.waitvblankstart()
    screen.flip()

    SGP_calculateSunRaiseTime()
    SGP_calculateSunSetTime()
    SGP_calculateNightBegining()
    SGP_calculateNightEnding()
    SGP_calculateMoonRaiseTime()
    SGP_calculateMoonSetTime()

    screen.print(282, 121, "OK!" , sf_palette[1])
    screen.waitvblankstart()
    screen.flip()
    screen.print(282, 121, "OK!" , sf_palette[1])
    screen.waitvblankstart()
    screen.flip()

    screen.print(1, 131, "> Procesando estrellas, espere... " , sf_palette[4])
    screen.waitvblankstart()
    screen.flip()
    screen.print(1, 131, "> Procesando estrellas, espere... " , sf_palette[4])
    screen.waitvblankstart()
    screen.flip()

end

function SGP_getCurrentTime()
    if not sf_primer_calculo then
        sgp_last_time = sgp_time
    end

    sgp_time = os.date("*t")

    -- This functions only works in LuaPlayerHM6.5
    sgp_time.year = System.getDate(1)
    sgp_time.month = System.getDate(2)
    sgp_time.day = System.getDate(3)
    sgp_time.hour = System.getTime(1)
    if System.getTime(5) == "pm" then
        sgp_time.hour = sgp_time.hour + 12.0
    end
    sgp_time.min = System.getTime(2)
    sgp_time.sec = System.getTime(3)
    sgp_time.isdst = sgp_location.dst
    sgp_time.jtime = SGP_Date_To_Julian(sgp_time.year, sgp_time.month, sgp_time.day, sgp_time.hour, sgp_time.min, sgp_time.sec)
    sgp_time.ujtime = SGP_Local_to_UTC(sgp_time.jtime)
    sgp_time.uyear,sgp_time.umonth,sgp_time.uday,sgp_time.uhour,sgp_time.umin,sgp_time.usec = SGP_Julian_To_Date(sgp_time.ujtime)

    if sf_primer_calculo then
        sgp_last_time = sgp_time
    end
end


function SF_drawTextMap(latitud, longitud, texto, color)
    local px, py = SF_LatLonToXY(latitud, longitud)

    local len = texto:len()

    if latitud > 0 then
        py = py-4 + 8
    else
        py = py-4 - 8
    end
    screen.print(px, py, texto, color)
end

function SF_AzElevToXY( azimut, elevacion )
        local distanciaCentro =   sf_sky.radio * ((90.0-elevacion)/90.0) * (90 / (90-sf_sky.elevacion_minima))

        local x, y

        local azimut_rotated = azimut + sf_sky.rotacion;

        x = sf_sky.radio + (distanciaCentro * math.sin(azimut_rotated*math.pi/180.0) * sf_sky.orientacion)
        y = sf_sky.radio - distanciaCentro * math.cos(azimut_rotated*math.pi/180.0)

        x = x + (sf_sky.centro.x - sf_sky.radio)
        y = y + (sf_sky.centro.y - sf_sky.radio)

        return x , y
end

function SF_drawTextSky(azimut, elevacion, texto, color)
    local txt
    if texto == nil then
        txt = "nil"
    else
        txt = texto
    end
    if elevacion > sf_sky.elevacion_minima then
        local px, py = SF_AzElevToXY( azimut, elevacion )
        local longitud = texto:len()

        screen.print(px-2-((longitud-1)*4), py-2, txt, color)
    end
end

function SF_drawPointSky( azimut , elevacion , color )
    if elevacion > sf_sky.elevacion_minima then
        local px, py = SF_AzElevToXY( azimut, elevacion )
        if px > 0 and px < screen.width()-1 and py > 0 and py < screen.height()-1 then
            image.pixel( px , py , color )
            return true
        end
    end
    return false
end

function SF_LatLonToXY(latitud, longitud)
  local x, y
  y = math.floor(latitud * 1.51111)
  x = math.floor(longitud * 1.33333)
  x = 240 + x
  y = 136 - y
  return x, y
end

function SF_drawPointMap( latitud , longitud , color )
    local px, py = SF_LatLonToXY(latitud, longitud)
    if px > 0 and px < screen.width() and py > 0 and py < screen.height() then
        image.pixel( px , py , color )
    end
end

function SF_drawCircleSky(radio,azimut,elevacion,color)
    local px, py = SF_AzElevToXY( azimut, elevacion )

    x0 = math.sin(math.pi-0/32*2*math.pi) * radio + px
    y0 = math.cos(math.pi-0/32*2*math.pi) * radio + py


    for i=1,64 do
        x1 = math.sin(math.pi-i/32*2*math.pi) * radio + px
        y1 = math.cos(math.pi-i/32*2*math.pi) * radio + py
        if x1 > 0 and x1 < screen.width() and y1 > 0 and y1 < screen.height() then
            if x0 > 0 and x0 < screen.width() and y0 > 0 and y0 < screen.height() then
                draw.line(x0, y0, x1, y1, color)
            end
        end
        x0 = x1
        y0 = y1
    end
end

function SF_drawElevationLine (elevacion, color)
    local azimut = 0
    if elevacion >= 0 and 90 > elevacion then
        local px, py = SF_AzElevToXY( -sf_sky.rotacion, elevacion )
        SF_drawCircleSky(py - sf_sky.centro.y, 0, 90, color)
    elseif elevacion == 90 then
        SF_drawPointSky(azimut, elevacion, color)
    end
end

function SF_drawLineSky( azimut1 , elevacion1 , azimut2, elevacion2, color )
    if ((elevacion1 > sf_sky.elevacion_minima) and (elevacion2 > sf_sky.elevacion_minima)) then
        local x1, y1 = SF_AzElevToXY( azimut1, elevacion1 )
        local x2, y2 = SF_AzElevToXY( azimut2, elevacion2 )
        if x1 > 0 and x1 < screen.width() and y1 > 0 and y1 < screen.height() then
            if x2 > 0 and x2 < screen.width() and y2 > 0 and y2 < screen.height() then
                draw.line( x1, y1, x2, y2, color)
            end
        end
    end
end

function SF_drawElevation()
    SF_drawElevationLine (0,sf_palette[14])
    SF_drawElevationLine (30,sf_palette[14])
    SF_drawElevationLine (60,sf_palette[14])
    SF_drawElevationLine (90,sf_palette[14])
    --SF_drawText("30", 300 , 26 , sf_palette[8])
    --SF_drawText("60", 300 , 56 , sf_palette[8])
    SF_drawTextSky(300 , 86 , "90", sf_palette[12])
    SF_drawTextSky(120 , 34 , "30", sf_palette[14])
    SF_drawTextSky(120 , 64 , "60", sf_palette[14])
    SF_drawTextSky(120 , 4  , "0" , sf_palette[12])

end

function SF_drawNSEW()
    SF_drawTextSky( 0 , 45 , "N", sf_palette[14])
    SF_drawTextSky( 90 , 45 , "E", sf_palette[14])
    SF_drawTextSky( 180 , 45 , "S", sf_palette[14])
    SF_drawTextSky( 270 , 45 , "W", sf_palette[14])
end

function SF_drawBitmapSky( azimut , elevacion , bitmap, xini, yini, xlen, ylen )
    if elevacion > 0 then
        local px, py = SF_AzElevToXY( azimut, elevacion )
            image.blit(px - xlen/2, py - ylen/2, bitmap, xini, yini, xlen, ylen, true)
    end
end

function SF_dibuarLineasReferencia()

    if sf_r_pressed and not sf_zoom_mode then
        return
    elseif sf_l_pressed then
        SF_drawMap()
    else
        -- Dibujamos los puntos cardinales N, S, E, W (O)
        SF_drawNSEW()

        -- Dibujamos las lineas de elevación con los grados en texto
        if sf_sky.show.elevationLines then
            SF_drawElevation()
        else
            SF_drawElevationLine(0,sf_palette[14])
            SF_drawElevationLine(90,sf_palette[14])
        end
    end
end

function SF_procesarSol(ujtime)
    SF_calcularSol(ujtime) -- Rellena los valores de sgp_sun
    SF_dibujarSol()
end

function SF_calcularSol(ujtime)
    if sf_sun_wait <= 0 then
        SGP_calculateSun (ujtime)
        sf_sun_wait = 20
    else
        sf_sun_wait = sf_sun_wait - 1
    end
end

function SF_dibujarSol()
    --if sf_l_pressed then
    --  screen.print(100,130,"Dibujando mapa",sf_palette[8])
    --end
    if sf_r_pressed and not sf_zoom_mode then
        SF_drawBackgroundInfo()
        SF_drawSunInfo()
    elseif sf_sky.show.sunAndMoon then
        if sf_l_pressed then
            SF_drawBitmapMap(sgp_sun.lat, sgp_sun.lon , bitmap_sol,0,0,bitmap_sol:width(),bitmap_sol:height() )
        elseif sgp_sun.ele > 0 then
                SF_drawBitmapSky(sgp_sun.azi, sgp_sun.ele , bitmap_sol,0,0,bitmap_sol:width(),bitmap_sol:height() )
        end
    end
end



function SF_procesarLuna(ujtime)
    SF_calcularLuna(ujtime) -- Rellena los valores de sgp_moon
    SF_dibujarLuna()
end

function SF_calcularLuna(ujtime)
    if sf_moon_wait <= 0 then
        SGP_calculateMoon (ujtime)
        sf_moon_wait = 200
        local numero_imagen = sgp_moon.age.cicle * 16 - 0.5
        if numero_imagen < 0 then
            numero_imagen = numero_imagen + 16
        end
        numero_imagen = math.floor(numero_imagen)
        sf_moon_x_desp = numero_imagen * 16

    else
        sf_moon_wait = sf_moon_wait - 1
    end
end

function SF_dibujarLuna()
    if sf_sky.show.sunAndMoon then

        if sf_r_pressed and not sf_zoom_mode then
            SF_drawMoonInfo()
            image.blit(218, 172, bitmap_luna, sf_moon_x_desp, 0, 16, 16, true)
        else
            if sf_l_pressed then
                SF_drawBitmapMap(sgp_moon.lat, sgp_moon.lon, bitmap_luna, sf_moon_x_desp, 0, 16, 16)
            else
                if sgp_moon.ele > 0 then
                    SF_drawBitmapSky(sgp_moon.azi, sgp_moon.ele, bitmap_luna, sf_moon_x_desp, 0, 16, 16)
                end
            end
        end
    end
end

function SF_crearPaletaEstrellas()
    for i = 1 , sf_palette_len do
        local nivel = math.floor(255 * (1-((i-1)/sf_palette_len)))
        sf_star_palette[i] = color.new(nivel,nivel,nivel)
    end
end

function SF_cambiarMagnitudAuto()
    local daylight
    if sgp_sun.ele < const_twilightCivil and sgp_sun.ele > const_twilightNautical then
        daylight = (sgp_sun.ele-const_twilightCivil)/(const_twilightNautical-const_twilightCivil)
    elseif sgp_sun.ele >= const_twilightCivil then
        daylight = 0.0
    else
        daylight = 1.0
    end
    sgp_mag_limit = ((sgp_mag_max + 2) * daylight) - 2
end

function SF_procesarEstrellas(ujtime)
    if sf_primer_calculo then
        SF_calcularEstrellas(ujtime)
    elseif sf_sky.show.stars and not sf_l_pressed  then
        if sf_sky.show.autoMagStars then
            SF_cambiarMagnitudAuto()
        end
        if not sf_moving_sky then
            SF_calcularEstrellas(ujtime)
        end
        SF_dibujarEstrellas()
    end
end

function SF_calcularEstrellas(ujtime)
    local star

    if sf_primer_calculo then
        for star = 1,sgp_star_number do
            if sgp_stars[star].no_calcular <= 0 then
                if sgp_stars[star].mag < sgp_mag_max then
                    sgp_stars[star].azi, sgp_stars[star].ele = SGP_RADecToAzElev( ujtime,sgp_stars[star].ra,sgp_stars[star].dec,sgp_location.lat, sgp_location.lon)

                    if sgp_stars[star].ele < 0 then
                        sgp_stars[star].no_calcular = 10 * -sgp_stars[star].ele
                    end
                end
            else
                sgp_stars[star].no_calcular = sgp_stars[star].no_calcular - 1
            end
        end
        cursor_stars = 1
    else
        local stars_to_calc = sf_star_update_current_rate
        while stars_to_calc > 0 and cursor_stars < sgp_star_number   do
            while  ((sgp_stars[cursor_stars].no_calcular > 0) and sgp_stars[cursor_stars].mag < sgp_mag_limit and (cursor_stars < sgp_star_number)) do
                sgp_stars[cursor_stars].no_calcular = sgp_stars[cursor_stars].no_calcular - 1
                cursor_stars = cursor_stars + 1
            end
            if cursor_stars >= sgp_star_number then
                cursor_stars = 1
                if sf_star_update_current_rate + 1 < sf_star_update_rate_limit then
                    sf_star_update_current_rate = sf_star_update_current_rate + 1
                else
                    sf_star_update_current_rate = sf_star_update_rate_limit
                end
            else
                if sgp_stars[cursor_stars].no_calcular <= 0 then
                    if sgp_stars[cursor_stars].mag < sgp_mag_limit then
                        sgp_stars[cursor_stars].azi, sgp_stars[cursor_stars].ele = SGP_RADecToAzElev( ujtime,sgp_stars[cursor_stars].ra,sgp_stars[cursor_stars].dec,sgp_location.lat, sgp_location.lon)
                        stars_to_calc = stars_to_calc - 1
                        if sgp_stars[cursor_stars].ele < 0 then
                            sgp_stars[cursor_stars].no_calcular = 10 * -sgp_stars[cursor_stars].ele
                        end
                    else
                        sgp_stars[cursor_stars].no_calcular = sgp_stars[cursor_stars].no_calcular - 1
                    end
                else
                    sgp_stars[cursor_stars].no_calcular = sgp_stars[cursor_stars].no_calcular - 1
                end
                cursor_stars = cursor_stars + 1
            end

        end
    end
end

function SF_dibujarEstrellas()
    if sf_r_pressed and not sf_zoom_mode then
        SF_drawStarsInfo()
    else
        local star, color
        for star = 1,sgp_star_number do
            if sgp_stars[star].mag < sgp_mag_limit then
                if sgp_stars[star].ele > 0 then
                    color = math.floor((sgp_stars[star].mag - sf_sky.radio/241*0.2 + 1)/4*16 )
                    if color < 1 then
                        color = 1
                    elseif color > 16 then
                        color = 16
                    end
                    if not SF_drawPointSky(sgp_stars[star].azi, sgp_stars[star].ele , sf_star_palette[color]) then
                        sgp_stars[star].no_calcular = 10
                    end
                end
            end
        end
    end
end

function SF_procesarSatelites(ujtime)
    if sf_primer_calculo then
        SF_calcularSatelites(ujtime)
        SF_dibujarSatelites()
    elseif sf_sky.show.satellites then
        if not sf_moving_sky then
            SF_calcularSatelites(ujtime)
        end
        SF_dibujarSatelites()
    end
end

function SF_calcularSatelites(ujtime)
    if sf_primer_calculo then
        --Para cada satélite obtener sus datos para el tiempo actual, incluido el sol
        sf_elevacion_max = 0
        for s = 1,sgp_sat_number do
            --Calcular solo si no está suspendido temporalmente para optimizar recursos
            if sgp_sats[s].no_calcular <= 0 then
                SGP_calculateSatellite (s, ujtime)
                -- Nos vamos quedando con el satélite con elevación más alta
                -- Necesario para los avisos por voz.
                if sgp_sats[s].elevacion > sf_elevacion_max and sgp_sats[s].visible then
                    sf_elevacion_max = sgp_sats[s].elevacion
                    sf_azimut_max = sgp_sats[s].azimut
                end
                --Optimizacion

                if sgp_sats[s].elevacion < sf_sky.elevacion_minima then
                    if sgp_sats[s].elevacion_ant > sgp_sats[s].elevacion then -- bajando por debajo del horizonte
                        sgp_sats[s].no_calcular = math.random (30,60)
                    else -- subiendo por debajo del horizonte
                        sgp_sats[s].no_calcular = math.random (10,30)
                    end

                    if sgp_sats[s].numero == sf_iss then
                        sgp_sats[s].no_calcular = 10
                    end
                end

            else
                --Descontar un calculo suspendido
                sgp_sats[s].no_calcular = sgp_sats[s].no_calcular - 1
            end
        end
        cursor_satelite = 1
    else

        while ((sgp_sats[cursor_satelite].no_calcular > 0) and (cursor_satelite < sgp_sat_number)) do
            sgp_sats[cursor_satelite].no_calcular = sgp_sats[cursor_satelite].no_calcular - 1
            cursor_satelite = cursor_satelite + 1
        end
        if cursor_satelite >= sgp_sat_number then
            cursor_satelite = 1
        else
            SGP_calculateSatellite (cursor_satelite, ujtime)
            -- Nos vamos quedando con el satélite con elevación más alta
            -- Necesario para los avisos por voz.
            if sgp_sats[cursor_satelite].elevacion > sf_elevacion_max and sgp_sats[cursor_satelite].visible then
                sf_elevacion_max = sgp_sats[cursor_satelite].elevacion
                sf_azimut_max = sgp_sats[cursor_satelite].azimut
            end

            --Optimizacion

            if sgp_sats[cursor_satelite].elevacion < sf_sky.elevacion_minima then
                if sgp_sats[cursor_satelite].elevacion_ant > sgp_sats[cursor_satelite].elevacion then -- bajando por debajo del horizonte
                    sgp_sats[cursor_satelite].no_calcular = math.random (30,60)
                else -- subiendo por debajo del horizonte
                    sgp_sats[cursor_satelite].no_calcular = math.random (10,30)
                end
                if sgp_sats[cursor_satelite].numero == sf_iss then
                    sgp_sats[cursor_satelite].no_calcular = 10
                end
            end
            cursor_satelite = cursor_satelite + 1
        end

    end
end


function SF_dibujarSatelites()
    if sf_primer_calculo then
        sf_vision_nocturna = sgp_location.noche

        sf_tail_length = 16
        sf_step_length = 20
        SF_initTails()
    end

    local s
    if sf_r_pressed and not sf_zoom_mode then
        SF_drawSatsInfo()
    elseif sf_l_pressed then
        for s = 1,sgp_sat_number do
            SF_drawSatMap( s )
        end
        SF_drawSatPathMap()
    else
        for s = 1,sgp_sat_number do
            if sgp_sats[s].elevacion > 0  and  sgp_sats[s].elevacion_ant < 0 then
                SF_initTail(s)
            end
            SF_drawSatSky( s )
        end
        SF_drawSatPathSky()
    end

end

function SF_procesarConstelaciones(jt)
    if sf_r_pressed and not sf_zoom_mode then
        return
    end
    if sf_sky.show.constellationNames and not sf_l_pressed then
        if not sf_moving_sky then
            SF_calcularConstelaciones(jt)
        end
        SF_dibujarConstelaciones()
    end
end

function SF_calcularConstelaciones(jt)
    local c
    for c=1,sgp_constellation_number do
        if sgp_constellations[c].no_calcular > 0 then
            sgp_constellations[c].no_calcular = sgp_constellations[c].no_calcular - 1
        else
            sgp_constellations[c].az, sgp_constellations[c].el =  SGP_RADecToAzElev( jt,sgp_constellations[c].label_ra,sgp_constellations[c].label_dec,sgp_location.lat, sgp_location.lon)
            if el < 0 then
                sgp_constellations[c].no_calcular = math.random(50,100)
            end
        end
    end
end

function SF_dibujarConstelaciones()
    local c
    for c=1,sgp_constellation_number do
        if sgp_constellations[c].el > 0 then
            SF_drawTextSky(sgp_constellations[c].az , sgp_constellations[c].el ,sgp_constellations[c].nombre, sf_palette[14])
        end
    end
end

function SGP_Local_to_UTC(jtime)
  local jt = jtime
  jt = jt - sgp_location.UTC_offset/24.0
  if sgp_time.isdst then  --si estamos en horario de verano
    jt = jt - 1.0/24.0
  end
  return jt
end


function SGP_UTC_to_Local(jtime)
  local jt = jtime
  jt = jt + (sgp_location.UTC_offset/24.0)
  if sgp_time.isdst then
    jt = jt + (1.0/24.0)
  end
  return jt
end

function SF_drawLabelSatsSky(azimut, elevacion, texto, color)
    if elevacion > sf_sky.elevacion_minima then
        local px, py = SF_AzElevToXY( azimut, elevacion )
        if azimut > 90 and azimut < 270 then
            sky:print(px+ 5, py-10, texto, color)
        else
            sky:print(px+ 5, py+2, texto, color)
        end
    end
end

function SGP_setLocation(lat, lon, alt, offset, name, dst)
    sgp_location.lat = lat
    sgp_location.lon = lon
    sgp_location.alt = alt
    sgp_location.UTC_offset = offset
    sgp_location.name = name
    sgp_location.dst = dst
    sgp_location.polar.lat = math.rad(sgp_location.lat)
    sgp_location.polar.lon = math.rad(SGP_modulus(sgp_location.lon,360))
    sgp_location.polar.alt = sgp_location.alt * 0.001
end

function SGP_initCoefficients()

    sgp_lrCoeff = {}

    sgp_lrCoeff[1] = {0, 0, 1, 0}
    sgp_lrCoeff[2] = {2, 0,-1, 0}
    sgp_lrCoeff[3] = {2, 0, 0, 0}
    sgp_lrCoeff[4] = {0, 0, 2, 0}
    sgp_lrCoeff[5] = {0, 1, 0, 0}
    sgp_lrCoeff[6] = {0, 0, 0, 2}
    sgp_lrCoeff[7] = {2, 0,-2, 0}
    sgp_lrCoeff[8] = {2,-1,-1, 0}
    sgp_lrCoeff[9] = {2, 0, 1, 0}
    sgp_lrCoeff[10] = {2,-1, 0, 0}
    sgp_lrCoeff[11] = {0, 1,-1, 0}
    sgp_lrCoeff[12] = {1, 0, 0, 0}
    sgp_lrCoeff[13] = {0, 1, 1, 0}
    sgp_lrCoeff[14] = {2, 0, 0,-2}
    sgp_lrCoeff[15] = {0, 0, 1, 2}
    sgp_lrCoeff[16] = {0, 0, 1,-2}
    sgp_lrCoeff[17] = {4, 0,-1, 0}
    sgp_lrCoeff[18] = {0, 0, 3, 0}
    sgp_lrCoeff[19] = {4, 0,-2, 0}
    sgp_lrCoeff[20] = {2, 1,-1, 0}
    sgp_lrCoeff[21] = {2, 1, 0, 0}
    sgp_lrCoeff[22] = {1, 0,-1, 0}
    sgp_lrCoeff[23] = {1, 1, 0, 0}
    sgp_lrCoeff[24] = {2,-1, 1, 0}
    sgp_lrCoeff[25] = {2, 0, 2, 0}
    sgp_lrCoeff[26] = {4, 0, 0, 0}
    sgp_lrCoeff[27] = {2, 0,-3, 0}
    sgp_lrCoeff[28] = {0, 1,-2, 0}
    sgp_lrCoeff[29] = {2, 0,-1, 2}
    sgp_lrCoeff[30] = {2,-1,-2, 0}
    sgp_lrCoeff[31] = {1, 0, 1, 0}
    sgp_lrCoeff[32] = {2,-2, 0, 0}
    sgp_lrCoeff[33] = {0, 1, 2, 0}
    sgp_lrCoeff[34] = {0, 2, 0, 0}
    sgp_lrCoeff[35] = {2,-2,-1, 0}
    sgp_lrCoeff[36] = {2, 0, 1,-2}
    sgp_lrCoeff[37] = {2, 0, 0, 2}
    sgp_lrCoeff[38] = {4,-1,-1, 0}
    sgp_lrCoeff[39] = {0, 0, 2, 2}
    sgp_lrCoeff[40] = {3, 0,-1, 0}
    sgp_lrCoeff[41] = {2, 1, 1, 0}
    sgp_lrCoeff[42] = {4,-1,-2, 0}
    sgp_lrCoeff[43] = {0, 2,-1, 0}
    sgp_lrCoeff[44] = {2, 2,-1, 0}
    sgp_lrCoeff[45] = {2, 1,-2, 0}
    sgp_lrCoeff[46] = {2,-1, 0,-2}
    sgp_lrCoeff[47] = {4, 0, 1, 0}
    sgp_lrCoeff[48] = {0, 0, 4, 0}
    sgp_lrCoeff[49] = {4,-1, 0, 0}
    sgp_lrCoeff[50] = {1, 0,-2, 0}
    sgp_lrCoeff[51] = {2, 1, 0,-2}
    sgp_lrCoeff[52] = {0, 0, 2,-2}
    sgp_lrCoeff[53] = {1, 1, 1, 0}
    sgp_lrCoeff[54] = {3, 0,-2, 0}
    sgp_lrCoeff[55] = {4, 0,-3, 0}
    sgp_lrCoeff[56] = {2,-1, 2, 0}
    sgp_lrCoeff[57] = {0, 2, 1, 0}
    sgp_lrCoeff[58] = {1, 1,-1, 0}
    sgp_lrCoeff[59] = {2, 0, 3, 0}
    sgp_lrCoeff[60] = {2, 0,-1,-2}


    sgp_bCoeff = {}

    sgp_bCoeff[1] = {0, 0, 0, 1}
    sgp_bCoeff[2] = {0, 0, 1, 1}
    sgp_bCoeff[3] = {0, 0, 1,-1}
    sgp_bCoeff[4] = {2, 0, 0,-1}
    sgp_bCoeff[5] = {2, 0,-1, 1}
    sgp_bCoeff[6] = {2, 0,-1,-1}
    sgp_bCoeff[7] = {2, 0, 0, 1}
    sgp_bCoeff[8] = {0, 0, 2, 1}
    sgp_bCoeff[9] = {2, 0, 1,-1}
    sgp_bCoeff[10] = {0, 0, 2,-1}
    sgp_bCoeff[11] = {2,-1, 0,-1}
    sgp_bCoeff[12] = {2, 0,-2,-1}
    sgp_bCoeff[13] = {2, 0, 1, 1}
    sgp_bCoeff[14] = {2, 1, 0,-1}
    sgp_bCoeff[15] = {2,-1,-1, 1}
    sgp_bCoeff[16] = {2,-1, 0, 1}
    sgp_bCoeff[17] = {2,-1,-1,-1}
    sgp_bCoeff[18] = {0, 1,-1,-1}
    sgp_bCoeff[19] = {4, 0,-1,-1}
    sgp_bCoeff[20] = {0, 1, 0, 1}
    sgp_bCoeff[21] = {0, 0, 0, 3}
    sgp_bCoeff[22] = {0, 1,-1, 1}
    sgp_bCoeff[23] = {1, 0, 0, 1}
    sgp_bCoeff[24] = {0, 1, 1, 1}
    sgp_bCoeff[25] = {0, 1, 1,-1}
    sgp_bCoeff[26] = {0, 1, 0,-1}
    sgp_bCoeff[27] = {1, 0, 0,-1}
    sgp_bCoeff[28] = {0, 0, 3, 1}
    sgp_bCoeff[29] = {4, 0, 0,-1}
    sgp_bCoeff[30] = {4, 0,-1, 1}
    sgp_bCoeff[31] = {0, 0, 1,-3}
    sgp_bCoeff[32] = {4, 0,-2, 1}
    sgp_bCoeff[33] = {2, 0, 0,-3}
    sgp_bCoeff[34] = {2, 0, 2,-1}
    sgp_bCoeff[35] = {2,-1, 1,-1}
    sgp_bCoeff[36] = {2, 0,-2, 1}
    sgp_bCoeff[37] = {0, 0, 3,-1}
    sgp_bCoeff[38] = {2, 0, 2, 1}
    sgp_bCoeff[39] = {2, 0,-3,-1}
    sgp_bCoeff[40] = {2, 1,-1, 1}
    sgp_bCoeff[41] = {2, 1, 0, 1}
    sgp_bCoeff[42] = {4, 0, 0, 1}
    sgp_bCoeff[43] = {2,-1, 1, 1}
    sgp_bCoeff[44] = {2,-2, 0,-1}
    sgp_bCoeff[45] = {0, 0, 1, 3}
    sgp_bCoeff[46] = {2, 1, 1,-1}
    sgp_bCoeff[47] = {1, 1, 0,-1}
    sgp_bCoeff[48] = {1, 1, 0, 1}
    sgp_bCoeff[49] = {0, 1,-2,-1}
    sgp_bCoeff[50] = {2, 1,-1,-1}
    sgp_bCoeff[51] = {1, 0, 1, 1}
    sgp_bCoeff[52] = {2,-1,-2,-1}
    sgp_bCoeff[53] = {0, 1, 2, 1}
    sgp_bCoeff[54] = {4, 0,-2,-1}
    sgp_bCoeff[55] = {4,-1,-1,-1}
    sgp_bCoeff[56] = {1, 0, 1,-1}
    sgp_bCoeff[57] = {4, 0, 1,-1}
    sgp_bCoeff[58] = {1, 0,-1,-1}
    sgp_bCoeff[59] = {4,-1, 0,-1}
    sgp_bCoeff[60] = {2,-2, 0, 1}


    sgp_lTerms = {
         6288774,
         1274027,
          658314,
          213618,
         -185116,
         -114332,
           58793,
           57066,
           53322,
           45758,
          -40923,
          -34720,
          -30383,
           15327,
          -12528,
           10980,
           10675,
           10034,
            8548,
           -7888,
           -6766,
           -5163,
            4987,
            4036,
            3994,
            3861,
            3665,
           -2689,
           -2602,
            2390,
           -2348,
            2236,
           -2120,
           -2069,
            2048,
           -1773,
           -1595,
            1215,
           -1110,
            -892,
            -810,
             759,
            -713,
            -700,
             691,
             596,
             549,
             537,
             520,
            -487,
            -399,
            -381,
             351,
            -340,
             330,
             327,
            -323,
             299,
             294,
               0
    }

    sgp_rTerms = {
       -20905355,
        -3699111,
        -2955968,
         -569925,
           48888,
           -3149,
          246158,
         -152138,
         -170733,
         -204586,
         -129620,
          108743,
          104755,
           10321,
               0,
           79661,
          -34782,
          -23210,
          -21636,
           24208,
           30824,
           -8379,
          -16675,
          -12831,
          -10445,
          -11650,
           14403,
           -7003,
               0,
           10056,
            6322,
           -9884,
            5751,
               0,
           -4950,
            4130,
               0,
           -3958,
               0,
            3258,
            2616,
           -1897,
           -2117,
            2354,
               0,
               0,
           -1423,
           -1117,
           -1571,
           -1739,
               0,
           -4421,
               0,
               0,
               0,
               0,
            1165,
               0,
               0,
            8752
    }

    sgp_bTerms = {
         5128122,
          280602,
          277693,
          173237,
           55413,
           46271,
           32573,
           17198,
            9266,
            8822,
            8216,
            4324,
            4200,
           -3359,
            2463,
            2211,
            2065,
           -1870,
            1828,
           -1794,
           -1749,
           -1565,
           -1491,
           -1475,
           -1410,
           -1344,
           -1335,
            1107,
            1021,
             833,
             777,
             671,
             607,
             596,
             491,
            -451,
             439,
             422,
             421,
            -366,
            -351,
             331,
             315,
             302,
            -283,
            -229,
             223,
             223,
            -220,
            -220,
            -185,
             181,
            -177,
             176,
             166,
            -164,
             132,
            -119,
             115,
             107
    }

end




function SF_readInput()
    if sf_primer_calculo then
        sf_entrada = nil
        sf_entrada_ant = Controls.read()
        sf_acel_x = 0
        sf_acel_y = 0
        sf_moving_sky = false
    else
        sf_entrada = Controls.read()

        sf_analog_x = sf_entrada:analogX()
        sf_analog_y = sf_entrada:analogY()

        if sf_analog_x > 30 or sf_analog_x < -30 or sf_analog_y > 30 or sf_analog_y < -30 then
            sf_acel_x = sf_acel_x + sf_analog_x * 0.01
            sf_acel_y = sf_acel_y - sf_analog_y * 0.01
            sf_star_update_current_rate = 1
            sf_moving_sky = true
        else
            sf_acel_x = sf_acel_x * 0.5
            sf_acel_y = sf_acel_y * 0.5
            if math.abs(sf_acel_x) < 0.1 and math.abs(sf_acel_y) < 0.1 then
                sf_acel_x = 0
                sf_acel_y = 0
                sf_moving_sky = false
            end
        end
        if sf_r_pressed and sf_zoom_mode then
            sf_sky.rotacion = sf_sky.rotacion - sf_acel_x * sf_sky.orientacion
            if sf_sky.rotacion > 360 then
                sf_sky.rotacion = sf_sky.rotacion - 360
            end
            if sf_sky.rotacion < 0 then
                sf_sky.rotacion = sf_sky.rotacion + 360
            end
        elseif sf_zoom_mode then
            local total = sf_acel_x + sf_acel_y
            sf_sky.radio = sf_sky.radio + total
            if sf_sky.radio < 130 then
                sf_sky.radio = 130
            end

            sf_sky.centro.x = sf_sky.centro.x + ((sf_sky.centro.x - 240)*((sf_sky.radio/(sf_sky.radio - total))-1))
            sf_sky.centro.y = sf_sky.centro.y + ((sf_sky.centro.y - 136)*((sf_sky.radio/(sf_sky.radio - total))-1))

            local distancia = math.sqrt( ((sf_sky.centro.x - 240)*(sf_sky.centro.x - 240)) + ((sf_sky.centro.y - 136)*(sf_sky.centro.y - 136)) )

            if distancia > sf_sky.radio then
                sf_sky.centro.x = sf_sky.centro.x - ((sf_sky.centro.x - 240)*((sf_sky.radio/(sf_sky.radio - total))-1))
                sf_sky.centro.y = sf_sky.centro.y - ((sf_sky.centro.y - 136)*((sf_sky.radio/(sf_sky.radio - total))-1))
            end
        else
            sf_sky.centro.x = sf_sky.centro.x - sf_acel_x
            sf_sky.centro.y = sf_sky.centro.y + sf_acel_y
            local distancia = math.sqrt( ((sf_sky.centro.x - 240)*(sf_sky.centro.x - 240)) + ((sf_sky.centro.y - 136)*(sf_sky.centro.y - 136)) )

            if distancia > sf_sky.radio then
                sf_acel_x = -sf_acel_x
                sf_acel_y = -sf_acel_y
            end
        end

        if sf_entrada == sf_entrada_ant then
            return
        end



        sf_zoom_mode = false

        --L y R
        sf_r_pressed = sf_entrada:r()
        sf_l_pressed = sf_entrada:l()


        -- CRUZ
        if sf_entrada:cross() then
            sf_entrada_ant = sf_entrada
            SF_drawAllNextVisiblePassList()

        -- CIRCULO
        elseif sf_entrada:circle() then
            sf_entrada_ant = sf_entrada
            if sf_vision_nocturna then
                sf_vision_nocturna = false
                SF_changePalette (sf_color_day.r,sf_color_day.g,sf_color_day.b)
            else
                sf_vision_nocturna = true
                SF_changePalette (sf_color_night.r,sf_color_night.g,sf_color_night.b)
            end

        --TRIANGULO
        elseif sf_entrada:triangle() then
            sf_entrada_ant = sf_entrada
            if sf_iss ~= nil then
                SF_drawSatNextVisiblePassList(sf_iss)
            end
        --CUADRADO
        elseif sf_entrada:square() then
            sf_entrada_ant = sf_entrada
            sf_zoom_mode = true

        elseif sf_entrada:up() then
            if sgp_mag_limit + 0.2 <= sgp_mag_max + 0.1 then
                sgp_mag_limit = sgp_mag_limit + 0.2
            end
        elseif sf_entrada:down() then
            if sgp_mag_limit - 0.2 >= -2.1 then
                sgp_mag_limit = sgp_mag_limit - 0.2
            end
        elseif sf_entrada:left() then
            if sf_sky.orientacion < 0 then
                sf_sky.orientacion = 1.0
            else
                sf_sky.orientacion = -1.0
            end
        elseif sf_entrada:right() then
            if sf_sky.orientacion < 0 then
                sf_sky.orientacion = 1.0
            else
                sf_sky.orientacion = -1.0
            end



--      elseif sf_entrada:hold() then
--      elseif sf_entrada:note() then

        elseif sf_entrada:select() then
            SF_downloadTLEs()
            sgp_sat_number = 0 -- esta variable tiene que ser cero y se modifica por SGP_getTLE()
            SGP_getTLE("./tle/visual.tle")
            SGP_getTLE("./tle/iridium.tle")
            SF_initTails()

            if sgp_sat_number == -1 then
                screen.print(30, 150, "Error: Archivos TLE corruptos." , sf_palette[1])
                screen.waitvblankstart()
                screen.flip()
                screen.print(30, 150, "Error: Archivos TLE corruptos." , sf_palette[1])
                screen.waitvblankstart(300)
                screen.flip()
                sgp_sat_number = 0
            else
                screen.print(30, 150, "OK! (".. sgp_sat_number..")" , sf_palette[1])
                screen.waitvblankstart()
                screen.flip()
                screen.print(30, 150, "OK! (".. sgp_sat_number.." satelites)" , sf_palette[1])
                screen.waitvblankstart(200)
                screen.flip()
            end


--      elseif entrada:home() then
        elseif sf_entrada:start() then
            SF_cambiarConfiguracion()

        elseif sf_l_pressed and sf_r_pressed then
            SF_screenshot()

        end

        sf_entrada_ant = sf_entrada
    end
end

function SF_screenshot()
    screen.toimage():save("../../../../PICTURE/captura_"..sgp_time.year.."_"..sgp_time.month.."_".. sgp_time.day.."_".. sgp_time.hour.."_".. sgp_time.min.."_".. sgp_time.sec..".png")
    SF_erase (0,262,80)
    screen.print(0, 262, "Screenshot saved in a PNG file.",  sf_color_white)
    screen.waitvblankstart()
    screen.flip()
    screen.waitvblankstart(200)
end

function SF_constants()

    const_xmnpda = 1440.0
    -- Constante gravitacional de la tierra
    const_ge = 398600.8
    const_ae = 1.0
    const_tothrd = 2.0/3.0
    -- Radio ecuatorial de la tierra en kilómetros
    const_xkmper = 6378.135
    -- Achatamiento de la tierra
    const_f = 1.0/298.26
    -- Armónico J2
    const_J2 = 1.0826158e-3
    -- Armónico J3
    const_J3 = -2.53881e-6
    -- Armónico J4
    const_J4 = -1.65597e-6
    const_ck2 = const_J2/2.0
    const_ck4 = -3.0*const_J4/8.0
    const_xj3 = const_J3
    const_qo = const_ae + (120.0/const_xkmper)
    const_s = const_ae + (78/const_xkmper)
    const_e6a = 0.000001
    -- Código de inialización del modelo Deep-Space
    const_dpinit = 1
    -- Código secular del modelo Deep-Space
    const_dpsec = 2
    -- Código periódico del modelo Deep-Space
    const_dpper = 3
    -- Radio solar en kilómetros
    const_sr = 696000.0
    -- Unidad Astronómica (distancia de la Tierra al Sol en kilómetros)
    const_AU = 1.49597870e8
    -- Minutos por dia
    const_xmnpda = 1440.0
    -- Segundos por dia
    const_secday = 86400.0
    -- Rotaciones de la tierra por día sideral (no-constante)
    const_omega_E = 1.00273790934
    -- Rotacion de la tierra, radianes por dia sideral
    const_omega_ER = const_omega_E*(math.pi*2.0)
    -- Sqrt(ge) ER^3/min^2
    const_xke = math.sqrt(3600.0*const_ge/(const_xkmper^3))
    -- (qo-s)^4 ER^4
    const_qoms2t = (const_qo-const_s)^4
    -- Twilight elevations
    const_twilightCivil = -6
    const_twilightNautical = -12
    const_twilightAstronomical = -18
    const_mfactor = (math.pi*2.0)*const_omega_E/const_secday

    const_julian_minute = 0.000694446


    --Constantes para calcular la posicion de la luna

    const_epoch =   2444238.5      --1980 January 0.0

    --Constants defining the Sun's apparent orbit

    const_elonge    =   278.833540     --Ecliptic longitude of the Sun at epoch 1980.0
    const_elongp    =   282.596403     --Ecliptic longitude of the Sun at perigee
    const_eccent    =   0.016718       --Eccentricity of Earth's orbit
    const_sunangsiz =   0.533128       --Sun's angular size, degrees, at semi-major axis distance
    const_AstronomicalUnit =  149597870.0       -- Astronomical unit in kilometres
    const_SunSMAX   =  (const_AstronomicalUnit * 1.000001018) -- Semi-major axis of Earth's orbit

    --Elements of the Moon's orbit, epoch 1980.0
    const_mmlong    =   64.975464      --Moon's mean longitude at the epoch
    const_mmlongp   =   349.383063     --Mean longitude of the perigee at the epoch
    const_mlnode    =   151.950429     --Mean longitude of the node at the epoch
    const_minc      =   5.145396       --Inclination of the Moon's orbit
    const_mecc      =   0.054900       --Eccentricity of the Moon's orbit
    const_mangsiz   =   0.5181         --Moon's angular size at distance a from Earth
    const_msmax     =   384401.0       --Semi-major axis of Moon's orbit in km
    const_mparallax =   0.9507         --Parallax at distance a from Earth

    const_SynMonth  =   29.53058868

    const_JulianCentury =   36525.0 -- Days in Julian century
    const_J2000 =   2451545.0

    const_NTERMS =  60

end


function SF_loadConfigFromFile(filename)
    -- Miramos primero que el fichero exista
    local file = io.open(filename)
    if file then
        io.close(file)
    else
        return false
    end

    for line in io.lines(filename) do
        local c = string.find(line," ",1,true)
        local str = string.sub(line,1,c-1)
        if str == "sun_and_moon" then
            sf_sky.show.sunAndMoon = (string.sub(line,c+1,string.len(line)) == "true")
        elseif str == "satellites" then
            sf_sky.show.satellites = (string.sub(line,c+1,string.len(line)) == "true")
        elseif str == "stars" then
            sf_sky.show.stars = (string.sub(line,c+1,string.len(line)) == "true")
        elseif str == "auto_magnitude" then
            sf_sky.show.autoMagStars = (string.sub(line,c+1,string.len(line)) == "true")
        elseif str == "satellite_names" then
            sf_sky.show.satelliteNames = (string.sub(line,c+1,string.len(line)) == "true")
        elseif str == "constellation_names" then
            sf_sky.show.constellationNames = (string.sub(line,c+1,string.len(line)) == "true")
        elseif str == "elevation_lines" then
            sf_sky.show.elevationLines = (string.sub(line,c+1,string.len(line)) == "true")
        elseif str == "color_day_r" then
            sf_color_day.r = tonumber(string.sub(line,c+1,string.len(line)))
        elseif str == "color_day_g" then
            sf_color_day.g = tonumber(string.sub(line,c+1,string.len(line)))
        elseif str == "color_day_b" then
            sf_color_day.b = tonumber(string.sub(line,c+1,string.len(line)))
        elseif str == "color_night_r" then
            sf_color_night.r = tonumber(string.sub(line,c+1,string.len(line)))
        elseif str == "color_night_g" then
            sf_color_night.g = tonumber(string.sub(line,c+1,string.len(line)))
        elseif str == "color_night_b" then
            sf_color_night.b = tonumber(string.sub(line,c+1,string.len(line)))
        end
    end

    return true

end

function SF_saveConfigToFile ( filename )
    local f = io.open (filename, "w+")

    if sf_sky.show.sunAndMoon then
        f:write("sun_and_moon true\n")
    else
        f:write("sun_and_moon false\n")
    end

    if sf_sky.show.satellites then
        f:write("satellites true\n" )
    else
        f:write("satellites false\n")
    end

    if sf_sky.show.stars then
        f:write("stars true\n" )
    else
        f:write("stars false\n")
    end

    if sf_sky.show.autoMagStars then
        f:write("auto_magnitude true\n")
    else
        f:write("auto_magnitude false\n")
    end

    if sf_sky.show.satelliteNames then
        f:write("satellite_names true\n" )
    else
        f:write("satellite_names false\n")
    end

    if sf_sky.show.constellationNames then
        f:write("constellation_names true\n" )
    else
        f:write("constellation_names false\n")
    end

    if sf_sky.show.elevationLines then
        f:write("elevation_lines true\n" )
    else
        f:write("elevation_lines false\n")
    end

    f:write("color_day_r "..sf_color_day.r .. "\n")
    f:write("color_day_g "..sf_color_day.g .. "\n")
    f:write("color_day_b "..sf_color_day.b .. "\n")
    f:write("color_night_r "..sf_color_night.r .. "\n")
    f:write("color_night_g "..sf_color_night.g .. "\n")
    f:write("color_night_b "..sf_color_night.b .. "\n")

    f:flush()
    io.close(f)

end

function SF_cambiarConfiguracion()
    local linea = 1
    local opciones = 15

    local changed = false

    local current_lat, current_lon, current_alt
    local NS, EW

    if sgp_location.lat >= 0 then
        current_lat = string.format ("%.2f",sgp_location.lat)
        NS = "N"
    else
        current_lat = string.format ("%.2f",sgp_location.lat*-1)
        NS = "S"
    end
    if sgp_location.lat < 10.0 and sgp_location.lat > -10.0 then
        current_lat = "0" .. current_lat
    end

    if sgp_location.lon >= 0 then
        current_lon = string.format ("%.2f",sgp_location.lon)
        EW = "E"
    else
        current_lon = string.format ("%.2f",sgp_location.lon*-1)
        EW = "W"
    end

    if sgp_location.lon < 100.0 and sgp_location.lon > -100.0 then
        current_lon = "0" .. current_lon
    end
    if sgp_location.lon < 10.0 and sgp_location.lon > -10.0 then
        current_lon = "0" .. current_lon
    end

    current_alt = string.format ("%04d",sgp_location.alt)


    current_UTC_offset = "GMT" .. string.format ("%+03d",sgp_location.UTC_offset)
    current_name = sgp_location.name


    local pintar_cursor = true
    local cursor_x = 428
    repeat
        screen.clear(sf_sky_color)
        screen.print(1,1,"----- OPCIONES ------------------------------------------------------", sf_palette[1])
        SF_drawInfoBar(false)
        screen.print(1,11, "Elementos del cielo disponibles:" , sf_palette[8])

        screen.print(1, 21, "    - Sol y Luna" , sf_palette[4])
        if sf_sky.show.sunAndMoon then
            screen.print(420, 21, "[x]" , sf_palette[4])
        else
            screen.print(420, 21, "[ ]" , sf_palette[4])
        end

        screen.print(1,31, "    - Satelites" , sf_palette[4])
        if sf_sky.show.satellites then
            screen.print(420, 31, "[x]" , sf_palette[4])
        else
            screen.print(420, 31, "[ ]" , sf_palette[4])
        end


        screen.print(1,41, "    - Estrellas" , sf_palette[4])
        if sf_sky.show.stars then
            screen.print(420, 41, "[x]" , sf_palette[4])
        else
            screen.print(420, 41, "[ ]" , sf_palette[4])
        end

        screen.print(1,51, "    - Magnitud de estrellas automatico" , sf_palette[4])
        if sf_sky.show.autoMagStars then
            screen.print(420, 51, "[x]" , sf_palette[4])
        else
            screen.print(420, 51, "[ ]" , sf_palette[4])
        end

        screen.print(1,61, "    - Nombre de los satelites" , sf_palette[4])
        if sf_sky.show.satelliteNames then
            screen.print(420, 61, "[x]" , sf_palette[4])
        else
            screen.print(420, 61, "[ ]" , sf_palette[4])
        end


        screen.print(1, 71, "    - Nombre de las constelaciones" , sf_palette[4])
        if sf_sky.show.constellationNames then
            screen.print(420, 71, "[x]" , sf_palette[4])
        else
            screen.print(420, 71, "[ ]" , sf_palette[4])
        end

        screen.print(1, 81, "    - Lineas de referencia en 30, 60 y 90 grados" , sf_palette[4])
        if sf_sky.show.elevationLines then
            screen.print(420, 81, "[x]" , sf_palette[4])
        else
            screen.print(420, 81, "[ ]" , sf_palette[4])
        end

        screen.print(1, 91,  "Coordenadas de localizacion:" , sf_palette[8])
        screen.print(1, 101, "    - Latitud", sf_palette[4])
        screen.print(380, 101, "[" .. current_lat .. NS .. "]", sf_palette[4])
        screen.print(1, 111, "    - Longitud", sf_palette[4])
        screen.print(372, 111, "[" .. current_lon .. EW .. "]", sf_palette[4])
        screen.print(1, 121, "    - Altitud (en metros)", sf_palette[4])
        screen.print(396, 121, "[" .. current_alt .. "]" , sf_palette[4])
        screen.print(1, 131, "    - Zona horaria", sf_palette[4])
        screen.print(380, 131, "[" .. current_UTC_offset .. "]" , sf_palette[4])
        screen.print(1, 141,  "Colores de dia y noche:" , sf_palette[8])
        screen.print(1, 151, "    - Dia:",sf_palette[4])
        screen.print(124, 151, "Rojo ["..string.format ("%03d",sf_color_day.r).."]    Verde ["..string.format ("%03d",sf_color_day.g).."]     Azul ["..string.format ("%03d",sf_color_day.b).."]", sf_palette[4])
        screen.print(1, 161, "    - Noche:",sf_palette[4])
        screen.print(124, 161, "Rojo ["..string.format ("%03d",sf_color_night.r).."]    Verde ["..string.format ("%03d",sf_color_night.g).."]     Azul ["..string.format ("%03d",sf_color_night.b).."]", sf_palette[4])
        screen.print(1, 251, "Pulsa X para modificar la opcion seleccionada.", sf_palette[8])
        screen.print(1, 261, "Pulsa O para salir de las opciones.", sf_palette[8])

        if pintar_cursor then
            screen.print(cursor_x,13 + 10 * linea, "_", sf_palette[1])
            pintar_cursor = false
        else
            pintar_cursor = true
        end

        screen.waitvblankstart()
        screen.flip()


        sf_entrada = Controls.read()
        if sf_entrada:up() then
            if linea > 1 then
                linea = linea - 1
                if linea == 8 then
                    linea = linea - 1
                end
            end
            pintar_cursor = true
        elseif sf_entrada:down() then
            if linea < opciones then
                linea = linea + 1
                if linea == 8 then
                    linea = linea + 1
                elseif linea == 13 then
                    linea = linea + 1
                end

            end
            pintar_cursor = true
        elseif sf_entrada ~= sf_entrada_ant then
            sf_entrada_ant = sf_entrada
            if sf_entrada:cross() then
                if linea == 1 then
                    sf_sky.show.sunAndMoon = not sf_sky.show.sunAndMoon
                elseif linea == 2 then
                    sf_sky.show.satellites = not sf_sky.show.satellites
                elseif linea == 3 then
                    sf_sky.show.stars = not sf_sky.show.stars
                elseif linea == 4 then
                    sf_sky.show.autoMagStars = not sf_sky.show.autoMagStars
                elseif linea == 5 then
                    sf_sky.show.satelliteNames = not sf_sky.show.satelliteNames
                elseif linea == 6 then
                    sf_sky.show.constellationNames = not sf_sky.show.constellationNames
                elseif linea == 7 then
                    sf_sky.show.elevationLines = not sf_sky.show.elevationLines
                elseif linea == 9 then
                    SF_editLatitud()
                    if sgp_location.lat >= 0 then
                        current_lat = string.format ("%.2f",sgp_location.lat)
                        NS = "N"
                    else
                        current_lat = string.format ("%.2f",sgp_location.lat*-1)
                        NS = "S"
                    end
                    if sgp_location.lat < 10.0 and sgp_location.lat > -10.0 then
                        current_lat = "0" .. current_lat
                    end
                    changed = true
                elseif linea == 10 then
                    SF_editLongitud()
                    if sgp_location.lon >= 0 then
                        current_lon = string.format ("%.2f",sgp_location.lon)
                        EW = "E"
                    else
                        current_lon = string.format ("%.2f",sgp_location.lon*-1)
                        EW = "W"
                    end

                    if sgp_location.lon < 100.0 and sgp_location.lon > -100.0 then
                        current_lon = "0" .. current_lon
                    end
                    if sgp_location.lon < 10.0 and sgp_location.lon > -10.0 then
                        current_lon = "0" .. current_lon
                    end
                    changed = true
                elseif linea == 11 then
                    SF_editAltitud()
                    current_alt = string.format ("%04d",sgp_location.alt)
                    changed = true
                elseif linea == 12 then
                    SF_editUtcOffset()
                    current_UTC_offset = "GMT" .. string.format ("%+03d",sgp_location.UTC_offset)
                    changed = true
                elseif linea == 14 then
                    SF_editColorDay()
                    if sf_vision_nocturna then
                        SF_changePalette (sf_color_night.r,sf_color_night.g,sf_color_night.b)
                    else
                        SF_changePalette (sf_color_day.r,sf_color_day.g,sf_color_day.b)
                    end
                elseif linea == 15 then
                    SF_editColorNight()
                    if sf_vision_nocturna then
                        SF_changePalette (sf_color_night.r,sf_color_night.g,sf_color_night.b)
                    else
                        SF_changePalette (sf_color_day.r,sf_color_day.g,sf_color_day.b)
                    end
                end

            end
        end

        sf_entrada_ant = sf_entrada
        screen.waitvblankstart(10)
    until sf_entrada:circle()

    if changed then
        SF_initTails()
        SF_enableAllSatellites()
        SF_enableAllStars()
        sgp_location.name = "Personalizado"
        sgp_location.polar.lat = math.rad(sgp_location.lat)
        sgp_location.polar.lon = math.rad(SGP_modulus(sgp_location.lon,360))
        sgp_location.polar.alt = sgp_location.alt * 0.001
    end
    SF_saveConfigToFile ("config.txt")

end

function SF_editLatitud()
    local current_lat
    local NS

    if sgp_location.lat >= 0 then
        current_lat = string.format ("%.2f",sgp_location.lat)
        NS = "N"
    else
        current_lat = string.format ("%.2f",sgp_location.lat*-1)
        NS = "S"
    end
    if sgp_location.lat < 10.0 and sgp_location.lat > -10.0 then
        current_lat = "0" .. current_lat
    end

    --Edicion latitud
    local edit_x, edit_y, edit_pos, edit_len
    edit_x = 388
    edit_y = 101
    edit_pos = 1
    edit_len = 6
    local lat = { }
    lat[1] = string.sub(current_lat,1,1)
    lat[2] = string.sub(current_lat,2,2)
    lat[3] = string.sub(current_lat,3,3)
    lat[4] = string.sub(current_lat,4,4)
    lat[5] = string.sub(current_lat,5,5)
    lat[6] = NS

    local pintar_cursor = true
    while true do
        draw.fillrect(edit_x, edit_y, edit_len * 8 , 9, sf_color_black)
        screen.print(edit_x, edit_y, lat[1] .. lat[2] .. lat[3] .. lat[4] .. lat[5] .. lat[6] .. "]",sf_palette[1])
        if pintar_cursor then
            screen.print(edit_x + (edit_pos-1) * 8,edit_y + 2, "_", sf_palette[1])
            pintar_cursor = false
        else
            pintar_cursor = true
        end

        screen.waitvblankstart()
        screen.flip()

        sf_entrada = Controls.read()


        if sf_entrada:right() then
            if edit_pos < edit_len then
                edit_pos = edit_pos + 1
            end
            pintar_cursor = true
        elseif sf_entrada:left() then
            if edit_pos > 1 then
                edit_pos = edit_pos - 1
            end
            pintar_cursor = true
        elseif sf_entrada:up() then
            if edit_pos == 1 or edit_pos == 2 or edit_pos == 4 or edit_pos == 5 then
                if tonumber(lat[edit_pos]) < 9 then
                    lat[edit_pos] = lat[edit_pos] + 1
                end
            elseif edit_pos == 6 then
                lat[edit_pos] = "N"
            end
            pintar_cursor = true
        elseif sf_entrada:down() then
            if edit_pos == 1 or edit_pos == 2 or edit_pos == 4 or edit_pos == 5 then
                if tonumber(lat[edit_pos]) > 0 then
                    lat[edit_pos] = lat[edit_pos] - 1
                end
            elseif edit_pos == 6 then
                lat[edit_pos] = "S"
            end
            pintar_cursor = true
        elseif sf_entrada ~= sf_entrada_ant then
            sf_entrada_ant = sf_entrada
            if sf_entrada:cross() then
                if lat[6] == "N" then
                    sgp_location.lat = tonumber(lat[1]..lat[2]..lat[3]..lat[4]..lat[5])
                else
                    sgp_location.lat = -tonumber(lat[1]..lat[2]..lat[3]..lat[4]..lat[5])
                end
                return
            end
        end

        if lat[1] == 9 then
            lat[2] = 0
            lat[4] = 0
            lat[5] = 0
        end

        sf_entrada_ant = sf_entrada

        screen.waitvblankstart(10)
    end



end

function SF_editLongitud()
    if sgp_location.lon >= 0 then
        current_lon = string.format ("%.2f",sgp_location.lon)
        EW = "E"
    else
        current_lon = string.format ("%.2f",sgp_location.lon*-1)
        EW = "W"
    end

    if sgp_location.lon < 100.0 and sgp_location.lon > -100.0 then
        current_lon = "0" .. current_lon
    end
    if sgp_location.lon < 10.0 and sgp_location.lon > -10.0 then
        current_lon = "0" .. current_lon
    end
    --Edicion longitud

    edit_x = 380
    edit_y = 111
    edit_pos = 1
    edit_len = 7
    local lon = { }
    lon[1] = string.sub(current_lon,1,1)
    lon[2] = string.sub(current_lon,2,2)
    lon[3] = string.sub(current_lon,3,3)
    lon[4] = string.sub(current_lon,4,4)
    lon[5] = string.sub(current_lon,5,5)
    lon[6] = string.sub(current_lon,6,6)
    lon[7] = EW

    pintar_cursor = true
    while true do
        draw.fillrect(edit_x, edit_y, edit_len * 8 , 9, sf_color_black)
        screen.print(edit_x, edit_y, lon[1] .. lon[2] .. lon[3] .. lon[4] .. lon[5] .. lon[6] .. lon[7] .. "]",sf_palette[1])
        if pintar_cursor then
            screen.print(edit_x + (edit_pos-1) * 8,edit_y + 2, "_", sf_palette[1])
            pintar_cursor = false
        else
            pintar_cursor = true
        end

        screen.waitvblankstart()
        screen.flip()

        local sf_entrada = Controls.read()

        if sf_entrada:right() then
            if edit_pos < edit_len then
                edit_pos = edit_pos + 1
            end
            pintar_cursor = true
        elseif sf_entrada:left() then
            if edit_pos > 1 then
                edit_pos = edit_pos - 1
            end
            pintar_cursor = true
        elseif sf_entrada:up() then
            if edit_pos == 1 or edit_pos == 2 or edit_pos == 3 or edit_pos == 5 or edit_pos == 6 then
                if tonumber(lon[edit_pos]) < 9 then
                    lon[edit_pos] = lon[edit_pos] + 1
                end
            elseif edit_pos == 7 then
                lon[edit_pos] = "E"
            end
            pintar_cursor = true
        elseif sf_entrada:down() then
            if edit_pos == 1 or edit_pos == 2 or edit_pos == 3 or edit_pos == 5 or edit_pos == 6 then
                if tonumber(lon[edit_pos]) > 0 then
                    lon[edit_pos] = lon[edit_pos] - 1
                end
            elseif edit_pos == 7 then
                lon[edit_pos] = "W"
            end
            pintar_cursor = true
        elseif sf_entrada ~= sf_entrada_ant then
            sf_entrada_ant = sf_entrada
            if sf_entrada:cross() then
                if lon[7] == "E" then
                    sgp_location.lon = tonumber(lon[1]..lon[2]..lon[3]..lon[4]..lon[5]..lon[6])
                else
                    sgp_location.lon = tonumber(lon[1]..lon[2]..lon[3]..lon[4]..lon[5]..lon[6])*-1
                end
                return
            end
        end

        if tonumber(lon[1]) > 1 then
            lon[1] = 1
            lon[2] = 8
            lon[3] = 0
            lon[5] = 0
            lon[6] = 0
        elseif tonumber(lon[1]) == 1 and tonumber(lon[2]) > 8 then
            lon[2] = 8
            lon[3] = 0
            lon[5] = 0
            lon[6] = 0
        elseif tonumber(lon[1]) == 1 and tonumber(lon[2]) == 8 then
            lon[3] = 0
            lon[5] = 0
            lon[6] = 0
        end

        sf_entrada_ant = sf_entrada
        screen.waitvblankstart(10)
    end

end

function SF_editAltitud ()
    current_alt = string.format ("%04d",sgp_location.alt)
    --Edicion altitud
    edit_x = 404
    edit_y = 121
    edit_pos = 1
    edit_len = 4
    local alt = { }
    alt[1] = string.sub(current_alt,1,1)
    alt[2] = string.sub(current_alt,2,2)
    alt[3] = string.sub(current_alt,3,3)
    alt[4] = string.sub(current_alt,4,4)

    pintar_cursor = true
    while true do
        draw.fillrect(edit_x, edit_y, edit_len * 8 , 9, sf_color_black)
        screen.print(edit_x, edit_y, alt[1] .. alt[2] .. alt[3] .. alt[4],sf_palette[1])
        if pintar_cursor then
            screen.print(edit_x + (edit_pos-1) * 8,edit_y + 2, "_", sf_palette[1])
            pintar_cursor = false
        else
            pintar_cursor = true
        end

        screen.waitvblankstart()
        screen.flip()

        sf_entrada = Controls.read()

        if sf_entrada:right() then
            if edit_pos < edit_len then
                edit_pos = edit_pos + 1
            end
            pintar_cursor = true
        elseif sf_entrada:left() then
            if edit_pos > 1 then
                edit_pos = edit_pos - 1
            end
            pintar_cursor = true
        elseif sf_entrada:up() then
            if tonumber(alt[edit_pos]) < 9 then
                alt[edit_pos] = alt[edit_pos] + 1
            end
            pintar_cursor = true
        elseif sf_entrada:down() then
            if tonumber(alt[edit_pos]) > 0 then
                alt[edit_pos] = alt[edit_pos] - 1
            end
            pintar_cursor = true
        elseif sf_entrada ~= sf_entrada_ant then
            sf_entrada_ant = sf_entrada
            if sf_entrada:cross() then
                sgp_location.alt = tonumber(alt[1]..alt[2]..alt[3]..alt[4])
                return
            end
        end

        sf_entrada_ant = sf_entrada
        screen.waitvblankstart(10)
    end

end


function SF_editUtcOffset()

    current_UTC_offset = "GMT" .. string.format ("%+03d",sgp_location.UTC_offset)

    --Edicion UTC Offset

    edit_x = 388
    edit_y = 131
    edit_pos = 4
    edit_len = 6
    local utc_off = sgp_location.UTC_offset

    pintar_cursor = true
    while true do
        draw.fillrect(edit_x, edit_y, edit_len * 8 , 9, sf_color_black)
        screen.print(edit_x, edit_y, "GMT" .. string.format ("%+03d",utc_off),sf_palette[1])
        if pintar_cursor then
            screen.print(edit_x + (edit_pos-1) * 8,edit_y + 2, "___", sf_palette[1])
            pintar_cursor = false
        else
            pintar_cursor = true
        end

        screen.waitvblankstart()
        screen.flip()

        local sf_entrada = Controls.read()


        if sf_entrada:up() then
            if utc_off < 12 then
                utc_off = utc_off + 1
            end
        elseif sf_entrada:down() then
            if utc_off > -12 then
                utc_off = utc_off - 1
            end
        elseif sf_entrada ~= sf_entrada_ant then
            sf_entrada_ant = sf_entrada
            if sf_entrada:cross() then
                sgp_location.UTC_offset = utc_off
                return
            end
        end

        sf_entrada_ant = sf_entrada
        screen.waitvblankstart(10)
    end
end

function SF_editColorDay()
    --Edicion UTC Offset

    edit_x = 172
    edit_y = 151
    edit_pos = 2
    edit_len = 3
    edit_rgb = 1

    pintar_cursor = true
    while true do
        local edit_color = color.new(sf_color_day.r,sf_color_day.g,sf_color_day.b)
        draw.fillrect(edit_x, edit_y, edit_len * 8 , 9, sf_color_black)
        screen.print(edit_x, edit_y, string.format ("%03d",sf_color_day.r),edit_color)
        draw.fillrect(edit_x + 120, edit_y, edit_len * 8 , 9, sf_color_black)
        screen.print(edit_x+ 120, edit_y, string.format ("%03d",sf_color_day.g),edit_color)
        draw.fillrect(edit_x+ 240, edit_y, edit_len * 8 , 9, sf_color_black)
        screen.print(edit_x+ 240, edit_y, string.format ("%03d",sf_color_day.b),edit_color)
        if pintar_cursor then
            screen.print(edit_x + (edit_pos-2) * 8 + (edit_rgb-1)*120 ,edit_y + 2, "___", sf_palette[1])
            pintar_cursor = false
        else
            pintar_cursor = true
        end

        screen.waitvblankstart()
        screen.flip()

        local sf_entrada = Controls.read()


        if sf_entrada:up() then
            if edit_rgb == 1 then
                if sf_color_day.r + 5 <= 255 then
                    sf_color_day.r = sf_color_day.r + 5
                end
            elseif edit_rgb == 2 then
                if sf_color_day.g + 5 <= 255 then
                    sf_color_day.g = sf_color_day.g + 5
                end
            elseif edit_rgb == 3 then
                if sf_color_day.b + 5 <= 255 then
                    sf_color_day.b = sf_color_day.b + 5
                end
            end
        elseif sf_entrada:down() then
            if edit_rgb == 1 then
                if sf_color_day.r - 5 >= 0 then
                    sf_color_day.r = sf_color_day.r - 5
                end
            elseif edit_rgb == 2 then
                if sf_color_day.g - 5 >= 0 then
                    sf_color_day.g = sf_color_day.g - 5
                end
            elseif edit_rgb == 3 then
                if sf_color_day.b - 5 >= 0 then
                    sf_color_day.b = sf_color_day.b - 5
                end
            end
        elseif sf_entrada ~= sf_entrada_ant then
            sf_entrada_ant = sf_entrada
            if sf_entrada:left() then
                if edit_rgb > 1 then
                    edit_rgb = edit_rgb - 1
                end
            elseif sf_entrada:right() then
                if edit_rgb < 3 then
                    edit_rgb = edit_rgb + 1
                end
            elseif sf_entrada:cross() then
                return
            end
        end

        sf_entrada_ant = sf_entrada
        screen.waitvblankstart(10)
    end
end

function SF_editColorNight()
    --Edicion UTC Offset

    edit_x = 172
    edit_y = 161
    edit_pos = 2
    edit_len = 3
    edit_rgb = 1

    pintar_cursor = true
    while true do
        local edit_color = color.new(sf_color_night.r,sf_color_night.g,sf_color_night.b)
        draw.fillrect(edit_x, edit_y, edit_len * 8 , 9, sf_color_black)
        screen.print(edit_x, edit_y, string.format ("%03d",sf_color_night.r),edit_color)
        draw.fillrect(edit_x + 120, edit_y, edit_len * 8 , 9, sf_color_black)
        screen.print(edit_x+ 120, edit_y, string.format ("%03d",sf_color_night.g),edit_color)
        draw.fillrect(edit_x+ 240, edit_y, edit_len * 8 , 9, sf_color_black)
        screen.print(edit_x+ 240, edit_y, string.format ("%03d",sf_color_night.b),edit_color)
        if pintar_cursor then
            screen.print(edit_x + (edit_pos-2) * 8 + (edit_rgb-1)*120 ,edit_y + 2, "___", sf_palette[1])
            pintar_cursor = false
        else
            pintar_cursor = true
        end

        screen.waitvblankstart()
        screen.flip()

        local sf_entrada = Controls.read()


        if sf_entrada:up() then
            if edit_rgb == 1 then
                if sf_color_night.r + 5 <= 255 then
                    sf_color_night.r = sf_color_night.r + 5
                end
            elseif edit_rgb == 2 then
                if sf_color_night.g + 5 <= 255 then
                    sf_color_night.g = sf_color_night.g + 5
                end
            elseif edit_rgb == 3 then
                if sf_color_night.b + 5 <= 255 then
                    sf_color_night.b = sf_color_night.b + 5
                end
            end
        elseif sf_entrada:down() then
            if edit_rgb == 1 then
                if sf_color_night.r - 5 >= 0 then
                    sf_color_night.r = sf_color_night.r - 5
                end
            elseif edit_rgb == 2 then
                if sf_color_night.g - 5 >= 0 then
                    sf_color_night.g = sf_color_night.g - 5
                end
            elseif edit_rgb == 3 then
                if sf_color_night.b - 5 >= 0 then
                    sf_color_night.b = sf_color_night.b - 5
                end
            end
        elseif sf_entrada ~= sf_entrada_ant then
            sf_entrada_ant = sf_entrada
            if sf_entrada:left() then
                if edit_rgb > 1 then
                    edit_rgb = edit_rgb - 1
                end
            elseif sf_entrada:right() then
                if edit_rgb < 3 then
                    edit_rgb = edit_rgb + 1
                end
            elseif sf_entrada:cross() then
                return
            end
        end

        sf_entrada_ant = sf_entrada
        screen.waitvblankstart(10)
    end
end

function SF_enableAllSatellites()
    local s
    for s = 1,sgp_sat_number do
        sgp_sats[s].no_calcular = 0
    end
end


function SF_enableAllStars()
    local s
    for s = 1,sgp_star_number do
        sgp_stars[s].no_calcular    = 0
    end
end

function SF_sendHTTPheader(sock, filepath)
  sock:send("GET " .. filepath .. " HTTP/1.1\r\n")
  sock:send("Host: celestrak.com\r\n")
  sock:send("User-Agent: Satfinder 1.3\r\n")
  sock:send("Accept: */*;q=0.01\r\n")
  sock:send("Keep-Alive: 300\r\n")
  sock:send("Connection: keep-alive\r\n")
  sock:send("\r\n")
end

function SF_downloadTLEs()
    local tle_filename = "visual"
    sf_iss = nil

    screen.clear(sf_sky_color)
    screen.print(30, 0,"> Inicializando conexion WIFI...", sf_palette[4])
    screen.waitvblankstart()
    screen.flip()
    screen.clear(sf_sky_color)
    screen.print(30, 0,"> Inicializando conexion WIFI...", sf_palette[4])
    screen.waitvblankstart()
    screen.flip()
    screen.waitvblankstart(200)

    -- Inicializar modulo WIFI
    while not ipAddress do
        os.sleep(0.01*100)
        wlan.init()
        wifi, ipAddress = pcall(function() return wlan.getIP() end)
        if wifi == false then
            ipAddress = false
            os.message("No fue posible el acceso a Internet. Por favor, conectese a un punto de acceso.",0)
            wlan.init()
        end
    end

    screen.print(30, 0,"> Inicializando conexion WIFI...", sf_palette[4])
    screen.print(30, 10, "> Obteniendo direccion IP... ".. ipAddress , sf_palette[4])
    screen.waitvblankstart()
    screen.flip()

    screen.print(30, 0,"> Inicializando conexion WIFI...", sf_palette[4])
    screen.print(30, 10, "> Obteniendo direccion IP... ".. ipAddress , sf_palette[4])
    screen.waitvblankstart()
    screen.flip()

    screen.print(30, 20, "> Conectando con Celestrak.com..." , sf_palette[1])
    screen.waitvblankstart()
    screen.flip()

    screen.print(30, 20, "> Conectando con Celestrak.com..." , sf_palette[1])
    screen.waitvblankstart()
    screen.flip()

    socket,error = Socket.connect("celestrak.com", 80)
    while not socket:isConnected() do
        os.sleep(0.01*100)
    end

    screen.print(300, 20, "conectado!. ", sf_palette[1])
    screen.waitvblankstart()
    screen.flip()

    screen.print(300, 20, "conectado!. ", sf_palette[1])
    screen.waitvblankstart()
    screen.flip()

    SF_sendHTTPheader(socket, "/NORAD/elements/".. tle_filename ..".txt")

    screen.print(30, 30, "> Recibiendo archivo " .. tle_filename .. ".tle", sf_palette[4])
    screen.waitvblankstart()
    screen.flip()
    screen.print(30, 30, "> Recibiendo archivo " .. tle_filename .. ".tle ...", sf_palette[4])
    screen.waitvblankstart()
    screen.flip()


    -- Obtenemos el fichero TLE
    local f = io.open ("./tle/"..tle_filename .. ".tle", "w+")
    local buffer_len = 1
    reintentos = 20
    while (buffer_len > 0) do
        screen.waitvblankstart(5)
        local buffer = socket:recv(500)
        if string.len(buffer) > 0 then
            f:write (buffer)
            screen.waitvblankstart(5)
            screen.flip()
            screen.waitvblankstart(5)
            screen.flip()
            buffer_len = string.len(buffer)
            reintentos = 20
        else
            if reintentos > 0 then
                reintentos = reintentos - 1
                screen.waitvblankstart(10)
                screen.flip()
                screen.waitvblankstart(10)
                screen.flip()
                buffer_len = 1
            else
                buffer_len = string.len(buffer)
            end
        end
    end
    f:flush ()
    io.close (f)
    socket:close()
    screen.print(30, 30, "> Recibiendo archivo " .. tle_filename .. ".tle ... OK!", sf_palette[4])
    screen.waitvblankstart()
    screen.flip()
    screen.print(30, 30, "> Recibiendo archivo " .. tle_filename .. ".tle ... OK!", sf_palette[4])
    screen.waitvblankstart(300)
    screen.flip()

    tle_filename = "iridium"


    screen.print(30, 40, "> Conectando con Celestrak.com..." , sf_palette[1])
    screen.waitvblankstart()
    screen.flip()

    screen.print(30, 40, "> Conectando con Celestrak.com..." , sf_palette[1])
    screen.waitvblankstart()
    screen.flip()


    socket,error = Socket.connect("celestrak.com", 80)
    while not socket:isConnected() do
        os.sleep(0.01*100)
    end


    screen.print(300, 40, "conectado!. ", sf_palette[1])
    screen.waitvblankstart()
    screen.flip()

    screen.print(300, 40, "conectado!. ", sf_palette[1])
    screen.waitvblankstart()
    screen.flip()

    SF_sendHTTPheader(socket, "/NORAD/elements/".. tle_filename ..".txt")


    screen.print(30, 50, "> Recibiendo archivo " .. tle_filename .. ".tle", sf_palette[4])
    screen.waitvblankstart()
    screen.flip()
    screen.print(30, 50, "> Recibiendo archivo " .. tle_filename .. ".tle ...", sf_palette[4])
    screen.waitvblankstart()
    screen.flip()


    -- Obtenemos el fichero TLE
    local f = io.open ("./tle/"..tle_filename .. ".tle", "w+")
    local buffer_len = 1
    reintentos = 20
    while (buffer_len > 0) do
        screen.waitvblankstart(5)
        local buffer = socket:recv(500)
        if string.len(buffer) > 0 then
            f:write (buffer)
            screen.waitvblankstart(5)
            screen.flip()
            screen.waitvblankstart(5)
            screen.flip()
            buffer_len = string.len(buffer)
            reintentos = 20
        else
            if reintentos > 0 then
                reintentos = reintentos - 1
                screen.waitvblankstart(10)
                screen.flip()
                screen.waitvblankstart(10)
                screen.flip()
                buffer_len = 1
            else
                buffer_len = string.len(buffer)
            end
        end

    end
    f:flush ()
    io.close (f)
    socket:close()
    screen.print(30, 50, "> Recibiendo archivo " .. tle_filename .. ".tle ... OK!", sf_palette[4])
    screen.waitvblankstart()
    screen.flip()
    screen.print(30, 50, "> Recibiendo archivo " .. tle_filename .. ".tle ... OK!", sf_palette[4])
    screen.waitvblankstart(100)
    screen.flip()

    screen.print(30, 60, "> Informacion de los satelites actualizada con exito!", sf_palette[4])
    screen.print(30, 70, "> Procesando informacion, espere por favor...", sf_palette[8])
    screen.waitvblankstart()
    screen.flip()
    screen.print(30, 60, "> Informacion de los satelites actualizada con exito!", sf_palette[4])
    screen.print(30, 70, "> Procesando informacion, espere por favor...", sf_palette[8])

    local file = io.open("update.txt", "w+")
    if file ~= nil then
        file:write(tostring(sgp_time.jtime).."\n")
        file:flush(file)
        io.close(file)
    end

    screen.waitvblankstart(300)
    screen.flip()


    wlan.term()
end

function SF_drawLineMap( lat1 , lon1 , lat2, lon2, color )
    local px1, py1 = SF_LatLonToXY(lat1, lon1)
    local px2, py2 = SF_LatLonToXY(lat2, lon2)

    draw.line( px1, py1, px2, py2, color)
end


function SF_drawBitmapMap( lat , lon , bitmap, xini, yini, xlen, ylen )

    local px, py = SF_LatLonToXY(lat, lon)
    image.blit(px - xlen/2, py - ylen/2, bitmap, xini, yini, xlen, ylen, true)
end



function SF_drawSuperPointSky( azimut , elevacion , color )
    if elevacion > sf_sky.elevacion_minima then
        local px, py = SF_AzElevToXY( azimut, elevacion )
        if px > 0 and px < screen.width()-1 and py > 0 and py < screen.height()-1 then
            image.pixel( px , py , color )
            px = px-2
            py = py-4
            screen.print(px, py, "o", color)
        end
    end
end

function SF_drawSuperCrossSky( azimut , elevacion , color )
    if elevacion > sf_sky.elevacion_minima then
        local px, py = SF_AzElevToXY( azimut, elevacion )
        if px > 0 and px < screen.width()-1 and py > 0 and py < screen.height()-1 then
            image.pixel( px , py , color )
            px = px-2
            py = py-4
            screen.print(px, py, "x", color)
        end
    end
end

function SF_drawSuperPointMap( latitud , longitud , color )
    local px, py = SF_LatLonToXY(latitud, longitud)
    image.pixel( px , py , color )
    px = px-2
    py = py-4
    screen.print(px, py, "o", color)
end

function SF_drawSuperCrossMap( latitud , longitud , color )
    local px, py = SF_LatLonToXY(latitud, longitud)
    px = px-2
    py = py-4
    screen.print(px, py, "x", color)
end

function SF_drawLabelSatsSky(azimut, elevacion, texto, color)
    if elevacion > sf_sky.elevacion_minima then
        local px, py = SF_AzElevToXY( azimut, elevacion )
        if azimut > 90 and azimut < 270 then
            screen.print(px+ 5, py-10, texto, color)
        else
            screen.print(px+ 5, py+2, texto, color)
        end
    end
end


function SF_drawSatellitesSky()
    local s
    for s = 1,sgp_sat_number do
            SF_drawSatSky( s )
    end
end

function SF_drawSatellitesMap()
    local s
    for s = 1,sgp_sat_number do
            SF_drawSatMap( s )
    end
end

function SF_decimales( valor, precision )
    local absoluto = math.abs (valor)

    return (absoluto - math.floor(absoluto))*10*precision
end

function SF_drawBackgroundInfo ()

--Sol
    draw.fillrect(0,0,236,9,sf_palette[6])
    draw.line(0,0,239,0,sf_palette[1])
    draw.line(0,9,235,9,sf_palette[10])
    draw.fillrect(0,10,236,10,sf_palette[12])
    draw.line(0,19,235,19,sf_palette[14])
    draw.line(0,39,235,39,sf_palette[14])
    draw.fillrect(0,40,236,10,sf_palette[12])
    draw.line(0,49,235,49,sf_palette[14])
    draw.line(0,59,235,59,sf_palette[14])
    draw.fillrect(0,60,236,10,sf_palette[12])
    draw.line(0,69,235,69,sf_palette[14])
--Luna
    draw.fillrect(0,100,236,10,sf_palette[6])
    draw.line(0,99,235,99,sf_palette[1])
    draw.line(0,109,235,109,sf_palette[10])
    draw.fillrect(0,110,236,10,sf_palette[12])
    draw.line(0,119,235,119,sf_palette[14])
    draw.line(0,139,235,139,sf_palette[14])
    draw.fillrect(0,140,236,10,sf_palette[12])
    draw.line(0,149,235,149,sf_palette[14])
    draw.line(0,159,235,159,sf_palette[14])
    draw.fillrect(0,160,236,10,sf_palette[12])
    draw.line(0,169,235,169,sf_palette[14])
    draw.line(0,189,215,189,sf_palette[14])
    draw.line(215,170,215,189,sf_palette[14])
    draw.fillrect(0,190,190,10,sf_palette[12])
    draw.line(190,190,190,199,sf_palette[14])
    draw.line(0,199,235,199,sf_palette[14])
    draw.fillrect(0,200,236,10,sf_palette[12])
    draw.line(0,209,235,209,sf_palette[14])
    draw.line(0,219,235,219,sf_palette[14])
    draw.fillrect(0,220,236,10,sf_palette[12])
    draw.line(0,229,235,229,sf_palette[14])

-- Separador intermedio
    draw.fillrect(236,1,3,272,sf_palette[6])

-- Situación
    draw.fillrect(239,0,241,9,sf_palette[6])
    draw.line(239,0,480,0,sf_palette[1])
    draw.line(239,9,480,9,sf_palette[10])
    draw.line(239,19,480,19,sf_palette[14])
    draw.fillrect(239,10,50,9,sf_palette[12])
    draw.line(289,10,289,19,sf_palette[14])
    draw.line(239,39,480,39,sf_palette[14])
    draw.line(239,29,307,29,sf_palette[14])
    draw.fillrect(239,20,68,9,sf_palette[12])
    draw.line(307,20,307,29,sf_palette[14])
    draw.line(239,49,480,49,sf_palette[14])
    draw.fillrect(239,40,241,9,sf_palette[12])

-- Hora y fecha
    draw.fillrect(239,80,241,9,sf_palette[6])
    draw.line(239,79,480,79,sf_palette[1])
    draw.line(239,89,480,89,sf_palette[10])

-- Satelites
    draw.fillrect(239,140,241,9,sf_palette[6])
    draw.line(239,139,480,139,sf_palette[1])
    draw.line(239,149,480,149,sf_palette[10])

-- Estrellas
    draw.fillrect(239,190,241,9,sf_palette[6])
    draw.line(239,189,480,189,sf_palette[1])
    draw.line(239,199,480,199,sf_palette[10])

-- PSP
    draw.fillrect(239,230,241,9,sf_palette[6])
    draw.line(239,229,480,229,sf_palette[1])
    draw.line(239,239,480,239,sf_palette[10])


end

function SF_drawSunInfo ()

    screen.print(1, 1,  "    SOL" , sf_palette[14])
    screen.print(1, 11, "Posicion", sf_palette[8])
    screen.print(1, 21, " Azim " .. string.format("%.3d.%.2d",sgp_sun.azi, SF_decimales( sgp_sun.azi,2)), sf_palette[4])
    screen.print(1, 31, " Elev " .. string.format ("%+.2d.%.2d",sgp_sun.ele, SF_decimales( sgp_sun.ele,2)), sf_palette[4])
    if sgp_sun.lat >= 0 then
        screen.print(113, 21, "Lat  " .. string.format ("%.2d.%.2d",sgp_sun.lat,SF_decimales(sgp_sun.lat,2)) .. " N" , sf_palette[4])
    else
        screen.print(113, 21, "Lat  " .. string.format ("%.2d.%.2d",-sgp_sun.lat,SF_decimales(sgp_sun.lat,2)) .. " S" , sf_palette[4])
    end
    if sgp_sun.lon >= 0 then
        screen.print(113, 31, "Lon " .. string.format ("%.3d.%.2d",sgp_sun.lon,SF_decimales(sgp_sun.lon,2)) .. " E", sf_palette[4])
    else
        screen.print(113, 31, "Lon " .. string.format ("%.3d.%.2d",-sgp_sun.lon,SF_decimales(sgp_sun.lon,2)) .. " W", sf_palette[4])
    end
    screen.print(1, 41, "Distancia en millones de KMs", sf_palette[8])
    screen.print(1, 51, " 142.7 < ", sf_palette[8])
    screen.print(73, 51, string.format ("%.6f",sgp_sun.alt/1000000) , sf_palette[4])
    screen.print(153, 51, " < 151.8", sf_palette[8])
    screen.print(1, 61, "Salidas y puestas de Sol" , sf_palette[8])
    if sgp_sun.ele > 0 then
        screen.print(1, 71, " Ha salido a las " .. sgp_sun.raise.hour .. ":" .. string.format ("%.2d",sgp_sun.raise.min) , sf_palette[4])
        screen.print(1, 81, " Se va poner a las " .. sgp_sun.set.hour .. ":" .. string.format ("%.2d",sgp_sun.set.min) , sf_palette[4])
    else
        screen.print(1, 71, " Se ha puesto a las " .. sgp_sun.set.hour .. ":" .. string.format ("%.2d",sgp_sun.set.min) , sf_palette[4])
        screen.print(1, 81, " Va a salir a las " .. sgp_sun.raise.hour .. ":" .. string.format ("%.2d",sgp_sun.raise.min)  , sf_palette[4])
    end
end

function SF_drawMoonInfo()
    screen.print(1, 101, "    LUNA" , sf_palette[14])
    screen.print(1, 111, "Posicion", sf_palette[8])
    screen.print(1, 121, " Azim " .. string.format("%.3d.%.2d",sgp_moon.azi, SF_decimales( sgp_moon.azi,2)), sf_palette[4])
    screen.print(1, 131, " Elev " .. string.format ("%+.2d.%.2d",sgp_moon.ele, SF_decimales( sgp_moon.ele,2)), sf_palette[4])
    if sgp_moon.lat >= 0 then
        screen.print(113, 121, "Lat  " .. string.format ("%.2d.%.2d",sgp_moon.lat,SF_decimales(sgp_moon.lat,2)) .. " N" , sf_palette[4])
    else
        screen.print(113, 121, "Lat  " .. string.format ("%.2d.%.2d",-sgp_moon.lat,SF_decimales(sgp_moon.lat,2)) .. " S" , sf_palette[4])
    end
    if sgp_moon.lon >= 0 then
        screen.print(113, 131, "Lon " .. string.format ("%.3d.%.2d",sgp_moon.lon,SF_decimales(sgp_moon.lon,2)) .. " E", sf_palette[4])
    else
        screen.print(113, 131, "Lon " .. string.format ("%.3d.%.2d",-sgp_moon.lon,SF_decimales(sgp_moon.lon,2)) .. " W", sf_palette[4])
    end
    screen.print(1, 141, "Distancia en miles de KMs", sf_palette[8])
    screen.print(1, 151, " 363.0 < ", sf_palette[8])
    screen.print(73, 151, string.format ("%.6f",sgp_moon.dist/1000) , sf_palette[4])
    screen.print(153, 151, " < 405.0", sf_palette[8])
    screen.print(1, 161, "Salidas y puestas de Luna" , sf_palette[8])
    if sgp_moon.ele > 0 then
        screen.print(1, 171, " Ha salido a las " .. sgp_moon.raise.hour.. ":" .. string.format ("%.2d",sgp_moon.raise.min) , sf_palette[4])
        screen.print(1, 181," Se va poner a las " .. sgp_moon.set.hour.. ":" .. string.format ("%.2d",sgp_moon.set.min) , sf_palette[4])
    else
        screen.print(1, 171, " Se ha puesto a las " .. sgp_moon.set.hour.. ":" .. string.format ("%.2d",sgp_moon.set.min) , sf_palette[4])
        screen.print(1, 181," Va a salir a las " .. sgp_moon.raise.hour.. ":" .. string.format ("%.2d",sgp_moon.raise.min)  , sf_palette[4])
    end
    screen.print(1, 191, "Iluminacion disco lunar", sf_palette[8])
    screen.print(185, 191, " " .. string.format ("%d", sgp_moon.phase * 100) .. "%" , sf_palette[4])
    screen.print(1, 201, "Progreso del ciclo lunar", sf_palette[8])
    screen.print(1, 211, " " .. sgp_moon.age.d .. "dias " .. sgp_moon.age.h .. "horas " .. sgp_moon.age.m .. "min (" .. string.format ("%d", sgp_moon.age.cicle * 100) .. "%)" , sf_palette[4])
    screen.print(1, 221, "Proximas fases lunares", sf_palette[8])
    local ye, mo, da, ho, mi, se = SGP_Julian_To_Date(sgp_moon.first_quarter_moon)
    screen.print(1, 231, " Creciente " .. string.format ("%.2d",da) .. "/" .. string.format ("%.2d",mo) .."/" .. ye .. " " .. string.format ("%.2d",ho) .. ":" .. string.format ("%.2d",mi), sf_palette[4])
    ye, mo, da, ho, mi, se = SGP_Julian_To_Date(sgp_moon.full_moon)
    screen.print(1, 241, " Llena     " .. string.format ("%.2d",da) .. "/" .. string.format ("%.2d",mo) .."/" .. ye .. " " .. string.format ("%.2d",ho) .. ":" .. string.format ("%.2d",mi), sf_palette[4])
    ye, mo, da, ho, mi, se = SGP_Julian_To_Date(sgp_moon.third_quarter_moon)
    screen.print(1, 251, " Menguante " .. string.format ("%.2d",da) .. "/" .. string.format ("%.2d",mo) .."/" .. ye .. " " .. string.format ("%.2d",ho) .. ":" .. string.format ("%.2d",mi), sf_palette[4])
    ye, mo, da, ho, mi, se = SGP_Julian_To_Date(sgp_moon.new_moon)
    screen.print(1, 261, " Nueva     " .. string.format ("%.2d",da) .. "/" .. string.format ("%.2d",mo) .."/" .. ye .. " " .. string.format ("%.2d",ho) .. ":" .. string.format ("%.2d",mi), sf_palette[4])
end

function SF_drawStarsInfo()
    screen.print(240, 191, "    ESTRELLAS" , sf_palette[14])
    screen.print(240, 201, "Estrellas cargadas: " , sf_palette[8])
    screen.print(400, 201, sgp_star_number , sf_palette[4])
    screen.print(240, 211, "Magnitud limite actual: " , sf_palette[8])
    screen.print(432, 211, string.format ("%.2f",sgp_mag_limit), sf_palette[4])
end

function SF_drawSatsInfo()
    screen.print(240, 141, "    SATELITES" , sf_palette[14])
    screen.print(240, 151, "Satelites cargados: " , sf_palette[8])
    screen.print(400, 151, sgp_sat_number , sf_palette[4])
    if sf_iss ~= nil then
        screen.print(240, 161, "ISS Azimut: ", sf_palette[8])
        screen.print(360, 161, string.format ("%.2f",sgp_sats[sf_iss].azimut) , sf_palette[4])
        screen.print(240, 171, "ISS Elevacion: ", sf_palette[8])
        screen.print(360, 171, string.format ("%.2f",sgp_sats[sf_iss].elevacion) , sf_palette[4])
    end
end

function SF_drawTimeInfo()
    screen.print(240, 81,  "    FECHA Y HORA" , sf_palette[14])
    screen.print(240, 91, "Local: ",sf_palette[8])
    screen.print(304, 91, sgp_time.day ..
        "/" .. sgp_time.month ..
        "/" .. sgp_time.year,sf_palette[4])
    screen.print(400, 91, sgp_time.hour ..
        ":" .. string.format("%.2d",sgp_time.min) ..
        ":" .. string.format("%.2d",sgp_time.sec), sf_palette[4])
    screen.print(240, 101, "UTC: ",sf_palette[8])
    screen.print(304, 101, sgp_time.uday ..
        "/" .. sgp_time.umonth ..
        "/" .. sgp_time.uyear,sf_palette[4])
    screen.print(400, 101, sgp_time.uhour ..
        ":" .. string.format("%.2d",sgp_time.umin) ..
        ":" .. string.format("%.2d",sgp_time.usec), sf_palette[4])
    screen.print(240, 111, "Zona horaria:" , sf_palette[8])
    screen.print(344, 111, "GMT" .. string.format ("%+03d",sgp_location.UTC_offset), sf_palette[4])
    screen.print(416, 111, "DST:" , sf_palette[8])
    if sgp_location.dst then
        screen.print(448, 111, "SI", sf_palette[4])
    else
        screen.print(448, 111, "NO", sf_palette[4])
    end

end

function SF_drawInfoBar(completa)
    if completa then
        -- Fondo de la barra (borra lo anterior)
        draw.fillrect(0, 0, 480, 9, sf_palette[14])
        draw.line(0,9, 479,9,sf_palette[10])

        -- Bateria
        local level = batt.percent()
        if level < 0 or level > 100 then
            level = "--"
        end
        screen.print(1, 1, "Bat:"..level .. "%" , sf_palette[8])

        -- Magnitud umbral
        screen.print(80, 1, "Mag:"..string.format ("%.1f",sgp_mag_limit), sf_palette[8])

        -- Fremes per second
        screen.print(160, 1, "Fps:"..string.format ("%.1f",sf_fps), sf_palette[8])

        -- Zoom
        screen.print(240, 1, "Zoom:"..string.format ("%.1fx",sf_sky.radio/241), sf_palette[8])

        -- Rotación
        screen.print(336, 1, "Rot:"..string.format ("%.1f",sf_sky.rotacion), sf_palette[8])

    else
        draw.fillrect(414, 0, 479, 9, sf_palette[14])
        draw.line(414,9, 479,9,sf_palette[10])
        draw.line(414,9, 414,0,sf_palette[10])
    end

    -- Hora actual
    SGP_getCurrentTime()
    if sgp_time.hour >= 10 then
        screen.print(416, 1, sgp_time.hour ..
            ":" .. string.format("%.2d",sgp_time.min) ..
            ":" .. string.format("%.2d",sgp_time.sec) , sf_palette[10])
    else
        screen.print(424, 1,sgp_time.hour ..
            ":" .. string.format("%.2d",sgp_time.min) ..
            ":" .. string.format("%.2d",sgp_time.sec), sf_palette[10])
    end
end

function SF_drawLocationInfo ()
    screen.print(240, 1,  "    SITUACION OBSERVADOR" , sf_palette[14])

    screen.print(240, 11, "Nombre" , sf_palette[8])
    screen.print(304, 11, sgp_location.name, sf_palette[4])
    screen.print(240, 21, "Posicion", sf_palette[8])
    if sgp_location.lat >= 0 then
        screen.print(368, 21, "Lat  " .. string.format ("%.2d.%.2d",sgp_location.lat,SF_decimales(sgp_location.lat,2)) .. " N" , sf_palette[4])
    else
        screen.print(368, 21, "Lat  " .. string.format ("%.2d.%.2d",-sgp_location.lat,SF_decimales(sgp_location.lat,2)) .. " S" , sf_palette[4])
    end
    if sgp_location.lon >= 0 then
        screen.print(368, 31, "Lon " .. string.format ("%.3d.%.2d",sgp_location.lon,SF_decimales(sgp_location.lon,2)) .. " E", sf_palette[4])
    else
        screen.print(368, 31, "Lon " .. string.format ("%.3d.%.2d",-sgp_location.lon,SF_decimales(sgp_location.lon,2)) .. " W", sf_palette[4])
    end
    screen.print(248, 31, "Alt " .. string.format("%.4d m",sgp_location.alt), sf_palette[4])
    screen.print(240, 41, "La Noche" , sf_palette[8])
    if sgp_sun.ele > const_twilightCivil then
        screen.print(240, 51, " Ha terminado a las " .. sgp_location.day.hour.. ":" .. string.format ("%.2d",sgp_location.day.min) , sf_palette[4])
        screen.print(240, 61, " Va a empezar a las " .. sgp_location.night.hour.. ":" .. string.format ("%.2d",sgp_location.night.min) , sf_palette[4])
    else
        screen.print(240, 51, " Ha empezado a las " .. sgp_location.night.hour.. ":" .. string.format ("%.2d",sgp_location.night.min) , sf_palette[4])
        screen.print(240, 61, " Va a terminar a las " .. sgp_location.day.hour.. ":" .. string.format ("%.2d",sgp_location.day.min)  , sf_palette[4])
    end
end

function SF_drawPSPInfo()
        screen.print(240, 231,  "    PSP" , sf_palette[14])
        SF_drawMemLevel(240, 241, sf_palette[4])
        SF_drawBatLevel(240, 251, sf_palette[4])
        SF_drawTempLevel(240, 261, sf_palette[4])
end


function SF_drawAllNextVisiblePassList()
    local continua_buscando = true
    local i


    if sf_next_limit == 0 then
        i = 1
        while i <= sgp_sat_number and (sf_next_limit < sf_next_max) and continua_buscando do
            screen.clear(sf_sky_color)
            draw.fillrect(0, 0, 480, 10, sf_palette[14])
            SF_drawInfoBar(false)
            screen.print( 0, 1,  " Proximos avistamientos en 30 minutos (".. string.format("%d",i/sgp_sat_number * 100) .. "%)", sf_palette[1])
            draw.line(0,9, 479,9,sf_palette[10])
            draw.fillrect(0, 10, 480, 19, sf_palette[14])
            screen.print( 0, 11, " FECHA     |INICIO     |MAXIMO     |FIN        |NOMBRE     ", sf_palette[8])
            screen.print( 0, 21, " DD/MM/AAAA|HH:MM EL AZ|HH:MM EL AZ|HH:MM EL AZ|           ", sf_palette[8])
            draw.line(0,29, 479,29,sf_palette[10])
            local j
            local limite
            if sf_next_limit > 23 then
                limite = 23
            else
                limite = sf_next_limit
            end
            for j = 1,limite do
                local c = math.floor ((90- sf_next_passes[j].max_elevacion)/90*12)
                screen.print( 8, 21 + 10*j, sf_next_passes[j].linea , sf_palette[4 + c])
            end
            draw.line(0,259, 479,259,sf_palette[10])
            draw.fillrect(0, 260, 480, 272, sf_palette[14])
            screen.print(0, 261,  " Pulsa CUADRADO para parar." , sf_palette[1])
            screen.waitvblankstart()
            screen.flip()
            screen.clear(sf_sky_color)
            draw.fillrect(0, 0, 480, 10, sf_palette[14])
            SF_drawInfoBar(false)
            screen.print( 0, 1,  " Proximos avistamientos en 30 minutos (".. string.format("%d",i/sgp_sat_number * 100) .. "%)", sf_palette[1])
            draw.line(0,9, 479,9,sf_palette[10])
            draw.fillrect(0, 10, 480, 20, sf_palette[14])
            screen.print( 0, 11, " FECHA     |INICIO     |MAXIMO     |FIN        |NOMBRE     ", sf_palette[8])
            screen.print( 0, 21, " DD/MM/AAAA|HH:MM EL AZ|HH:MM EL AZ|HH:MM EL AZ|           ", sf_palette[8])
            draw.line(0,29, 479,29,sf_palette[10])
            for j = 1,limite do
                local c = math.floor ((90- sf_next_passes[j].max_elevacion)/90*12)
                screen.print( 8, 21 + 10*j, sf_next_passes[j].linea , sf_palette[4 + c])
            end
            draw.line(0,259, 479,259,sf_palette[10])
            draw.fillrect(0, 260, 480, 272, sf_palette[14])
            screen.print(0, 261,  " Pulsa CUADRADO para parar." , sf_palette[1])
            screen.waitvblankstart()
            screen.flip()
            continua_buscando = SGP_calculateAllNextVisiblePass(i)

            i = i + 1
        end
        if sf_next_current > 23 then
            sf_next_current = 23
        end
    end

    while true do
        screen.clear(sf_sky_color)
        draw.fillrect(0, 0, 480, 10, sf_palette[14])
        SF_drawInfoBar(false)
        screen.print( 0, 1,  " Proximos avistamientos en 30 minutos", sf_palette[1])
        draw.line(0,9, 479,9,sf_palette[10])
        draw.fillrect(0, 10, 480, 20, sf_palette[14])
        screen.print( 0, 11, " FECHA     |INICIO     |MAXIMO     |FIN        |NOMBRE     ", sf_palette[8])
        screen.print( 0, 21, " DD/MM/AAAA|HH:MM EL AZ|HH:MM EL AZ|HH:MM EL AZ|           ", sf_palette[8])
        draw.line(0,29, 479,29,sf_palette[10])

        local i
        local limite
        if sf_next_limit > 23 then
            limite = 23
        else
            limite = sf_next_limit
        end
        if limite == 0 then
            screen.print( 8, 21 + 10*1, "Ningun satelite va a ser visible en 30 minutos." , sf_palette[8])
            screen.print( 8, 21 + 10*2, "Intentelo otra vez mas tarde." , sf_palette[8])

        else
            for i = 1,limite do
                if sf_next_current == i then
                    screen.print( 0, 21 + 10*i, ">"..sf_next_passes[i].linea , sf_palette[1])
                else
                    local c = math.floor ((90- sf_next_passes[i].max_elevacion)/90*12)
                    screen.print( 8, 21 + 10*i, sf_next_passes[i].linea , sf_palette[4 + c])
                end
            end
        end
        draw.line(0,259, 479,259,sf_palette[10])
        draw.fillrect(0, 260, 480, 272, sf_palette[14])
        screen.print(0, 261, " Pulsa X para seleccionar. Pulsa O para buscar otra vez." , sf_palette[1])
        screen.waitvblankstart()
        screen.flip()


        sf_entrada = Controls.read()


        if sf_entrada:down() then
            if sf_next_current < limite then
                sf_next_current = sf_next_current + 1
            end
        elseif sf_entrada:up() then
            if sf_next_current > 1 then
                sf_next_current = sf_next_current - 1
            end
        elseif sf_entrada ~= sf_entrada_ant then
            sf_entrada_ant = sf_entrada
            if sf_entrada:cross() then
                if sf_next_current > 0 then
                    sf_selected_sat = sf_next_passes[sf_next_current].sat
                    SF_generateNextPassPathSky(sf_selected_sat)

                end
                return
            end
            if sf_entrada:circle() then
                sf_next_limit = 0
                sf_next_current = 0
                SF_drawAllNextVisiblePassList()
                return
            end
            if sf_entrada:r() and sf_entrada:l() then
                SF_screenshot()
            end
        end

        sf_entrada_ant = sf_entrada
        screen.waitvblankstart(5)
    end
end

function SF_drawSatNextVisiblePassList(sat)
    local continua_buscando = true
    screen.clear(sf_sky_color)
    draw.fillrect(0, 0, 480, 10, sf_palette[14])
    SF_drawInfoBar(false)
    screen.waitvblankstart()
    screen.flip()
    screen.clear(sf_sky_color)
    draw.fillrect(0, 0, 480, 10, sf_palette[14])
    SF_drawInfoBar(false)
    screen.waitvblankstart()
    screen.flip()
    SF_drawInfoBar(false)
    screen.print( 0, 1,  " Proximos avistamientos del satelite "..sgp_sats[sat].nombre, sf_palette[1])
    draw.line(0,9, 479,9,sf_palette[10])
    draw.fillrect(0, 10, 480, 19, sf_palette[14])
    screen.print( 0, 11, " FECHA     | INICIO     | MAXIMO     | FIN                 ", sf_palette[1])
    screen.print( 0, 21, " DD/MM/AAAA| HH:MM EL AZ| HH:MM EL AZ| HH:MM EL AZ         ", sf_palette[1])
    draw.line(0,29, 479,29,sf_palette[10])
    local i
    for i = 1,sf_pass_limit do
        if sf_pass_current == i then
            screen.print( 8, 21 + 10*i, sf_passes[i].linea , sf_palette[4])
        else
            local c = math.floor ((90- sf_passes[i].max_elevacion)/90*12)
            screen.print( 8, 21 + 10*i, sf_passes[i].linea , sf_palette[4 + c])
        end
    end
    draw.line(0,259, 479,259,sf_palette[10])
    draw.fillrect(0, 260, 480, 272, sf_palette[14])
    screen.waitvblankstart()
    screen.flip()
    SF_drawInfoBar(false)
    screen.print( 0, 1,  " Proximos avistamientos del satelite "..sgp_sats[sat].nombre, sf_palette[1])
    draw.line(0,9, 479,9,sf_palette[10])
    draw.fillrect(0, 10, 480, 19, sf_palette[14])
    screen.print( 0, 11, " FECHA     | INICIO     | MAXIMO     | FIN                 ", sf_palette[1])
    screen.print( 0, 21, " DD/MM/AAAA| HH:MM EL AZ| HH:MM EL AZ| HH:MM EL AZ         ", sf_palette[1])
    draw.line(0,29, 479,29,sf_palette[10])
    for i = 1,sf_pass_limit do
        if sf_pass_current == i then
            screen.print( 8, 21 + 10*i, sf_passes[i].linea , sf_palette[4])
        else
            local c = math.floor ((90- sf_passes[i].max_elevacion)/90*12)
            screen.print( 8, 21 + 10*i, sf_passes[i].linea , sf_palette[4 + c])
        end
    end
    draw.line(0,259, 479,259,sf_palette[10])
    draw.fillrect(0, 260, 480, 272, sf_palette[14])
    screen.waitvblankstart()
    screen.flip()
    screen.print(0, 261,  " Pulsa CUADRADO para parar." , sf_palette[1])
    screen.waitvblankstart()
    screen.flip()
    screen.print(0, 261,  " Pulsa CUADRADO para parar." , sf_palette[1])
    screen.waitvblankstart()
    screen.flip()
    while (sf_pass_limit < sf_pass_max) and continua_buscando do
        continua_buscando = SGP_calculateSatNextVisiblePass(sat)

    end

    while true do
        screen.clear(sf_sky_color)
        draw.fillrect(0, 0, 480, 10, sf_palette[14])
        SF_drawInfoBar(false)
        screen.print( 0, 1,  " Proximos avistamientos del satelite "..sgp_sats[sat].nombre, sf_palette[1])
        draw.line(0,9, 479,9,sf_palette[10])
        draw.fillrect(0, 10, 480, 19, sf_palette[14])
        screen.print( 0, 11, " FECHA     | INICIO     | MAXIMO     | FIN                 ", sf_palette[1])
        screen.print( 0, 21, " DD/MM/AAAA| HH:MM EL AZ| HH:MM EL AZ| HH:MM EL AZ         ", sf_palette[1])
        draw.line(0,29, 479,29,sf_palette[10])

        local i
        for i = 1,sf_pass_limit do
            if sf_pass_current == i then
                screen.print( 0, 21 + 10*i, ">" .. sf_passes[i].linea , sf_palette[1])
            else
                local c = math.floor ((90- sf_passes[i].max_elevacion)/90*12)
                screen.print( 8, 21 + 10*i, sf_passes[i].linea , sf_palette[4 + c])
            end
        end
        draw.line(0,259, 479,259,sf_palette[10])
        draw.fillrect(0, 260, 480, 272, sf_palette[14])
        screen.print(0, 261,  " Pulsa X para seleccionar la que quiera ver marcada." , sf_palette[1])
        screen.waitvblankstart()
        screen.flip()


        sf_entrada = Controls.read()


        if sf_entrada:down() then
            if sf_pass_current < sf_pass_limit then
                sf_pass_current = sf_pass_current + 1
            end
        elseif sf_entrada:up() then
            if sf_pass_current > 1 then
                sf_pass_current = sf_pass_current - 1
            end
        elseif sf_entrada ~= sf_entrada_ant then
            sf_entrada_ant = sf_entrada
            if sf_entrada:cross() then
                sf_selected_sat = sat
                SF_generatePassPathSky(sat)
                return
            end
            if sf_entrada:r() and sf_entrada:l() then
                SF_screenshot()
            end
        end

        sf_entrada_ant = sf_entrada

        screen.waitvblankstart(10)
    end

end

function SGP_calculateAllNextVisiblePass(s)
    local jtime


    SGP_getCurrentTime()
    jtime = sgp_time.ujtime


    sf_next_limit = sf_next_limit + 1
    sf_next_current = sf_next_limit


    SGP_calculateSun (jtime)
    SGP_calculateSatellite (s , jtime)

    -- buscamos la proxima vez que estará visible y por encima del horizonte en un plazo de 1 hora
    -- incrementamos mucho cuando su elevacion baja y poco cuando sube
    local sf_mostrar_progreso = 0
    local one_hour_after = jtime + const_julian_minute * 30
    while not ( sgp_sats[s].elevacion > sf_sky.elevacion_minima and sgp_sats[s].visible) do
        if sgp_sats[s].elevacion > sgp_sats[s].elevacion_ant and sgp_sun.ele < 15 then
            jtime = jtime + const_julian_minute * sf_next_visible_precision
        else
            jtime = jtime + const_julian_minute * sf_next_visible_precision * 50
        end


        if jtime >= one_hour_after then
            --lo dejamos todo como estaba (en el tiempo real), incluso la dirección, llamando dos veces
            SGP_calculateSun (sgp_time.ujtime - const_julian_minute)
            SGP_calculateSatellite (s , sgp_time.ujtime - const_julian_minute)
            SGP_calculateSun (sgp_time.ujtime)
            SGP_calculateSatellite (s , sgp_time.ujtime)
            SF_erase(1, 21+sf_next_limit*10, 60)
            sf_next_limit = sf_next_limit - 1
            sf_next_current = sf_next_limit
            screen.waitvblankstart()
            screen.flip()
            return true
        end


        SGP_calculateSun (jtime)
        SGP_calculateSatellite (s , jtime)
        if sf_mostrar_progreso <= 0 then
            sf_mostrar_progreso = 15

            local jt_temp = SGP_UTC_to_Local(jtime)
            local year , month, day, hour, minute, second = SGP_Julian_To_Date(jt_temp)

            SF_drawInfoBar(false)

            if sf_next_current <= 22 then
                SF_erase(8, 21+sf_next_limit*10, 60)
                screen.print(8, 21+sf_next_limit*10, string.format ("%02d",day) .. "/" .. string.format ("%02d",month)
                .. "/" .. year .. " " .. string.format ("%02d",hour) .. ":" .. string.format("%02d",minute)..
                "                               " .. sgp_sats[s].nombre, sf_palette[12])
                screen.waitvblankstart()
                screen.flip()
            end

            sf_entrada = Controls.read()

            if sf_entrada ~= sf_entrada_ant then
                sf_entrada_ant = sf_entrada
                if sf_entrada:square() then
                    --lo dejamos todo como estaba (en el tiempo real), incluso la dirección, llamando dos veces
                    SGP_calculateSun (sgp_time.ujtime - const_julian_minute)
                    SGP_calculateSatellite (s , sgp_time.ujtime - const_julian_minute)
                    SGP_calculateSun (sgp_time.ujtime)
                    SGP_calculateSatellite (s , sgp_time.ujtime)
                    SF_erase(1, 21+sf_next_limit*10, 60)
                    sf_next_limit = sf_next_limit - 1
                    sf_next_current = sf_next_limit
                    screen.waitvblankstart()
                    screen.flip()

                    return false
                end
            end
            sf_entrada_ant = sf_entrada
        else
            sf_mostrar_progreso = sf_mostrar_progreso - 1
        end
    end


    -- una vez encontrado un punto donde el satelite es visible por encima de la elevación minima establecida
    -- buscamos el inicio de este hecho retrocediendo en saltitos pequeños

    repeat
        jtime = jtime - const_julian_minute * sf_next_visible_precision * 0.2
        SGP_calculateSun (jtime)
        SGP_calculateSatellite (s , jtime)

    until ( not sgp_sats[s].visible or sgp_sats[s].elevacion <= sf_sky.elevacion_minima)

    --hemos encontrado cuando empieza a ser visible. Lo apuntamos.
    jtime = jtime + const_julian_minute * sf_next_visible_precision * 0.2
    SGP_calculateSun (jtime)
    SGP_calculateSatellite (s , jtime)


    sgp_sats[s].no_calcular = 0

    local temp_jt =  SGP_UTC_to_Local(jtime)
    local temp_ele = sgp_sats[s].elevacion
    local temp_azi = sgp_sats[s].azimut

    --Ahora vamos a ver la elevación maxima visible que va a tener avanzando en saltos pequeños

    repeat
        jtime = jtime + const_julian_minute * sf_next_visible_precision * 0.2
        SGP_calculateSun (jtime)
        SGP_calculateSatellite (s , jtime)
    until ( (sgp_sats[s].elevacion < sgp_sats[s].elevacion_ant) or (not sgp_sats[s].visible) or (sgp_sats[s].elevacion < sf_sky.elevacion_minima))

    jtime = jtime - const_julian_minute * sf_next_visible_precision * 0.2
    SGP_calculateSun (jtime)
    SGP_calculateSatellite (s , jtime)


    local j = 1
    local momento = SGP_UTC_to_Local(jtime)
    while j < sf_next_limit and sf_next_passes[j].max_jt < momento do
        j = j + 1
    end

    if (j < sf_next_limit) then
        local k = sf_next_limit-1

        while k >= j do
            sf_next_passes[k+1].ini_jt = sf_next_passes[k].ini_jt
            sf_next_passes[k+1].max_jt = sf_next_passes[k].max_jt
            sf_next_passes[k+1].fin_jt = sf_next_passes[k].fin_jt
            sf_next_passes[k+1].ini_azimut = sf_next_passes[k].ini_azimut
            sf_next_passes[k+1].max_azimut = sf_next_passes[k].max_azimut
            sf_next_passes[k+1].fin_azimut = sf_next_passes[k].fin_azimut
            sf_next_passes[k+1].ini_elevacion = sf_next_passes[k].ini_elevacion
            sf_next_passes[k+1].max_elevacion = sf_next_passes[k].max_elevacion
            sf_next_passes[k+1].fin_elevacion = sf_next_passes[k].fin_elevacion
            sf_next_passes[k+1].linea = sf_next_passes[k].linea
            sf_next_passes[k+1].sat = sf_next_passes[k].sat
            k = k - 1
        end



        sf_next_current = j


    end
    sf_next_passes[sf_next_current].ini_jt = temp_jt
    sf_next_passes[sf_next_current].ini_elevacion = temp_ele
    sf_next_passes[sf_next_current].ini_azimut = temp_azi

    --apuntamos la elevacion maxima visible y ya que estamos el azimut
    sf_next_passes[sf_next_current].max_jt = SGP_UTC_to_Local(jtime)
    sf_next_passes[sf_next_current].max_elevacion = sgp_sats[s].elevacion
    sf_next_passes[sf_next_current].max_azimut = sgp_sats[s].azimut

    --Ahora vamos a ver donde termina de ser visible

    repeat
        jtime = jtime + const_julian_minute * sf_next_visible_precision * 0.2
        SGP_calculateSun (jtime)
        SGP_calculateSatellite (s , jtime)
    until ( (not sgp_sats[s].visible) or (sgp_sats[s].elevacion < sf_sky.elevacion_minima))

    jtime = jtime - const_julian_minute * sf_next_visible_precision * 0.2
    SGP_calculateSun (jtime)
    SGP_calculateSatellite (s , jtime)

    --apuntamos donde termina de verse
    sf_next_passes[sf_next_current].fin_jt = SGP_UTC_to_Local(jtime)
    sf_next_passes[sf_next_current].fin_elevacion = sgp_sats[s].elevacion
    sf_next_passes[sf_next_current].fin_azimut = sgp_sats[s].azimut

    sf_next_passes[sf_next_current].sat = s

    --lo dejamos todo como estaba (en el tiempo real), incluso la dirección, llamando dos veces
    SGP_calculateSun (sgp_time.ujtime - const_julian_minute)
    SGP_calculateSatellite (s , sgp_time.ujtime - const_julian_minute)
    SGP_calculateSun (sgp_time.ujtime)
    SGP_calculateSatellite (s , sgp_time.ujtime)

    local year, month, day, hour, minute, second = SGP_Julian_To_Date(sf_next_passes[sf_next_current].ini_jt)
    sf_next_passes[sf_next_current].linea = string.format ("%02d",day) .. "/" .. string.format ("%02d",month)
    .. "/" .. year .. " " .. string.format ("%02d",hour) .. ":" .. string.format("%02d",minute)
    .. " " .. string.format("%02d", sf_next_passes[sf_next_current].ini_elevacion) .. " "
    .. SF_azimutToString(sf_next_passes[sf_next_current].ini_azimut) .. " "

    year, month, day, hour, minute, second = SGP_Julian_To_Date(sf_next_passes[sf_next_current].max_jt)
    sf_next_passes[sf_next_current].linea = sf_next_passes[sf_next_current].linea
    .. string.format ("%02d",hour) .. ":" .. string.format("%02d",minute)
    .. " " .. string.format("%02d", sf_next_passes[sf_next_current].max_elevacion) .. " "
    .. SF_azimutToString(sf_next_passes[sf_next_current].max_azimut) .. " "

    year, month, day, hour, minute, second = SGP_Julian_To_Date(sf_next_passes[sf_next_current].fin_jt)
    sf_next_passes[sf_next_current].linea = sf_next_passes[sf_next_current].linea
    .. string.format ("%02d",hour) .. ":" .. string.format("%02d",minute)
    .. " " .. string.format("%02d", sf_next_passes[sf_next_current].fin_elevacion) .. " "
    .. SF_azimutToString(sf_next_passes[sf_next_current].fin_azimut) .. " " .. sgp_sats[s].nombre

    return true

end

function SGP_calculateSatNextVisiblePass(s)
    local entrada

    local jtime

    if sf_pass_limit == 0 then
        SGP_getCurrentTime()
        jtime = sgp_time.ujtime
    else
        jtime = sf_passes[sf_pass_limit].fin_jt + const_julian_minute * 20
    end

    sf_pass_limit = sf_pass_limit + 1
    sf_pass_current = sf_pass_limit
    -- no sabemos donde se encuentra ahora mismo el satélite, pero no queremos
    -- que se encuentre a la vista, asi que si es así, lo metemos en el horizonte
    -- con saltos grandes de 15 minutos
    SGP_calculateSun (jtime)
    SGP_calculateSatellite (s , jtime)

    -- buscamos la proxima vez que estará visible y por encima del horizonte.
    -- incrementamos mucho cuando su elevacion baja y poco cuando sube
    local sf_mostrar_progreso = 0
    while not ( sgp_sats[s].elevacion > sf_sky.elevacion_minima and sgp_sats[s].visible ) do

        if sgp_sats[s].elevacion > sgp_sats[s].elevacion_ant and sgp_sun.ele < 15 then
            jtime = jtime + const_julian_minute * sf_next_visible_precision
        else
            jtime = jtime + const_julian_minute * sf_next_visible_precision * 50
        end
        SGP_calculateSun (jtime)
        SGP_calculateSatellite (s , jtime)
        if sf_mostrar_progreso <= 0 then
            sf_mostrar_progreso = 15

            local jt_temp = SGP_UTC_to_Local(jtime)
            local year , month, day, hour, minute, second = SGP_Julian_To_Date(jt_temp)

            SF_drawInfoBar(false)

            SF_erase(8, 21+sf_pass_limit*10, 60)
            screen.print(8, 21+sf_pass_limit*10, string.format ("%02d",day) .. "/" .. string.format ("%02d",month)
            .. "/" .. year .. "  " .. string.format ("%02d",hour) .. ":" .. string.format("%02d",minute), sf_palette[12])
            screen.waitvblankstart()
            screen.flip()
            entrada = Controls.read()

            if entrada:square() then
                --lo dejamos todo como estaba (en el tiempo real), incluso la dirección, llamando dos veces
                SGP_calculateSun (sgp_time.ujtime - const_julian_minute)
                SGP_calculateSatellite (s , sgp_time.ujtime - const_julian_minute)
                SGP_calculateSun (sgp_time.ujtime)
                SGP_calculateSatellite (s , sgp_time.ujtime)
                sf_pass_limit = sf_pass_limit - 1
                sf_pass_current = sf_pass_limit
                SF_erase(1, 20+sf_pass_limit*10, 60)
                screen.waitvblankstart()
                screen.flip()

                return false
            end
        else
            sf_mostrar_progreso = sf_mostrar_progreso - 1
        end
    end

    -- una vez encontrado un punto donde el satelite es visible por encima de la elevación minima establecida
    -- buscamos el inicio de este hecho retrocediendo en saltitos pequeños

    repeat
        jtime = jtime - const_julian_minute * sf_next_visible_precision * 0.2
        SGP_calculateSun (jtime)
        SGP_calculateSatellite (s , jtime)

    until ( not sgp_sats[s].visible or sgp_sats[s].elevacion <= sf_sky.elevacion_minima)

    --hemos encontrado cuando empieza a ser visible. Lo apuntamos.
    jtime = jtime + const_julian_minute * sf_next_visible_precision * 0.2
    SGP_calculateSun (jtime)
    SGP_calculateSatellite (s , jtime)

    sf_passes[sf_pass_current].ini_jt = SGP_UTC_to_Local(jtime)
    sf_passes[sf_pass_current].ini_elevacion = sgp_sats[s].elevacion
    sf_passes[sf_pass_current].ini_azimut = sgp_sats[s].azimut

    --Ahora vamos a ver la elevación maxima visible que va a tener avanzando en saltos pequeños

    repeat
        jtime = jtime + const_julian_minute * sf_next_visible_precision * 0.2
        SGP_calculateSun (jtime)
        SGP_calculateSatellite (s , jtime)
    until ( (sgp_sats[s].elevacion < sgp_sats[s].elevacion_ant) or (not sgp_sats[s].visible) or (sgp_sats[s].elevacion < sf_sky.elevacion_minima))

    jtime = jtime - const_julian_minute * sf_next_visible_precision * 0.2
    SGP_calculateSun (jtime)
    SGP_calculateSatellite (s , jtime)

    --apuntamos la elevacion maxima visible y ya que estamos el azimut
    sf_passes[sf_pass_current].max_jt = SGP_UTC_to_Local(jtime)
    sf_passes[sf_pass_current].max_elevacion = sgp_sats[s].elevacion
    sf_passes[sf_pass_current].max_azimut = sgp_sats[s].azimut

    --Ahora vamos a ver donde termina de ser visible

    repeat
        jtime = jtime + const_julian_minute * sf_next_visible_precision * 0.2
        SGP_calculateSun (jtime)
        SGP_calculateSatellite (s , jtime)
    until ( (not sgp_sats[s].visible) or (sgp_sats[s].elevacion < sf_sky.elevacion_minima))

    jtime = jtime - const_julian_minute * sf_next_visible_precision * 0.2
    SGP_calculateSun (jtime)
    SGP_calculateSatellite (s , jtime)

    --apuntamos donde termina de verse
    sf_passes[sf_pass_current].fin_jt = SGP_UTC_to_Local(jtime)
    sf_passes[sf_pass_current].fin_elevacion = sgp_sats[s].elevacion
    sf_passes[sf_pass_current].fin_azimut = sgp_sats[s].azimut



    --lo dejamos todo como estaba (en el tiempo real), incluso la dirección, llamando dos veces
    SGP_calculateSun (sgp_time.ujtime - const_julian_minute)
    SGP_calculateSatellite (s , sgp_time.ujtime - const_julian_minute)
    SGP_calculateSun (sgp_time.ujtime)
    SGP_calculateSatellite (s , sgp_time.ujtime)

    local year, month, day, hour, minute, second = SGP_Julian_To_Date(sf_passes[sf_pass_current].ini_jt)
    sf_passes[sf_pass_current].linea = string.format ("%02d",day) .. "/" .. string.format ("%02d",month)
    .. "/" .. year .. "  " .. string.format ("%02d",hour) .. ":" .. string.format("%02d",minute)
    .. " " .. string.format("%02d", sf_passes[sf_pass_current].ini_elevacion) .. " "
    .. SF_azimutToString(sf_passes[sf_pass_current].ini_azimut) .. "  "

    year, month, day, hour, minute, second = SGP_Julian_To_Date(sf_passes[sf_pass_current].max_jt)
    sf_passes[sf_pass_current].linea = sf_passes[sf_pass_current].linea
    .. string.format ("%02d",hour) .. ":" .. string.format("%02d",minute)
    .. " " .. string.format("%02d", sf_passes[sf_pass_current].max_elevacion) .. " "
    .. SF_azimutToString(sf_passes[sf_pass_current].max_azimut) .. "  "

    year, month, day, hour, minute, second = SGP_Julian_To_Date(sf_passes[sf_pass_current].fin_jt)
    sf_passes[sf_pass_current].linea = sf_passes[sf_pass_current].linea
    .. string.format ("%02d",hour) .. ":" .. string.format("%02d",minute)
    .. " " .. string.format("%02d", sf_passes[sf_pass_current].fin_elevacion) .. " "
    .. SF_azimutToString(sf_passes[sf_pass_current].fin_azimut)

    local c = math.floor ((90- sf_passes[sf_pass_current].max_elevacion)/90*12)
    SF_erase(8, 21+sf_pass_limit*10, 60)
    screen.print(8, 21+sf_pass_limit*10, sf_passes[sf_pass_current].linea , sf_palette[4+c])
    screen.waitvblankstart()
    screen.flip()
    SF_erase(8, 21+sf_pass_limit*10, 60)
    screen.print(8, 21+sf_pass_limit*10, sf_passes[sf_pass_current].linea , sf_palette[4+c])
    screen.waitvblankstart()
    screen.flip()

    return true
end


function SF_generatePassPathSky(num_sat)
    if sf_pass_current < 1 or sf_pass_current > sf_pass_limit then
        return
    end

    local jtime = SGP_Local_to_UTC(sf_passes[sf_pass_current].ini_jt)
    local jtime_fin = SGP_Local_to_UTC(sf_passes[sf_pass_current].fin_jt)
    local i = 0
    while jtime < jtime_fin and i < sf_pass_path.max do
        i = i + 1
        SGP_calculateSun (jtime)
        SGP_calculateSatellite (num_sat , jtime)

        sf_pass_path[i].azimut = sgp_sats[num_sat].azimut
        sf_pass_path[i].elevacion = sgp_sats[num_sat].elevacion

        sf_pass_path[i].latitud = sgp_sats[num_sat].latitud
        sf_pass_path[i].longitud = sgp_sats[num_sat].longitud

        jtime = jtime + const_julian_minute * 0.5
    end
    sf_pass_path.longitud = i


    SGP_getCurrentTime()
    jtime = sgp_time.ujtime
    SGP_calculateSun (jtime-const_julian_minute)
    SGP_calculateSatellite (num_sat , jtime-const_julian_minute)
    SGP_calculateSun (jtime)
    SGP_calculateSatellite (num_sat , jtime)
end

function SF_generateNextPassPathSky(num_sat)
    if sf_next_current < 1 or sf_next_current > sf_next_limit then
        return
    end

    local jtime = SGP_Local_to_UTC(sf_next_passes[sf_next_current].ini_jt)
    local jtime_fin = SGP_Local_to_UTC(sf_next_passes[sf_next_current].fin_jt)
    local i = 0
    while jtime < jtime_fin and i < sf_pass_path.max do
        i = i + 1
        SGP_calculateSun (jtime)
        SGP_calculateSatellite (num_sat , jtime)

        sf_pass_path[i].azimut = sgp_sats[num_sat].azimut
        sf_pass_path[i].elevacion = sgp_sats[num_sat].elevacion

        sf_pass_path[i].latitud = sgp_sats[num_sat].latitud
        sf_pass_path[i].longitud = sgp_sats[num_sat].longitud


        jtime = jtime + const_julian_minute * 0.5
    end
    sf_pass_path.longitud = i


    SGP_getCurrentTime()
    jtime = sgp_time.ujtime
    SGP_calculateSun (jtime-const_julian_minute)
    SGP_calculateSatellite (num_sat , jtime-const_julian_minute)
    SGP_calculateSun (jtime)
    SGP_calculateSatellite (num_sat , jtime)
end

function SF_drawSatPathSky()
    local i
    if sf_pass_path.longitud <= 0 then
        return
    end

    for i = 1, sf_pass_path.longitud do
        SF_drawPointSky (sf_pass_path[i].azimut,sf_pass_path[i].elevacion,sf_palette[8])
    end
end

function SF_drawSatPathMap()
    local i
    if sf_pass_path.longitud <= 0 then
        return
    end

    for i = 1, sf_pass_path.longitud do
        SF_drawPointMap (sf_pass_path[i].latitud,sf_pass_path[i].longitud,sf_color_white)
    end
end


function SF_drawBatLevel(x, y, color_fuente)
    local level = batt.percent()
    local life = batt.time()
    local horas, minutos
    if level < 0 or level > 100 then
        level = "--"
    end

    if life < 0 or (life/60) > 20 then
        horas = "--"
        minutos = "--"

        color = color_fuente
    else

        horas = string.format ("%.0f",life / 60)
        minutos = string.format ("%.2d",life % 60)

        if sf_vision_nocturna then
            color = color_fuente
        else
            if level < 50 then
                color = color.new(255,255 * level/50,0)
            else
                color = color.new(255*(1-((level-50)/50)),255,0)
            end
        end

    end
    screen.print(x, y, "Autonomia: " .. horas.. "h " .. minutos .. "' ".. " Carga: " .. level .. "%" , color)


end

function SF_drawTempLevel(x, y,color_fuente)
    local level = batt.temp()
    local color
    if level > -20 and level < 90 then
        color = color_fuente
        if not sf_vision_nocturna then
            if level < 30 then
                color = color.new(0,255,0)
            elseif level < 40 then
                color = color.new(255*((level-30)/10),255,0)
            elseif level < 50 then
                color = color.new(255,255*(1-((level-40)/10)),0)
            else
                color = color.new(255,0,0)
            end
        end
    else
        color = color_fuente
        level = "--"
    end

    screen.print(x, y, "Temperatura bateria: " .. level .. " C"  , color)
end

function SF_drawMemLevel(x, y,color_fuente)
    --local kbytes = System.getFreeMemory()/1024
    local kbytes = gcinfo ()
    local color = color_fuente
    if not sf_vision_nocturna then
        if kbytes < 3000 then
            color = color.new(0,255,0)
        elseif kbytes < 4000 then
            color = color.new(255,255,0)
        else
            color = color.new(255,0,0)
        end
    end

    screen.print(x, y, "Memoria ocupada: " .. tostring(kbytes) .. " KB", color)
end


function SF_drawCrossSky(azimut, elevacion)
    if elevacion > 0 then
        screen.waitvblankstart()
        screen.flip()
        SF_drawBitmapSky(azimut, elevacion , bitmap_cruz,0,0,bitmap_cruz:width(),bitmap_cruz:height())
        screen.waitvblankstart()
        screen.flip()
    end
end

function SF_drawSatSky( num_sat )
    if sgp_sats[num_sat].no_calcular > 0 then
        return
    end

    if (sgp_sats[num_sat].elevacion > sf_sky.elevacion_minima) then
        if sgp_sats[num_sat].visible then
            SF_drawLineSky(sgp_sats[num_sat].azimut, sgp_sats[num_sat].elevacion, sf_sat_tails[num_sat][1].azimut, sf_sat_tails[num_sat][1].elevacion, sf_palette[1])
            if string.sub(sgp_sats[num_sat].nombre,1,7) == "IRIDIUM" then
                SF_drawSuperCrossSky(sgp_sats[num_sat].azimut, sgp_sats[num_sat].elevacion,sf_palette[1])
            else
                SF_drawSuperPointSky(sgp_sats[num_sat].azimut, sgp_sats[num_sat].elevacion,sf_palette[1])
            end
            if sf_sky.show.satelliteNames then
                SF_drawLabelSatsSky(sgp_sats[num_sat].azimut , sgp_sats[num_sat].elevacion , sgp_sats[num_sat].nombre, sf_palette[1])
            end
        else
            SF_drawLineSky(sgp_sats[num_sat].azimut, sgp_sats[num_sat].elevacion, sf_sat_tails[num_sat][1].azimut, sf_sat_tails[num_sat][1].elevacion, sf_palette[12])
            if string.sub(sgp_sats[num_sat].nombre,1,7) == "IRIDIUM" then
                SF_drawSuperCrossSky(sgp_sats[num_sat].azimut, sgp_sats[num_sat].elevacion,sf_palette[12])
            else
                SF_drawSuperPointSky(sgp_sats[num_sat].azimut, sgp_sats[num_sat].elevacion,sf_palette[12])
            end
            if sf_sky.show.satelliteNames then
                SF_drawLabelSatsSky(sgp_sats[num_sat].azimut , sgp_sats[num_sat].elevacion , sgp_sats[num_sat].nombre, sf_palette[12])
            end
        end
        if not sf_moving_sky then
            for i = 1, sf_tail_length-1 do
                if sf_sat_tails[num_sat][i].eclipsado then
                    SF_drawLineSky(sf_sat_tails[num_sat][i].azimut, sf_sat_tails[num_sat][i].elevacion, sf_sat_tails[num_sat][i+1].azimut, sf_sat_tails[num_sat][i+1].elevacion, sf_palette[math.floor(12+(i/4))])
                else
                    SF_drawLineSky(sf_sat_tails[num_sat][i].azimut, sf_sat_tails[num_sat][i].elevacion, sf_sat_tails[num_sat][i+1].azimut, sf_sat_tails[num_sat][i+1].elevacion, sf_palette[i])
                end
            end
        end
        sf_sat_tails[num_sat].step_current = sf_sat_tails[num_sat].step_current + 1
        if sf_sat_tails[num_sat].step_current >= sf_step_length then
            sf_sat_tails[num_sat].step_current = 0
            SF_AddPointToTail( num_sat, sgp_sats[num_sat].azimut, sgp_sats[num_sat].elevacion,sgp_sats[num_sat].eclipsado)
        end
    else
        if sgp_sats[num_sat].elevacion < 0 and sgp_sats[num_sat].elevacion_ant > 0 then
            SF_resetTail(num_sat)
        end
    end
end



function SF_drawMap ()
    --Polo Norte
    local fronterasX = {}
    local fronterasY = {}
    local color_fronteras
    if sf_vision_nocturna then
        color_fronteras = sf_palette[8]
    else
        color_fronteras = sf_palette[8]
    end

    fronterasX[1] = 19  fronterasY[1] = 38
    fronterasX[2] = 30  fronterasY[2] = 37
    fronterasX[3] = 41  fronterasY[3] = 38
    fronterasX[4] = 43  fronterasY[4] = 39
    fronterasX[5] = 49  fronterasY[5] = 36
    fronterasX[6] = 63  fronterasY[6] = 36
    fronterasX[7] = 80  fronterasY[7] = 35
    fronterasX[8] = 91  fronterasY[8] = 34
    fronterasX[9] = 102  fronterasY[9] = 31
    fronterasX[10] = 105  fronterasY[10] = 27
    fronterasX[11] = 100  fronterasY[11] = 27
    fronterasX[12] = 99  fronterasY[12] = 26
    fronterasX[13] = 107  fronterasY[13] = 25
    fronterasX[14] = 125  fronterasY[14] = 25
    fronterasX[15] = 138  fronterasY[15] = 23
    fronterasX[16] = 154  fronterasY[16] = 21
    fronterasX[17] = 171  fronterasY[17] = 19
    fronterasX[18] = 190  fronterasY[18] = 17
    fronterasX[19] = 201  fronterasY[19] = 16
    fronterasX[20] = 231  fronterasY[20] = 15
    fronterasX[21] = 235  fronterasY[21] = 17
    fronterasX[22] = 244  fronterasY[22] = 17
    fronterasX[23] = 256  fronterasY[23] = 17
    fronterasX[24] = 270  fronterasY[24] = 16
    fronterasX[25] = 280  fronterasY[25] = 15
    fronterasX[26] = 295  fronterasY[26] = 14
    fronterasX[27] = 316  fronterasY[27] = 14
    fronterasX[28] = 324  fronterasY[28] = 16
    fronterasX[29] = 333  fronterasY[29] = 17
    fronterasX[30] = 337  fronterasY[30] = 17
    fronterasX[31] = 342  fronterasY[31] = 16
    fronterasX[32] = 344  fronterasY[32] = 18
    fronterasX[33] = 364  fronterasY[33] = 19
    fronterasX[34] = 375  fronterasY[34] = 19
    fronterasX[35] = 383  fronterasY[35] = 18
    fronterasX[36] = 395  fronterasY[36] = 18
    fronterasX[37] = 399  fronterasY[37] = 19
    fronterasX[38] = 407  fronterasY[38] = 18
    fronterasX[39] = 413  fronterasY[39] = 19
    fronterasX[40] = 417  fronterasY[40] = 20
    fronterasX[41] = 424  fronterasY[41] = 19
    fronterasX[42] = 433  fronterasY[42] = 20
    fronterasX[43] = 444  fronterasY[43] = 20
    fronterasX[44] = 451  fronterasY[44] = 19
    fronterasX[45] = 462  fronterasY[45] = 19
    fronterasX[46] = 471  fronterasY[46] = 20
    fronterasX[47] = 474  fronterasY[47] = 20
    fronterasX[48] = 476  fronterasY[48] = 19
    fronterasX[49] = 479  fronterasY[49] = 19
    fronterasX[50] = 481  fronterasY[50] = 20
    fronterasX[51] = 497  fronterasY[51] = 20
    fronterasX[52] = 499  fronterasY[52] = 22
    fronterasX[53] = 501  fronterasY[53] = 24
    fronterasX[54] = 505  fronterasY[54] = 23
    fronterasX[55] = 507  fronterasY[55] = 21
    fronterasX[56] = 510  fronterasY[56] = 19
    fronterasX[57] = 511  fronterasY[57] = 21
    fronterasX[58] = 515  fronterasY[58] = 21
    fronterasX[59] = 523  fronterasY[59] = 20
    fronterasX[60] = 531  fronterasY[60] = 21
    fronterasX[61] = 536  fronterasY[61] = 21
    fronterasX[62] = 542  fronterasY[62] = 21
    fronterasX[63] = 546  fronterasY[63] = 21
    fronterasX[64] = 553  fronterasY[64] = 21
    fronterasX[65] = 561  fronterasY[65] = 21
    fronterasX[66] = 569  fronterasY[66] = 21
    fronterasX[67] = 577  fronterasY[67] = 22
    fronterasX[68] = 573  fronterasY[68] = 23
    fronterasX[69] = 577  fronterasY[69] = 25
    fronterasX[70] = 580  fronterasY[70] = 26
    fronterasX[71] = 585  fronterasY[71] = 27
    fronterasX[72] = 593  fronterasY[72] = 28
    fronterasX[73] = 593  fronterasY[73] = 31
    fronterasX[74] = 592  fronterasY[74] = 32
    fronterasX[75] = 597  fronterasY[75] = 30
    fronterasX[76] = 605  fronterasY[76] = 30
    fronterasX[77] = 613  fronterasY[77] = 29
    fronterasX[78] = 622  fronterasY[78] = 30
    fronterasX[79] = 626  fronterasY[79] = 32
    fronterasX[80] = 625  fronterasY[80] = 35
    fronterasX[81] = 630  fronterasY[81] = 36
    fronterasX[82] = 635  fronterasY[82] = 36
    fronterasX[83] = 639  fronterasY[83] = 37
    fronterasX[84] = 644  fronterasY[84] = 35
    fronterasX[85] = 651  fronterasY[85] = 34
    fronterasX[86] = 659  fronterasY[86] = 35
    fronterasX[87] = 668  fronterasY[87] = 34
    fronterasX[88] = 678  fronterasY[88] = 35
    fronterasX[89] = 686  fronterasY[89] = 36
    fronterasX[90] = 696  fronterasY[90] = 36
    fronterasX[91] = 707  fronterasY[91] = 37
    fronterasX[92] = 717  fronterasY[92] = 37
    fronterasX[93] = 719  fronterasY[93] = 37

    SF_drawPoliLine(fronterasX, fronterasY, 93, color_fronteras)

    fronterasX[1] = 2  fronterasY[1] = 36
    fronterasX[2] = 19  fronterasY[2] = 38

    SF_drawPoliLine(fronterasX, fronterasY, 2, color_fronteras)

    -- Islandia

    fronterasX[1] = 220  fronterasY[1] = 28
    fronterasX[2] = 226  fronterasY[2] = 29
    fronterasX[3] = 234  fronterasY[3] = 29
    fronterasX[4] = 239  fronterasY[4] = 29
    fronterasX[5] = 244  fronterasY[5] = 31
    fronterasX[6] = 249  fronterasY[6] = 36
    fronterasX[7] = 251  fronterasY[7] = 37
    fronterasX[8] = 248  fronterasY[8] = 38
    fronterasX[9] = 250  fronterasY[9] = 40
    fronterasX[10] = 251  fronterasY[10] = 38
    fronterasX[11] = 253  fronterasY[11] = 38
    fronterasX[12] = 255  fronterasY[12] = 39
    fronterasX[13] = 255  fronterasY[13] = 40
    fronterasX[14] = 250  fronterasY[14] = 42
    fronterasX[15] = 253  fronterasY[15] = 44
    fronterasX[16] = 254  fronterasY[16] = 43
    fronterasX[17] = 258  fronterasY[17] = 43
    fronterasX[18] = 257  fronterasY[18] = 45
    fronterasX[19] = 258  fronterasY[19] = 47
    fronterasX[20] = 256  fronterasY[20] = 49
    fronterasX[21] = 254  fronterasY[21] = 50
    fronterasX[22] = 255  fronterasY[22] = 51
    fronterasX[23] = 257  fronterasY[23] = 51
    fronterasX[24] = 260  fronterasY[24] = 53
    fronterasX[25] = 259  fronterasY[25] = 56
    fronterasX[26] = 261  fronterasY[26] = 58
    fronterasX[27] = 264  fronterasY[27] = 60
    fronterasX[28] = 266  fronterasY[28] = 60
    fronterasX[29] = 269  fronterasY[29] = 60
    fronterasX[30] = 271  fronterasY[30] = 62
    fronterasX[31] = 273  fronterasY[31] = 62
    fronterasX[32] = 276  fronterasY[32] = 58
    fronterasX[33] = 275  fronterasY[33] = 56
    fronterasX[34] = 277  fronterasY[34] = 55
    fronterasX[35] = 279  fronterasY[35] = 54
    fronterasX[36] = 281  fronterasY[36] = 51
    fronterasX[37] = 284  fronterasY[37] = 50
    fronterasX[38] = 290  fronterasY[38] = 49
    fronterasX[39] = 295  fronterasY[39] = 46
    fronterasX[40] = 300  fronterasY[40] = 45
    fronterasX[41] = 307  fronterasY[41] = 44
    fronterasX[42] = 315  fronterasY[42] = 42
    fronterasX[43] = 311  fronterasY[43] = 41
    fronterasX[44] = 309  fronterasY[44] = 40
    fronterasX[45] = 305  fronterasY[45] = 39
    fronterasX[46] = 308  fronterasY[46] = 38
    fronterasX[47] = 311  fronterasY[47] = 39
    fronterasX[48] = 313  fronterasY[48] = 40
    fronterasX[49] = 316  fronterasY[49] = 40
    fronterasX[50] = 311  fronterasY[50] = 38
    fronterasX[51] = 307  fronterasY[51] = 36
    fronterasX[52] = 310  fronterasY[52] = 35
    fronterasX[53] = 314  fronterasY[53] = 34
    fronterasX[54] = 322  fronterasY[54] = 33
    fronterasX[55] = 318  fronterasY[55] = 32
    fronterasX[56] = 321  fronterasY[56] = 31
    fronterasX[57] = 321  fronterasY[57] = 30
    fronterasX[58] = 318  fronterasY[58] = 29
    fronterasX[59] = 322  fronterasY[59] = 26
    fronterasX[60] = 322  fronterasY[60] = 25
    fronterasX[61] = 327  fronterasY[61] = 24
    fronterasX[62] = 331  fronterasY[62] = 22
    fronterasX[63] = 334  fronterasY[63] = 21
    fronterasX[64] = 325  fronterasY[64] = 21
    fronterasX[65] = 321  fronterasY[65] = 21
    fronterasX[66] = 318  fronterasY[66] = 20
    fronterasX[67] = 312  fronterasY[67] = 19
    fronterasX[68] = 308  fronterasY[68] = 18
    fronterasX[69] = 304  fronterasY[69] = 17
    fronterasX[70] = 300  fronterasY[70] = 18
    fronterasX[71] = 299  fronterasY[71] = 17
    fronterasX[72] = 294  fronterasY[72] = 17
    fronterasX[73] = 293  fronterasY[73] = 18
    fronterasX[74] = 291  fronterasY[74] = 18
    fronterasX[75] = 289  fronterasY[75] = 17
    fronterasX[76] = 287  fronterasY[76] = 18
    fronterasX[77] = 285  fronterasY[77] = 18
    fronterasX[78] = 283  fronterasY[78] = 19
    fronterasX[79] = 280  fronterasY[79] = 18
    fronterasX[80] = 279  fronterasY[80] = 18
    fronterasX[81] = 275  fronterasY[81] = 18
    fronterasX[82] = 271  fronterasY[82] = 18
    fronterasX[83] = 269  fronterasY[83] = 19
    fronterasX[84] = 266  fronterasY[84] = 19
    fronterasX[85] = 264  fronterasY[85] = 20
    fronterasX[86] = 261  fronterasY[86] = 20
    fronterasX[87] = 258  fronterasY[87] = 19
    fronterasX[88] = 260  fronterasY[88] = 22
    fronterasX[89] = 254  fronterasY[89] = 20
    fronterasX[90] = 252  fronterasY[90] = 21
    fronterasX[91] = 250  fronterasY[91] = 20
    fronterasX[92] = 245  fronterasY[92] = 20
    fronterasX[93] = 239  fronterasY[93] = 21
    fronterasX[94] = 233  fronterasY[94] = 22
    fronterasX[95] = 229  fronterasY[95] = 23
    fronterasX[96] = 224  fronterasY[96] = 24
    fronterasX[97] = 229  fronterasY[97] = 25
    fronterasX[98] = 224  fronterasY[98] = 26
    fronterasX[99] = 221  fronterasY[99] = 27
    fronterasX[100] = 214 fronterasY[100] = 27
    fronterasX[101] = 220  fronterasY[101] = 28
    SF_drawPoliLine(fronterasX, fronterasY, 101, color_fronteras)

    --America
-- Africa, Arabia saudi e India
-- China y Japon
    fronterasX[1] = 606  fronterasY[1] = 107
    fronterasX[2] = 602  fronterasY[2] = 109
    fronterasX[3] = 601  fronterasY[3] = 107
    fronterasX[4] = 598  fronterasY[4] = 107
    fronterasX[5] = 602  fronterasY[5] = 105
    fronterasX[6] = 608  fronterasY[6] = 100
    fronterasX[7] = 606  fronterasY[7] = 104
    fronterasX[8] = 607  fronterasY[8] = 105
    fronterasX[9] = 612  fronterasY[9] = 104
    fronterasX[10] = 615  fronterasY[10] = 104
    fronterasX[11] = 613  fronterasY[11] = 107
    fronterasX[12] = 615  fronterasY[12] = 108
    fronterasX[13] = 617  fronterasY[13] = 108
    fronterasX[14] = 617  fronterasY[14] = 111
    fronterasX[15] = 616  fronterasY[15] = 113
    fronterasX[16] = 618  fronterasY[16] = 114
    fronterasX[17] = 619  fronterasY[17] = 114
    fronterasX[18] = 624  fronterasY[18] = 111
    fronterasX[19] = 622  fronterasY[19] = 107
    fronterasX[20] = 620  fronterasY[20] = 104
    fronterasX[21] = 623  fronterasY[21] = 101
    fronterasX[22] = 628  fronterasY[22] = 96
    fronterasX[23] = 633  fronterasY[23] = 97
    fronterasX[24] = 640  fronterasY[24] = 92
    fronterasX[25] = 646  fronterasY[25] = 85
    fronterasX[26] = 647  fronterasY[26] = 79
    fronterasX[27] = 649  fronterasY[27] = 80
    fronterasX[28] = 649  fronterasY[28] = 85
    fronterasX[29] = 649  fronterasY[29] = 91
    fronterasX[30] = 648  fronterasY[30] = 95
    fronterasX[31] = 645  fronterasY[31] = 98
    fronterasX[32] = 646  fronterasY[32] = 101
    fronterasX[33] = 645  fronterasY[33] = 102
    fronterasX[34] = 645  fronterasY[34] = 105
    fronterasX[35] = 642  fronterasY[35] = 108
    fronterasX[36] = 638  fronterasY[36] = 108
    fronterasX[37] = 638  fronterasY[37] = 110
    fronterasX[38] = 635  fronterasY[38] = 112
    fronterasX[39] = 631  fronterasY[39] = 112
    fronterasX[40] = 628  fronterasY[40] = 113
    fronterasX[41] = 624  fronterasY[41] = 116
    fronterasX[42] = 624  fronterasY[42] = 118
    fronterasX[43] = 626  fronterasY[43] = 122
    fronterasX[44] = 628  fronterasY[44] = 118
    fronterasX[45] = 629  fronterasY[45] = 116
    fronterasX[46] = 630  fronterasY[46] = 118
    fronterasX[47] = 631  fronterasY[47] = 116
    fronterasX[48] = 633  fronterasY[48] = 116
    fronterasX[49] = 634  fronterasY[49] = 115
    fronterasX[50] = 636  fronterasY[50] = 116
    fronterasX[51] = 639  fronterasY[51] = 114
    fronterasX[52] = 641  fronterasY[52] = 114
    fronterasX[53] = 644  fronterasY[53] = 112
    fronterasX[54] = 647  fronterasY[54] = 111
    fronterasX[55] = 647  fronterasY[55] = 108
    fronterasX[56] = 649  fronterasY[56] = 105
    fronterasX[57] = 649  fronterasY[57] = 103
    fronterasX[58] = 647  fronterasY[58] = 101
    fronterasX[59] = 647  fronterasY[59] = 99
    fronterasX[60] = 646  fronterasY[60] = 98
    fronterasX[61] = 649  fronterasY[61] = 98
    fronterasX[62] = 652  fronterasY[62] = 100
    fronterasX[63] = 653  fronterasY[63] = 97
    fronterasX[64] = 657  fronterasY[64] = 96
    fronterasX[65] = 652  fronterasY[65] = 94
    fronterasX[66] = 649  fronterasY[66] = 91
    fronterasX[67] = 652  fronterasY[67] = 89
    fronterasX[68] = 651  fronterasY[68] = 87
    fronterasX[69] = 652  fronterasY[69] = 84
    fronterasX[70] = 654  fronterasY[70] = 84
    fronterasX[71] = 653  fronterasY[71] = 81
    fronterasX[72] = 652  fronterasY[72] = 79
    fronterasX[73] = 653  fronterasY[73] = 76
    fronterasX[74] = 651  fronterasY[74] = 75
    fronterasX[75] = 648  fronterasY[75] = 76
    fronterasX[76] = 645  fronterasY[76] = 74
    fronterasX[77] = 642  fronterasY[77] = 75
    fronterasX[78] = 640  fronterasY[78] = 72
    fronterasX[79] = 641  fronterasY[79] = 69
    fronterasX[80] = 646  fronterasY[80] = 66
    fronterasX[81] = 653  fronterasY[81] = 64
    fronterasX[82] = 662  fronterasY[82] = 63
    fronterasX[83] = 670  fronterasY[83] = 63
    fronterasX[84] = 676  fronterasY[84] = 62
    fronterasX[85] = 682  fronterasY[85] = 59
    fronterasX[86] = 686  fronterasY[86] = 59
    fronterasX[87] = 688  fronterasY[87] = 61
    fronterasX[88] = 686  fronterasY[88] = 64
    fronterasX[89] = 681  fronterasY[89] = 67
    fronterasX[90] = 678  fronterasY[90] = 70
    fronterasX[91] = 677  fronterasY[91] = 72
    fronterasX[92] = 678  fronterasY[92] = 75
    fronterasX[93] = 680  fronterasY[93] = 79
    fronterasX[94] = 683  fronterasY[94] = 79
    fronterasX[95] = 683  fronterasY[95] = 77
    fronterasX[96] = 686  fronterasY[96] = 77
    fronterasX[97] = 687  fronterasY[97] = 74
    fronterasX[98] = 690  fronterasY[98] = 74
    fronterasX[99] = 692  fronterasY[99] = 72
    fronterasX[100] = 693  fronterasY[100] = 70
    fronterasX[101] = 693  fronterasY[101] = 68
    fronterasX[102] = 692  fronterasY[102] = 66
    fronterasX[103] = 694  fronterasY[103] = 65
    fronterasX[104] = 695  fronterasY[104] = 63
    fronterasX[105] = 698  fronterasY[105] = 63
    fronterasX[106] = 701  fronterasY[106] = 61
    fronterasX[107] = 705  fronterasY[107] = 62
    fronterasX[108] = 712  fronterasY[108] = 61
    fronterasX[109] = 717  fronterasY[109] = 59
    fronterasX[110] = 719  fronterasY[110] = 59
    SF_drawPoliLine(fronterasX, fronterasY, 110, color_fronteras)
    fronterasX[1] = 609  fronterasY[1] = 109
    fronterasX[2] = 606  fronterasY[2] = 107
    SF_drawPoliLine(fronterasX, fronterasY, 2, color_fronteras)

    -- Europa
-- Mediterraneo
    fronterasX[1] = 432  fronterasY[1] = 92
    fronterasX[2] = 429  fronterasY[2] = 91
    fronterasX[3] = 433  fronterasY[3] = 89
    fronterasX[4] = 437  fronterasY[4] = 88
    fronterasX[5] = 436  fronterasY[5] = 90
    fronterasX[6] = 437  fronterasY[6] = 92
    fronterasX[7] = 434  fronterasY[7] = 92
    fronterasX[8] = 437  fronterasY[8] = 94
    fronterasX[9] = 441  fronterasY[9] = 97
    fronterasX[10] = 443  fronterasY[10] = 99
    fronterasX[11] = 440  fronterasY[11] = 101
    fronterasX[12] = 433  fronterasY[12] = 101
    fronterasX[13] = 429  fronterasY[13] = 99
    fronterasX[14] = 425  fronterasY[14] = 100
    fronterasX[15] = 420  fronterasY[15] = 100
    fronterasX[16] = 418  fronterasY[16] = 102
    fronterasX[17] = 413  fronterasY[17] = 103
    fronterasX[18] = 412  fronterasY[18] = 104
    fronterasX[19] = 412  fronterasY[19] = 106
    fronterasX[20] = 411  fronterasY[20] = 108
    fronterasX[21] = 413  fronterasY[21] = 109
    fronterasX[22] = 414  fronterasY[22] = 110
    fronterasX[23] = 417  fronterasY[23] = 110
    fronterasX[24] = 419  fronterasY[24] = 110
    fronterasX[25] = 422  fronterasY[25] = 110
    fronterasX[26] = 424  fronterasY[26] = 109
    fronterasX[27] = 426  fronterasY[27] = 110
    fronterasX[28] = 428  fronterasY[28] = 109
    fronterasX[29] = 432  fronterasY[29] = 111
    fronterasX[30] = 431  fronterasY[30] = 113
    fronterasX[31] = 430  fronterasY[31] = 116
    fronterasX[32] = 429  fronterasY[32] = 118
    fronterasX[33] = 428  fronterasY[33] = 120
    fronterasX[34] = 424  fronterasY[34] = 121
    fronterasX[35] = 422  fronterasY[35] = 123
    fronterasX[36] = 421  fronterasY[36] = 121
    fronterasX[37] = 419  fronterasY[37] = 121
    fronterasX[38] = 415  fronterasY[38] = 120
    fronterasX[39] = 410  fronterasY[39] = 119
    fronterasX[40] = 404  fronterasY[40] = 117
    fronterasX[41] = 402  fronterasY[41] = 117
    fronterasX[42] = 400  fronterasY[42] = 118
    fronterasX[43] = 399  fronterasY[43] = 120
    fronterasX[44] = 399  fronterasY[44] = 122
    fronterasX[45] = 397  fronterasY[45] = 122
    fronterasX[46] = 390  fronterasY[46] = 120
    fronterasX[47] = 388  fronterasY[47] = 118
    fronterasX[48] = 385  fronterasY[48] = 117
    fronterasX[49] = 380  fronterasY[49] = 116
    fronterasX[50] = 379  fronterasY[50] = 115
    fronterasX[51] = 381  fronterasY[51] = 113
    fronterasX[52] = 380  fronterasY[52] = 111
    fronterasX[53] = 380  fronterasY[53] = 109
    fronterasX[54] = 378  fronterasY[54] = 108
    fronterasX[55] = 376  fronterasY[55] = 109
    fronterasX[56] = 373  fronterasY[56] = 109
    fronterasX[57] = 371  fronterasY[57] = 109
    fronterasX[58] = 367  fronterasY[58] = 109
    fronterasX[59] = 365  fronterasY[59] = 109
    fronterasX[60] = 362  fronterasY[60] = 111
    fronterasX[61] = 359  fronterasY[61] = 112
    fronterasX[62] = 356  fronterasY[62] = 112
    fronterasX[63] = 353  fronterasY[63] = 113
    fronterasX[64] = 352  fronterasY[64] = 112
    fronterasX[65] = 350  fronterasY[65] = 111
    SF_drawPoliLine(fronterasX, fronterasY, 65, color_fronteras)
    fronterasX[1] = 428  fronterasY[1] = 94
    fronterasX[2] = 432  fronterasY[2] = 92
    SF_drawPoliLine(fronterasX, fronterasY, 2, color_fronteras)

    -- Australia
    fronterasX[1] = 649  fronterasY[1] = 208
    fronterasX[2] = 648  fronterasY[2] = 212
    fronterasX[3] = 648  fronterasY[3] = 217
    fronterasX[4] = 645  fronterasY[4] = 220
    fronterasX[5] = 642  fronterasY[5] = 218
    fronterasX[6] = 639  fronterasY[6] = 216
    fronterasX[7] = 636  fronterasY[7] = 214
    fronterasX[8] = 637  fronterasY[8] = 213
    fronterasX[9] = 639  fronterasY[9] = 213
    fronterasX[10] = 639  fronterasY[10] = 212
    fronterasX[11] = 637  fronterasY[11] = 211
    fronterasX[12] = 638  fronterasY[12] = 209
    fronterasX[13] = 638  fronterasY[13] = 207
    fronterasX[14] = 633  fronterasY[14] = 208
    fronterasX[15] = 630  fronterasY[15] = 207
    fronterasX[16] = 628  fronterasY[16] = 207
    fronterasX[17] = 629  fronterasY[17] = 209
    fronterasX[18] = 625  fronterasY[18] = 207
    fronterasX[19] = 625  fronterasY[19] = 210
    fronterasX[20] = 623  fronterasY[20] = 213
    fronterasX[21] = 620  fronterasY[21] = 213
    fronterasX[22] = 618  fronterasY[22] = 212
    fronterasX[23] = 615  fronterasY[23] = 213
    fronterasX[24] = 612  fronterasY[24] = 216
    fronterasX[25] = 611  fronterasY[25] = 218
    fronterasX[26] = 609  fronterasY[26] = 217
    fronterasX[27] = 607  fronterasY[27] = 219
    fronterasX[28] = 608  fronterasY[28] = 221
    fronterasX[29] = 605  fronterasY[29] = 224
    fronterasX[30] = 600  fronterasY[30] = 225
    fronterasX[31] = 594  fronterasY[31] = 227
    fronterasX[32] = 591  fronterasY[32] = 228
    fronterasX[33] = 590  fronterasY[33] = 233
    fronterasX[34] = 590  fronterasY[34] = 237
    fronterasX[35] = 593  fronterasY[35] = 243
    fronterasX[36] = 594  fronterasY[36] = 247
    fronterasX[37] = 595  fronterasY[37] = 251
    fronterasX[38] = 593  fronterasY[38] = 254
    fronterasX[39] = 597  fronterasY[39] = 255
    fronterasX[40] = 601  fronterasY[40] = 253
    fronterasX[41] = 607  fronterasY[41] = 252
    fronterasX[42] = 612  fronterasY[42] = 251
    fronterasX[43] = 618  fronterasY[43] = 249
    fronterasX[44] = 623  fronterasY[44] = 248
    fronterasX[45] = 629  fronterasY[45] = 248
    fronterasX[46] = 632  fronterasY[46] = 250
    fronterasX[47] = 634  fronterasY[47] = 252
    fronterasX[48] = 636  fronterasY[48] = 254
    fronterasX[49] = 638  fronterasY[49] = 252
    fronterasX[50] = 640  fronterasY[50] = 251
    fronterasX[51] = 639  fronterasY[51] = 254
    fronterasX[52] = 638  fronterasY[52] = 257
    fronterasX[53] = 641  fronterasY[53] = 258
    fronterasX[54] = 642  fronterasY[54] = 257
    fronterasX[55] = 643  fronterasY[55] = 258
    fronterasX[56] = 645  fronterasY[56] = 261
    fronterasX[57] = 647  fronterasY[57] = 262
    fronterasX[58] = 650  fronterasY[58] = 262
    fronterasX[59] = 652  fronterasY[59] = 262
    fronterasX[60] = 654  fronterasY[60] = 261
    fronterasX[61] = 656  fronterasY[61] = 262
    fronterasX[62] = 660  fronterasY[62] = 261
    fronterasX[63] = 662  fronterasY[63] = 261
    fronterasX[64] = 664  fronterasY[64] = 260
    fronterasX[65] = 665  fronterasY[65] = 258
    fronterasX[66] = 666  fronterasY[66] = 255
    fronterasX[67] = 668  fronterasY[67] = 251
    fronterasX[68] = 671  fronterasY[68] = 247
    fronterasX[69] = 672  fronterasY[69] = 241
    fronterasX[70] = 671  fronterasY[70] = 236
    fronterasX[71] = 667  fronterasY[71] = 232
    fronterasX[72] = 665  fronterasY[72] = 229
    fronterasX[73] = 662  fronterasY[73] = 226
    fronterasX[74] = 658  fronterasY[74] = 223
    fronterasX[75] = 657  fronterasY[75] = 219
    fronterasX[76] = 656  fronterasY[76] = 215
    fronterasX[77] = 655  fronterasY[77] = 213
    fronterasX[78] = 652  fronterasY[78] = 212
    fronterasX[79] = 652  fronterasY[79] = 209
    fronterasX[80] = 651  fronterasY[80] = 208
    fronterasX[81] = 650  fronterasY[81] = 206
    fronterasX[82] = 649  fronterasY[82] = 208
    SF_drawPoliLine(fronterasX, fronterasY, 82, color_fronteras)

    -- Antartida

    fronterasX[1] = 13  fronterasY[1] = 341
    fronterasX[2] = 23  fronterasY[2] = 341
    fronterasX[3] = 36  fronterasY[3] = 340
    fronterasX[4] = 38  fronterasY[4] = 338
    fronterasX[5] = 46  fronterasY[5] = 340
    fronterasX[6] = 53  fronterasY[6] = 338
    fronterasX[7] = 62  fronterasY[7] = 336
    fronterasX[8] = 77  fronterasY[8] = 335
    fronterasX[9] = 93  fronterasY[9] = 334
    fronterasX[10] = 97  fronterasY[10] = 333
    fronterasX[11] = 101  fronterasY[11] = 331
    fronterasX[12] = 108  fronterasY[12] = 333
    fronterasX[13] = 112  fronterasY[13] = 331
    fronterasX[14] = 118  fronterasY[14] = 333
    fronterasX[15] = 128  fronterasY[15] = 333
    fronterasX[16] = 135  fronterasY[16] = 333
    fronterasX[17] = 137  fronterasY[17] = 331
    fronterasX[18] = 142  fronterasY[18] = 333
    fronterasX[19] = 149  fronterasY[19] = 333
    fronterasX[20] = 150  fronterasY[20] = 331
    fronterasX[21] = 163  fronterasY[21] = 329
    fronterasX[22] = 165  fronterasY[22] = 332
    fronterasX[23] = 178  fronterasY[23] = 331
    fronterasX[24] = 187  fronterasY[24] = 332
    fronterasX[25] = 195  fronterasY[25] = 332
    fronterasX[26] = 200  fronterasY[26] = 330
    fronterasX[27] = 202  fronterasY[27] = 330
    fronterasX[28] = 203  fronterasY[28] = 332
    fronterasX[29] = 207  fronterasY[29] = 332
    fronterasX[30] = 204  fronterasY[30] = 330
    fronterasX[31] = 211  fronterasY[31] = 330
    fronterasX[32] = 212  fronterasY[32] = 330
    fronterasX[33] = 207  fronterasY[33] = 328
    fronterasX[34] = 205  fronterasY[34] = 326
    fronterasX[35] = 208  fronterasY[35] = 323
    fronterasX[36] = 213  fronterasY[36] = 327
    fronterasX[37] = 215  fronterasY[37] = 327
    fronterasX[38] = 213  fronterasY[38] = 325
    fronterasX[39] = 213  fronterasY[39] = 322
    fronterasX[40] = 219  fronterasY[40] = 323
    fronterasX[41] = 222  fronterasY[41] = 328
    fronterasX[42] = 220  fronterasY[42] = 330
    fronterasX[43] = 214  fronterasY[43] = 331
    fronterasX[44] = 221  fronterasY[44] = 331
    fronterasX[45] = 224  fronterasY[45] = 330
    fronterasX[46] = 224  fronterasY[46] = 327
    fronterasX[47] = 222  fronterasY[47] = 324
    fronterasX[48] = 224  fronterasY[48] = 323
    fronterasX[49] = 223  fronterasY[49] = 321
    fronterasX[50] = 224  fronterasY[50] = 320
    fronterasX[51] = 222  fronterasY[51] = 319
    fronterasX[52] = 229  fronterasY[52] = 315
    fronterasX[53] = 234  fronterasY[53] = 313
    fronterasX[54] = 240  fronterasY[54] = 311
    fronterasX[55] = 247  fronterasY[55] = 312
    fronterasX[56] = 242  fronterasY[56] = 314
    fronterasX[57] = 237  fronterasY[57] = 316
    fronterasX[58] = 235  fronterasY[58] = 318
    fronterasX[59] = 232  fronterasY[59] = 318
    fronterasX[60] = 229  fronterasY[60] = 319
    fronterasX[61] = 229  fronterasY[61] = 321
    fronterasX[62] = 231  fronterasY[62] = 323
    fronterasX[63] = 235  fronterasY[63] = 325
    fronterasX[64] = 238  fronterasY[64] = 327
    fronterasX[65] = 239  fronterasY[65] = 329
    fronterasX[66] = 237  fronterasY[66] = 333
    fronterasX[67] = 235  fronterasY[67] = 335
    fronterasX[68] = 264  fronterasY[68] = 340
    fronterasX[69] = 288  fronterasY[69] = 341
    fronterasX[70] = 303  fronterasY[70] = 338
    fronterasX[71] = 312  fronterasY[71] = 335
    fronterasX[72] = 313  fronterasY[72] = 334
    fronterasX[73] = 316  fronterasY[73] = 334
    fronterasX[74] = 325  fronterasY[74] = 331
    fronterasX[75] = 331  fronterasY[75] = 330
    fronterasX[76] = 335  fronterasY[76] = 329
    fronterasX[77] = 337  fronterasY[77] = 328
    fronterasX[78] = 341  fronterasY[78] = 327
    fronterasX[79] = 345  fronterasY[79] = 329
    fronterasX[80] = 348  fronterasY[80] = 326
    fronterasX[81] = 349  fronterasY[81] = 326
    fronterasX[82] = 351  fronterasY[82] = 328
    fronterasX[83] = 355  fronterasY[83] = 328
    fronterasX[84] = 355  fronterasY[84] = 326
    fronterasX[85] = 356  fronterasY[85] = 326
    fronterasX[86] = 359  fronterasY[86] = 329
    fronterasX[87] = 362  fronterasY[87] = 327
    fronterasX[88] = 364  fronterasY[88] = 326
    fronterasX[89] = 370  fronterasY[89] = 326
    fronterasX[90] = 385  fronterasY[90] = 325
    fronterasX[91] = 403  fronterasY[91] = 326
    fronterasX[92] = 421  fronterasY[92] = 323
    fronterasX[93] = 427  fronterasY[93] = 321
    fronterasX[94] = 432  fronterasY[94] = 324
    fronterasX[95] = 438  fronterasY[95] = 325
    fronterasX[96] = 440  fronterasY[96] = 322
    fronterasX[97] = 451  fronterasY[97] = 321
    fronterasX[98] = 461  fronterasY[98] = 319
    fronterasX[99] = 465  fronterasY[99] = 317
    fronterasX[100] = 471  fronterasY[100] = 317
    fronterasX[101] = 478  fronterasY[101] = 320
    fronterasX[102] = 494  fronterasY[102] = 321
    fronterasX[103] = 499  fronterasY[103] = 321
    fronterasX[104] = 500  fronterasY[104] = 327
    fronterasX[105] = 499  fronterasY[105] = 329
    fronterasX[106] = 503  fronterasY[106] = 329
    fronterasX[107] = 508  fronterasY[107] = 325
    fronterasX[108] = 516  fronterasY[108] = 322
    fronterasX[109] = 531  fronterasY[109] = 319
    fronterasX[110] = 543  fronterasY[110] = 319
    fronterasX[111] = 553  fronterasY[111] = 317
    fronterasX[112] = 567  fronterasY[112] = 316
    fronterasX[113] = 575  fronterasY[113] = 317
    fronterasX[114] = 582  fronterasY[114] = 319
    fronterasX[115] = 588  fronterasY[115] = 316
    fronterasX[116] = 593  fronterasY[116] = 316
    fronterasX[117] = 597  fronterasY[117] = 318
    fronterasX[118] = 603  fronterasY[118] = 319
    fronterasX[119] = 616  fronterasY[119] = 318
    fronterasX[120] = 623  fronterasY[120] = 319
    fronterasX[121] = 633  fronterasY[121] = 317
    fronterasX[122] = 634  fronterasY[122] = 314
    fronterasX[123] = 637  fronterasY[123] = 317
    fronterasX[124] = 648  fronterasY[124] = 319
    fronterasX[125] = 664  fronterasY[125] = 323
    fronterasX[126] = 679  fronterasY[126] = 325
    fronterasX[127] = 701  fronterasY[127] = 328
    fronterasX[128] = 704  fronterasY[128] = 329
    fronterasX[129] = 707  fronterasY[129] = 329
    fronterasX[130] = 708  fronterasY[130] = 330
    fronterasX[131] = 705  fronterasY[131] = 332
    fronterasX[132] = 700  fronterasY[132] = 334
    fronterasX[133] = 695  fronterasY[133] = 335
    fronterasX[134] = 692  fronterasY[134] = 338
    fronterasX[135] = 694  fronterasY[135] = 341
    fronterasX[136] = 699  fronterasY[136] = 342
    fronterasX[137] = 700  fronterasY[137] = 340
    fronterasX[138] = 706  fronterasY[138] = 342
    fronterasX[139] = 713  fronterasY[139] = 342
    fronterasX[140] = 719  fronterasY[140] = 342
    SF_drawPoliLine(fronterasX, fronterasY, 140, color_fronteras)
    fronterasX[1] = 2  fronterasY[1] = 341
    fronterasX[2] = 13  fronterasY[2] = 341
    SF_drawPoliLine(fronterasX, fronterasY, 2, color_fronteras)

    -- Inglaterra

    fronterasX[1] = 363  fronterasY[1] = 81
    fronterasX[2] = 364  fronterasY[2] = 79
    fronterasX[3] = 364  fronterasY[3] = 77
    fronterasX[4] = 362  fronterasY[4] = 77
    fronterasX[5] = 361  fronterasY[5] = 75
    fronterasX[6] = 359  fronterasY[6] = 74
    fronterasX[7] = 358  fronterasY[7] = 72
    fronterasX[8] = 355  fronterasY[8] = 70
    fronterasX[9] = 357  fronterasY[9] = 68
    fronterasX[10] = 356  fronterasY[10] = 67
    fronterasX[11] = 353  fronterasY[11] = 68
    fronterasX[12] = 354  fronterasY[12] = 66
    fronterasX[13] = 355  fronterasY[13] = 65
    fronterasX[14] = 352  fronterasY[14] = 65
    fronterasX[15] = 350  fronterasY[15] = 67
    fronterasX[16] = 349  fronterasY[16] = 68
    fronterasX[17] = 349  fronterasY[17] = 70
    fronterasX[18] = 352  fronterasY[18] = 72
    fronterasX[19] = 354  fronterasY[19] = 73
    fronterasX[20] = 355  fronterasY[20] = 75
    fronterasX[21] = 353  fronterasY[21] = 77
    fronterasX[22] = 351  fronterasY[22] = 80
    fronterasX[23] = 355  fronterasY[23] = 79
    fronterasX[24] = 351  fronterasY[24] = 82
    fronterasX[25] = 358  fronterasY[25] = 81
    fronterasX[26] = 363  fronterasY[26] = 81
    SF_drawPoliLine(fronterasX, fronterasY, 26, color_fronteras)

    fronterasX[1] = 348  fronterasY[1] = 77
    fronterasX[2] = 349  fronterasY[2] = 73
    fronterasX[3] = 347  fronterasY[3] = 72
    fronterasX[4] = 346  fronterasY[4] = 73
    fronterasX[5] = 344  fronterasY[5] = 74
    fronterasX[6] = 342  fronterasY[6] = 74
    fronterasX[7] = 340  fronterasY[7] = 75
    fronterasX[8] = 342  fronterasY[8] = 77
    fronterasX[9] = 341  fronterasY[9] = 78
    fronterasX[10] = 342  fronterasY[10] = 79
    fronterasX[11] = 348  fronterasY[11] = 77
    SF_drawPoliLine(fronterasX, fronterasY, 11, color_fronteras)

    -- Madagascar
    fronterasX[1] = 455  fronterasY[1] = 213
    fronterasX[2] = 450  fronterasY[2] = 216
    fronterasX[3] = 448  fronterasY[3] = 220
    fronterasX[4] = 447  fronterasY[4] = 226
    fronterasX[5] = 447  fronterasY[5] = 232
    fronterasX[6] = 449  fronterasY[6] = 235
    fronterasX[7] = 454  fronterasY[7] = 234
    fronterasX[8] = 457  fronterasY[8] = 226
    fronterasX[9] = 460  fronterasY[9] = 217
    fronterasX[10] = 460  fronterasY[10] = 211
    fronterasX[11] = 459  fronterasY[11] = 209
    fronterasX[12] = 455  fronterasY[12] = 213
    SF_drawPoliLine(fronterasX, fronterasY, 12, color_fronteras)

    --Islandia
    fronterasX[1] = 316  fronterasY[1] = 53
    fronterasX[2] = 321  fronterasY[2] = 55
    fronterasX[3] = 327  fronterasY[3] = 53
    fronterasX[4] = 331  fronterasY[4] = 53
    fronterasX[5] = 333  fronterasY[5] = 51
    fronterasX[6] = 328  fronterasY[6] = 49
    fronterasX[7] = 323  fronterasY[7] = 50
    fronterasX[8] = 319  fronterasY[8] = 51
    fronterasX[9] = 316  fronterasY[9] = 49
    fronterasX[10] = 313  fronterasY[10] = 51
    fronterasX[11] = 316  fronterasY[11] = 53
    SF_drawPoliLine(fronterasX, fronterasY, 11, color_fronteras)


    --Indonesia
-- Nueva Zelanda
    fronterasX[1] = 703  fronterasY[1] = 274
    fronterasX[2] = 708  fronterasY[2] = 270
    fronterasX[3] = 713  fronterasY[3] = 267
    fronterasX[4] = 715  fronterasY[4] = 266
    fronterasX[5] = 714  fronterasY[5] = 270
    fronterasX[6] = 712  fronterasY[6] = 271
    fronterasX[7] = 710  fronterasY[7] = 274
    fronterasX[8] = 708  fronterasY[8] = 274
    fronterasX[9] = 708  fronterasY[9] = 277
    fronterasX[10] = 706  fronterasY[10] = 278
    fronterasX[11] = 704  fronterasY[11] = 279
    fronterasX[12] = 702  fronterasY[12] = 279
    fronterasX[13] = 700  fronterasY[13] = 278
    fronterasX[14] = 698  fronterasY[14] = 277
    fronterasX[15] = 703  fronterasY[15] = 274
    SF_drawPoliLine(fronterasX, fronterasY, 15, color_fronteras)

    fronterasX[1] = 717  fronterasY[1] = 266
    fronterasX[2] = 717  fronterasY[2] = 265
    fronterasX[3] = 715  fronterasY[3] = 264
    fronterasX[4] = 713  fronterasY[4] = 264
    fronterasX[5] = 715  fronterasY[5] = 262
    fronterasX[6] = 716  fronterasY[6] = 261
    fronterasX[7] = 716  fronterasY[7] = 258
    fronterasX[8] = 713  fronterasY[8] = 256
    fronterasX[9] = 712  fronterasY[9] = 255
    fronterasX[10] = 715  fronterasY[10] = 255
    fronterasX[11] = 717  fronterasY[11] = 256
    fronterasX[12] = 718  fronterasY[12] = 259
    fronterasX[13] = 719  fronterasY[13] = 261
    fronterasX[14] = 719  fronterasY[14] = 261
    fronterasX[15] = 719  fronterasY[15] = 266
    fronterasX[16] = 717  fronterasY[16] = 269
    fronterasX[17] = 717  fronterasY[17] = 266
    SF_drawPoliLine(fronterasX, fronterasY, 17, color_fronteras)

    fronterasX[1] = 5  fronterasY[1] = 53
    fronterasX[2] = 8  fronterasY[2] = 51
    fronterasX[3] = 11  fronterasY[3] = 50
    fronterasX[4] = 12  fronterasY[4] = 49
    fronterasX[5] = 10  fronterasY[5] = 48
    fronterasX[6] = 7  fronterasY[6] = 48
    fronterasX[7] = 5  fronterasY[7] = 47
    fronterasX[8] = 3  fronterasY[8] = 47
    fronterasX[9] = 2  fronterasY[9] = 45
    SF_drawPoliLine(fronterasX, fronterasY, 9, color_fronteras)
    fronterasX[1] = 2  fronterasY[1] = 54
    fronterasX[2] = 5  fronterasY[2] = 53
    SF_drawPoliLine(fronterasX, fronterasY, 2, color_fronteras)

    fronterasX[1] = 245  fronterasY[1] = 81
    fronterasX[2] = 242  fronterasY[2] = 84
    fronterasX[3] = 241  fronterasY[3] = 86
    fronterasX[4] = 245  fronterasY[4] = 87
    fronterasX[5] = 248  fronterasY[5] = 86
    fronterasX[6] = 249  fronterasY[6] = 88
    fronterasX[7] = 251  fronterasY[7] = 87
    fronterasX[8] = 252  fronterasY[8] = 90
    fronterasX[9] = 254  fronterasY[9] = 89
    fronterasX[10] = 253  fronterasY[10] = 87
    fronterasX[11] = 251  fronterasY[11] = 84
    fronterasX[12] = 249  fronterasY[12] = 84
    fronterasX[13] = 246  fronterasY[13] = 82
    fronterasX[14] = 248  fronterasY[14] = 80
    fronterasX[15] = 246  fronterasY[15] = 80
    fronterasX[16] = 245  fronterasY[16] = 81
    SF_drawPoliLine(fronterasX, fronterasY, 16, color_fronteras)

    fronterasX[1] = 190  fronterasY[1] = 139
    fronterasX[2] = 192  fronterasY[2] = 138
    fronterasX[3] = 194  fronterasY[3] = 137
    fronterasX[4] = 197  fronterasY[4] = 139
    fronterasX[5] = 199  fronterasY[5] = 139
    fronterasX[6] = 201  fronterasY[6] = 141
    fronterasX[7] = 203  fronterasY[7] = 142
    fronterasX[8] = 205  fronterasY[8] = 143
    fronterasX[9] = 209  fronterasY[9] = 143
    fronterasX[10] = 206  fronterasY[10] = 141
    fronterasX[11] = 204  fronterasY[11] = 140
    fronterasX[12] = 201  fronterasY[12] = 140
    fronterasX[13] = 199  fronterasY[13] = 138
    fronterasX[14] = 196  fronterasY[14] = 137
    fronterasX[15] = 193  fronterasY[15] = 137
    fronterasX[16] = 192  fronterasY[16] = 138
    fronterasX[17] = 190  fronterasY[17] = 137
    fronterasX[18] = 189  fronterasY[18] = 138
    fronterasX[19] = 190  fronterasY[19] = 139
    SF_drawPoliLine(fronterasX, fronterasY, 19, color_fronteras)

    fronterasX[1] = 212  fronterasY[1] = 145
    fronterasX[2] = 214  fronterasY[2] = 143
    fronterasX[3] = 216  fronterasY[3] = 143
    fronterasX[4] = 218  fronterasY[4] = 145
    fronterasX[5] = 220  fronterasY[5] = 145
    fronterasX[6] = 222  fronterasY[6] = 146
    fronterasX[7] = 224  fronterasY[7] = 146
    fronterasX[8] = 227  fronterasY[8] = 147
    fronterasX[9] = 223  fronterasY[9] = 146
    fronterasX[10] = 218  fronterasY[10] = 146
    fronterasX[11] = 215  fronterasY[11] = 147
    fronterasX[12] = 212  fronterasY[12] = 147
    fronterasX[13] = 210  fronterasY[13] = 145
    fronterasX[14] = 212  fronterasY[14] = 145
    SF_drawPoliLine(fronterasX, fronterasY, 14, color_fronteras)

    local px, py = SF_LatLonToXY(sgp_location.lat, sgp_location.lon)
    draw.line(px-3,py, px+3, py, sf_palette[1])
    draw.line(px, py-3, px, py+3, sf_palette[1])
end

function SF_drawSatMap( num_sat )
    if string.sub(sgp_sats[num_sat].nombre,1,7) == "IRIDIUM" then
        if sf_vision_nocturna then
            if sgp_sats[num_sat].visible then
                SF_drawSuperCrossMap(sgp_sats[num_sat].latitud,sgp_sats[num_sat].longitud, sf_color_white )
            elseif sgp_sats[num_sat].eclipsado then
                SF_drawSuperCrossMap(sgp_sats[num_sat].latitud,sgp_sats[num_sat].longitud, sf_palette[12] )
            else
                SF_drawSuperCrossMap(sgp_sats[num_sat].latitud,sgp_sats[num_sat].longitud, sf_palette[4] )
            end
        else
            if sgp_sats[num_sat].visible then
                SF_drawSuperCrossMap(sgp_sats[num_sat].latitud,sgp_sats[num_sat].longitud, sf_color_white )
            elseif sgp_sats[num_sat].eclipsado then
                SF_drawSuperCrossMap(sgp_sats[num_sat].latitud,sgp_sats[num_sat].longitud, sf_palette[12] )
            else
                SF_drawSuperCrossMap(sgp_sats[num_sat].latitud,sgp_sats[num_sat].longitud, sf_palette[4] )
            end
        end
    else
        if sf_vision_nocturna then
            if sgp_sats[num_sat].visible then
                SF_drawSuperPointMap(sgp_sats[num_sat].latitud,sgp_sats[num_sat].longitud, sf_color_white )
            elseif sgp_sats[num_sat].eclipsado then
                SF_drawSuperPointMap(sgp_sats[num_sat].latitud,sgp_sats[num_sat].longitud, sf_palette[12] )
            else
                SF_drawSuperPointMap(sgp_sats[num_sat].latitud,sgp_sats[num_sat].longitud, sf_palette[1] )
            end
        else
            if sgp_sats[num_sat].visible then
                SF_drawSuperPointMap(sgp_sats[num_sat].latitud,sgp_sats[num_sat].longitud, sf_color_white )
            elseif sgp_sats[num_sat].eclipsado then
                SF_drawSuperPointMap(sgp_sats[num_sat].latitud,sgp_sats[num_sat].longitud, sf_palette[12] )
            else
                SF_drawSuperPointMap(sgp_sats[num_sat].latitud,sgp_sats[num_sat].longitud, sf_palette[1] )
            end
        end
    end
    if num_sat == sf_selected_sat then
        SF_drawSatPath (num_sat, 30)
        SF_drawTextMap(sgp_sats[num_sat].latitud,sgp_sats[num_sat].longitud, sgp_sats[num_sat].nombre, sf_palette[1] )
    end
end

function SF_drawSatPath (num_sat, minutos)
    if sgp_sat_number <= 0 then
        return
    end

    SGP_getCurrentTime()
    local jtime = sgp_time.ujtime
    local i
    local lat_ant, lon_ant
    SGP_calculateSun (jtime)
    SGP_calculateSatellite (num_sat , jtime)
    lat_ant = sgp_sats[num_sat].latitud
    lon_ant = sgp_sats[num_sat].longitud
    for i = 1,minutos do
        SGP_calculateSun (jtime + const_julian_minute * i)
        SGP_calculateSatellite (num_sat , jtime + const_julian_minute * i)
        if math.abs (lon_ant-sgp_sats[num_sat].longitud) < 20 then
            if sf_vision_nocturna then
                if sgp_sats[num_sat].visible then
                    SF_drawLineMap(lat_ant, lon_ant, sgp_sats[num_sat].latitud,sgp_sats[num_sat].longitud, sf_color_white )
                elseif sgp_sats[num_sat].eclipsado then
                    SF_drawLineMap(lat_ant, lon_ant, sgp_sats[num_sat].latitud,sgp_sats[num_sat].longitud, sf_palette[12] )
                else
                    SF_drawLineMap(lat_ant, lon_ant, sgp_sats[num_sat].latitud,sgp_sats[num_sat].longitud, sf_palette[4] )
                end
            else
                if sgp_sats[num_sat].visible then
                    SF_drawLineMap(lat_ant, lon_ant, sgp_sats[num_sat].latitud,sgp_sats[num_sat].longitud, sf_color_white )
                elseif sgp_sats[num_sat].eclipsado then
                    SF_drawLineMap(lat_ant, lon_ant, sgp_sats[num_sat].latitud,sgp_sats[num_sat].longitud, sf_palette[12] )
                else
                    SF_drawLineMap(lat_ant, lon_ant, sgp_sats[num_sat].latitud,sgp_sats[num_sat].longitud, sf_palette[4] )
                end
            end
        end
        lat_ant = sgp_sats[num_sat].latitud
        lon_ant = sgp_sats[num_sat].longitud
    end

    SGP_calculateSun (jtime-const_julian_minute)
    SGP_calculateSatellite (num_sat , jtime-const_julian_minute)
    SGP_calculateSun (jtime)
    SGP_calculateSatellite (num_sat , jtime)
end




function SF_drawPoliLine (x, y, points, color)
    local i
    for i = 1,points-1 do
        draw.line( x[i]*480/720, y[i]*272/360, x[i+1]*480/720, y[i+1]*272/360, color)
    end
end

function SF_erase(x, y, caracteres)
    draw.fillrect(x, y, 8*caracteres, 8, sf_color_black)
end

function SF_initTails()
    -- Estelas satelites
    sf_sat_tails = {}
    local i
    for i = 1, sgp_sat_number do
        sf_sat_tails[i] = {}
        sf_sat_tails[i].step_current = 0
        sf_sat_tails[i].marca_tiempo = 0.0
        for j = 1, sf_palette_len do
            sf_sat_tails[i][j] = {}
            sf_sat_tails[i][j].azimut = 0
            sf_sat_tails[i][j].elevacion = -1
            sf_sat_tails[i][j].eclipsado = false
        end
        SF_initTail(i)
    end
end

function SF_changePalette(red, green, blue)
    local i
    for i = 1 , sf_palette_len do
        sf_palette[i] = color.new(red * (1-((i-1)/sf_palette_len)), green * (1-((i-1)/sf_palette_len)), blue * (1-((i-1)/sf_palette_len)))
    end
end

function SF_initTail(sat)
    SGP_getCurrentTime()
    jtime = sgp_time.ujtime

    SGP_calculateSun (jtime)
    SGP_calculateSatellite (sat , jtime)

    if sgp_sats[sat].elevacion < sf_sky.elevacion_minima then
        return
    end

    local step = const_julian_minute / sf_tail_length
    local jt = jtime
    local j
    for j = 1, sf_tail_length do
        SGP_calculateSun (jt)
        SGP_calculateSatellite (sat , jt)

        sf_sat_tails[sat][j].azimut = sgp_sats[sat].azimut
        sf_sat_tails[sat][j].elevacion = sgp_sats[sat].elevacion
        sf_sat_tails[sat][j].eclipsado = sgp_sats[sat].eclipsado
        jt = jt - step
    end

    SGP_calculateSun (jtime-const_julian_minute)
    SGP_calculateSatellite (sat , jtime-const_julian_minute)
    SGP_calculateSun (jtime)
    SGP_calculateSatellite (sat , jtime)
    sf_sat_tails[sat].marca_tiempo = jtime

end

function SF_redrawTails()
    local i
    for i = 1, sgp_sat_number do
        SF_initTail(i)
    end
end


function SF_resetTails()
    local i
    for i = 1, sgp_sat_number do
        SF_resetTail(i)
    end
end

function SF_resetTail(sat)
    if sf_sat_tails[sat][1].elevacion == -1 then
        return
    end

    sf_sat_tails[sat].step_current = 0
    sf_sat_tails[sat].marca_tiempo = 0.0
    local j
    for j = 1, sf_tail_length do
        sf_sat_tails[sat][j].azimut = 0
        sf_sat_tails[sat][j].elevacion = -1
        sf_sat_tails[sat][j].eclipsado = false
    end
end

function SF_AddPointToTail( num_sat, azimut, elevacion, eclipsado)
    local i = sf_tail_length - 1;

    if sgp_time.ujtime - sf_sat_tails[num_sat].marca_tiempo > const_julian_minute then
        screen.print(140,135,"Actualizando satelites...",sf_palette[8])
        screen.waitvblankstart()
        screen.flip()
        screen.print(140,135,"Actualizando satelites...",sf_palette[8])
        screen.waitvblankstart()
        screen.flip()
        SF_redrawTails()
    else
        while i > 0 do
            sf_sat_tails[num_sat][i+1].azimut = sf_sat_tails[num_sat][i].azimut
            sf_sat_tails[num_sat][i+1].elevacion = sf_sat_tails[num_sat][i].elevacion
            sf_sat_tails[num_sat][i+1].eclipsado = sf_sat_tails[num_sat][i].eclipsado
            i = i - 1
        end
        sf_sat_tails[num_sat][1].azimut = azimut
        sf_sat_tails[num_sat][1].elevacion = elevacion
        sf_sat_tails[num_sat][1].eclipsado = eclipsado
        sf_sat_tails[num_sat].marca_tiempo = sgp_time.ujtime
    end
end

function SND_azimut(azimut, elevacion)
    if elevacion > 80 then
        SND_wait("UP.wav",azimut, elevacion)
    else
        if ((0 <= azimut) and (azimut < 22.5 )) then
            SND_wait("N.wav",azimut, elevacion)
        elseif ((22.5 <= azimut) and (azimut < 67.5)) then
            SND_wait("NE.wav",azimut, elevacion)
        elseif ((67.5 <= azimut) and (azimut < 112.5)) then
            SND_wait("E.wav",azimut, elevacion)
        elseif ((112.5 <= azimut) and (azimut < 157.5)) then
            SND_wait("SE.wav",azimut, elevacion)
        elseif ((157.5 <= azimut) and (azimut < 202.5)) then
            SND_wait("S.wav",azimut, elevacion)
        elseif ((202.5 <= azimut) and (azimut < 247.5)) then
            SND_wait("SW.wav",azimut, elevacion)
        elseif ((247.5 <= azimut) and (azimut < 292.5)) then
            SND_wait("W.wav",azimut, elevacion)
        elseif ((292.5 <= azimut) and (azimut < 337.5)) then
            SND_wait("NW.wav",azimut, elevacion)
        elseif ((337.5 <= azimut) and (azimut < 360)) then
            SND_wait("N.wav",azimut, elevacion)
        end
    end
end

function SF_azimutToString(azimut)
    if ((0 <= azimut) and (azimut < 22.5 )) then
        return "N "
    elseif ((22.5 <= azimut) and (azimut < 67.5)) then
        return "NE"
    elseif ((67.5 <= azimut) and (azimut < 112.5)) then
        return "E "
    elseif ((112.5 <= azimut) and (azimut < 157.5)) then
        return "SE"
    elseif ((157.5 <= azimut) and (azimut < 202.5)) then
        return "S "
    elseif ((202.5 <= azimut) and (azimut < 247.5)) then
        return "SW"
    elseif ((247.5 <= azimut) and (azimut < 292.5)) then
        return "W "
    elseif ((292.5 <= azimut) and (azimut < 337.5)) then
        return "NW"
    elseif ((337.5 <= azimut) and (azimut < 360)) then
        return "N "
    end
end

function SND_wait( wave_file, azimut, elevacion)
    local snd = sound.load (wave_file,false)
    local voice = snd:play()
    voice:volume(255)
    local timer = timer.new()

    timer:reset(0)
    timer:start()

    if azimut ~= nil and elevacion ~= nil then
        SF_drawCrossSky(azimut, elevacion)
    end
    while timer:time() < 200 or voice:playing() do
        screen.waitvblankstart(5)
        screen.flip()
    end
    timer:stop()

end

function SND_playSoundsIfNeeded()
    if sf_primer_calculo then
        sf_elevacion_max_ant = sf_elevacion_max
        sf_noche_ant = sgp_location.noche
        sf_sun_elev_ant = sgp_sun.ele
        sf_moon_elev_ant = sgp_moon.ele
    else
        if sf_sun_elev_ant < -3 and sgp_sun.ele > -3 then
            SND_wait("sunrise.wav", nil, nil)
        end
        if sf_sun_elev_ant > 3 and sgp_sun.ele < 3 then
            SND_wait("sunset.wav", nil, nil)
        end
        if sf_sun_elev_ant < 0 and sgp_sun.ele > 0 then
            SND_wait("sunrise.wav", nil, nil)
            SGP_calculateSunRaiseTime()
            SGP_calculateSunSetTime()
        end
        if sf_sun_elev_ant > 0 and sgp_sun.ele < 0 then
            SND_wait("sunset.wav", nil, nil)
            SGP_calculateSunRaiseTime()
            SGP_calculateSunSetTime()
        end
        if sf_moon_elev_ant < -3 and sgp_moon.ele > -3 then
            SND_wait("moonrise.wav", nil, nil)
        end
        if sf_moon_elev_ant > 3 and sgp_moon.ele < 3 then
            SND_wait("moonset.wav", nil, nil)
        end
        if sf_moon_elev_ant < 0 and sgp_moon.ele > 0 then
            SND_wait("moonrise.wav", nil, nil)
            SGP_calculateMoonRaiseTime()
            SGP_calculateMoonSetTime()
        end
        if sf_moon_elev_ant > 0 and sgp_moon.ele < 0 then
            SND_wait("moonset.wav", nil, nil)
            SGP_calculateMoonRaiseTime()
            SGP_calculateMoonSetTime()
        end
        sf_sun_elev_ant = sgp_sun.ele
        sf_moon_elev_ant = sgp_moon.ele
        if sgp_location.noche and not sf_noche_ant then
            SND_wait("night_start.wav", nil, nil)
            SGP_calculateNightBegining()
            SGP_calculateNightEnding()
            sf_vision_nocturna = true
            SF_changePalette (sf_color_night.r,sf_color_night.g,sf_color_night.b)
        elseif not sgp_location.noche and sf_noche_ant then
            SND_wait("night_end.wav", nil, nil)
            SGP_calculateNightBegining()
            SGP_calculateNightEnding()
            sf_vision_nocturna = false
            SF_changePalette (sf_color_day.r,sf_color_day.g,sf_color_day.b)
        end
        sf_noche_ant = sgp_location.noche
        if sf_elevacion_max_ant < 80 and sf_elevacion_max > 80 then
            SND_wait("90.wav", sf_azimut_max, sf_elevacion_max)
            SND_azimut(sf_azimut_max, sf_elevacion_max)
        elseif sf_elevacion_max_ant < 60 and sf_elevacion_max > 60 then
            SND_wait("60.wav", sf_azimut_max, sf_elevacion_max)
            SND_azimut(sf_azimut_max, sf_elevacion_max)
        elseif sf_elevacion_max_ant < 30 and sf_elevacion_max > 30 then
            SND_wait("30.wav", sf_azimut_max, sf_elevacion_max)
            SND_azimut(sf_azimut_max, sf_elevacion_max)
        elseif sf_elevacion_max_ant < sf_sky.elevacion_minima and sf_elevacion_max > sf_sky.elevacion_minima then
            SND_wait("00.wav", sf_azimut_max, sf_elevacion_max)
            SND_azimut(sf_azimut_max, sf_elevacion_max)
        end
        sf_elevacion_max_ant = sf_elevacion_max

    end

    if sf_pass_limit > 0 and sf_pass_current > 0 and sf_pass_current <= sf_pass_limit then
        if sf_current_jtime_ant < sf_passes[sf_pass_current].ini_jt and sf_current_jtime > sf_passes[sf_pass_current].ini_jt then
            SND_wait("iss_start.wav",sf_passes[sf_pass_current].ini_azimut, sf_passes[sf_pass_current].ini_elevacion)
            SND_azimut(sf_passes[sf_pass_current].ini_azimut, sf_passes[sf_pass_current].ini_elevacion)
        elseif sf_current_jtime_ant < sf_passes[sf_pass_current].max_jt and sf_current_jtime > sf_passes[sf_pass_current].max_jt then
            SND_wait("iss_max.wav",sf_passes[sf_pass_current].max_azimut, sf_passes[sf_pass_current].max_elevacion)
            SND_azimut(sf_passes[sf_pass_current].max_azimut, sf_passes[sf_pass_current].max_elevacion)
        elseif sf_current_jtime_ant < sf_passes[sf_pass_current].fin_jt and sf_current_jtime > sf_passes[sf_pass_current].fin_jt then
            SND_wait("iss_end.wav",sf_passes[sf_pass_current].fin_azimut, sf_passes[sf_pass_current].fin_elevacion)
            SND_azimut(sf_passes[sf_pass_current].fin_azimut, sf_passes[sf_pass_current].fin_elevacion)
        end
    end
end

-- AQUI EMPIEZAN LOS CALCULOS SGP





function SGP_Date_To_Julian(yr, mo, dy, hr, mi, se)
    return SGP_Julian_Date_of_Year(yr) + SGP_DOY(yr,mo,dy) + SGP_Fraction_of_Day(hr,mi,se)
end

function SGP_Julian_To_Date(jt)
        local day, month, year = SGP_calendarDate(jt,3)
        local hour, minutes, seconds, hundred_sec = SGP_timeOfDay(jt,3)
        return year, month, day, hour, minutes, seconds
end

function SGP_calendarDate(jd , res)
    local Z
    local month, day, year
    local A,B,C,D,E,F,alpha,factor


    factor = 0.5/const_secday/math.pow(10.0,res)
    F = (jd + 0.5) - math.floor(jd + 0.5)
    if (F + factor >= 1.0) then
        jd = jd + factor
        F = 0.0
    end

    Z = math.floor(jd + 0.5)
    if (Z < 2299161) then
        A = Z
    else
        alpha = math.floor((Z - 1867216.25)/36524.25)
        A = (Z + 1.0 + alpha) - math.floor(alpha/4.0)
    end

    B = A + 1524.0
    C = math.floor((B - 122.1)/365.25)
    D = math.floor(365.25 * C)
    E = math.floor((B - D)/30.6001)
    day = math.floor(B - D - math.floor(30.6001 * E) + F)
    if (E < 13.5) then
        month = math.floor((E - 1.0)+0.5)
    else
        month = math.floor((E - 13.0)+0.5)
    end
    if (month > 2.5) then
        year = math.floor((C - 4716.0)+0.5)
    else
        year = math.floor((C - 4715.0)+0.5)
    end

    return day, month , year
end

function SGP_timeOfDay(jd, res)
    local hr,mn,sec,hu
    local factor,time_,sc

    res = math.min(math.max(0.0,res),3.0)
    factor = math.pow(10.0,res)
    time_ = ((jd - 0.5)-math.floor(jd - 0.5))*const_secday
    time_ = math.floor(time_*factor+0.5)/factor
    hr = math.floor(time_/3600.0)
    time_ = time_ - (3600.0*hr)
    if (hr == 24) then
        hr = 0
    end
    mn = math.floor(time_/60.0)
    sc = time_ - (60.0*mn)

    hu = math.floor(((sc - math.floor(sc))*1000)+0.5)
    sec = math.floor(sc)

    return hr, mn, sec, hu
end

-- Calcula la fecha Juliana de Enero del año 0.0
function SGP_Julian_Date_of_Year(year)
  local Y = year - 1
  local A = math.floor(year/100)
  local B = 2 - A + math.floor(A/4)
  return math.floor(365.25 * Y) + math.floor(30.6001 * 14) + 1720994.5 + B
end

function SGP_Julian_Date_of_Epoch(epoch)
        local year
        local day

        year = math.floor(epoch*0.001)
        if year < 57 then
            year = year + 2000
        else
            year = year + 1900
        end
        day = ((epoch*0.001) - math.floor(epoch*0.001))*1000

        return  SGP_Julian_Date_of_Year(year) + day
end

function SGP_DOY(yr,mo,dy)
  local days = { 31,28,31,30,31,30,31,31,30,31,30,31 }
  local day = 0
  for i = 1,mo-1 do
    day = day + days[i]
  end
  day = day + dy
  if ((yr % 4) == 0) and (((yr % 100) ~= 0) or ((yr % 400) == 0)) and (mo > 2) then
    day = day + 1
  end
  return day
end

function SGP_Fraction_of_Day(hr,mi,se)
  return (hr + (mi + se/60)/60)/24
end



function SGP_isRepeated(s,catalog_num)
    local i = 1
    while i < s do
        if sgp_sats[i].catnr == catalog_num then
            --Actualizamos el satelite con los nuevos datos
            sgp_sats[i].catnr = sgp_sats[s].catnr
            sgp_sats[i].epoch = sgp_sats[s].epoch
            sgp_sats[i].julian_epoch = sgp_sats[s].julian_epoch
            sgp_sats[i].xndt2o = sgp_sats[s].xndt2o
            sgp_sats[i].xndd6o = sgp_sats[s].xndd6o
            sgp_sats[i].iexp = sgp_sats[s].iexp
            sgp_sats[i].bstar = sgp_sats[s].bstar
            sgp_sats[i].ibexp = sgp_sats[s].ibexp
            sgp_sats[i].elset = sgp_sats[s].elset

            sgp_sats[i].xincl = sgp_sats[s].xincl
            sgp_sats[i].xnodeo = sgp_sats[s].xnodeo
            sgp_sats[i].eo = sgp_sats[s].eo
            sgp_sats[i].omegao = sgp_sats[s].omegao
            sgp_sats[i].xmo = sgp_sats[s].xmo
            sgp_sats[i].xno = sgp_sats[s].xno

            sgp_sats[i].xndd6o = sgp_sats[s].xndd6o
            sgp_sats[i].bstar = sgp_sats[s].bstar
            sgp_sats[i].xnodeo = sgp_sats[s].xnodeo
            sgp_sats[i].omegao = sgp_sats[s].omegao
            sgp_sats[i].xmo = sgp_sats[s].xmo
            sgp_sats[i].xincl = sgp_sats[s].xincl
            sgp_sats[i].xno = sgp_sats[s].xno
            sgp_sats[i].xndt2o = sgp_sats[s].xndt2o
            sgp_sats[i].xndd6o = sgp_sats[s].xndd6o

            --Inicializa algunas variables
            sgp_sats[i].iflag = sgp_sats[s].iflag
            sgp_sats[i].primera_vez = sgp_sats[s].primera_vez
            sgp_sats[i].elevacion_ant = sgp_sats[s].elevacion_ant
            sgp_sats[i].no_calcular = sgp_sats[s].no_calcular

            return true
        else
            i = i + 1
        end
    end

    return false
end

function SGP_getLocationFromFile(filename)
    -- Miramos primero que el fichero exista
    local file = io.open(filename)
    if file then
        io.close(file)
    else
        return false
    end



    for line in io.lines(filename) do
        local str = string.sub(line,1,3)
        if str == "lat" then
            sgp_location.lat = tonumber(string.sub(line,5,string.len(line)))
        elseif str == "lon" then
            sgp_location.lon = tonumber(string.sub(line,5,string.len(line)))
        elseif str == "alt" then
            sgp_location.alt = tonumber(string.sub(line,5,string.len(line)))
        elseif str == "off" then
            sgp_location.UTC_offset = tonumber(string.sub(line,5,string.len(line)))
        elseif str == "nam" then
            sgp_location.name = string.sub(line,5,string.len(line))
        elseif str == "dst" then
            if ( string.sub(line,5,8) == "true" ) then
                sgp_location.dst = true
            else
                sgp_location.dst = false
            end
        end
    end

    sgp_location.polar.lat = math.rad(sgp_location.lat)
    sgp_location.polar.lon = math.rad(SGP_modulus(sgp_location.lon,360))
    sgp_location.polar.alt = sgp_location.alt * 0.001
    return true

end

function SGP_getStars(filename, mag)
    -- Miramos primero que el fichero exista
    local file = io.open(filename)
    if not file then
        return false
    end

    sgp_stars = {}
    sgp_stars2 = {}
    sgp_constellations = {}
    local i = 1
    local j = 1
    local sum_ra = 0
    local sum_dec = 0
    local line = file:read("*l")
    local primera_estrella = true
    while line do
        local str = string.sub(line,1,3)
        if tonumber(str) ~= nil then
            sgp_stars[i] = {}
            sgp_stars[i].id = tonumber(string.sub(line,1,4))
            sgp_stars[i].ra = tonumber(string.sub(line,6,13))*15
            sgp_stars[i].dec = tonumber(string.sub(line,15,23))
            sgp_stars[i].mag = tonumber(string.sub(line,25,29))
            sgp_stars[i].no_calcular = 0
            if sgp_stars[i].mag < mag then
                if primera_estrella then
                    primera_estrella = false
                else
                    local media = (sum_ra / (i - sgp_constellations[j-1].primero + 1))
                    if math.abs(media - sgp_stars[i].ra) > 250 then
                        if media > sgp_stars[i].ra then
                            sgp_stars[i].ra = sgp_stars[i].ra + 360.0
                        else
                            sgp_stars[i].ra = sgp_stars[i].ra - 360.0
                        end
                    end

                end

                sum_ra = sum_ra + sgp_stars[i].ra
                sum_dec = sum_dec + sgp_stars[i].dec + 90.0

                i = i + 1
            end
        else
            if j > 1 then
                sgp_constellations[j-1].ultimo = i-1
                sgp_constellations[j-1].label_ra = (sum_ra / (sgp_constellations[j-1].ultimo - sgp_constellations[j-1].primero+1))
                sgp_constellations[j-1].label_dec = (sum_dec / (sgp_constellations[j-1].ultimo - sgp_constellations[j-1].primero+1)) - 90.0
                sum_ra = 0
                sum_dec = 0
                primera_estrella = true
            end
            sgp_constellations[j] = {}
            sgp_constellations[j].nombre = string.sub(line,1,string.len(line)-1)
            sgp_constellations[j].no_calcular = 0
            sgp_constellations[j].primero = i
            j = j + 1
        end
        line = file:read("*l")
    end
    file:close()
    sgp_star_number = i - 1
    sgp_constellation_number = j-1
    sgp_constellations[sgp_constellation_number].ultimo = sgp_star_number
    sgp_constellations[sgp_constellation_number].label_ra = sum_ra / (sgp_constellations[sgp_constellation_number].ultimo - sgp_constellations[sgp_constellation_number].primero + 1)
    sgp_constellations[sgp_constellation_number].label_dec = sum_dec / (sgp_constellations[sgp_constellation_number].ultimo - sgp_constellations[sgp_constellation_number].primero + 1)

    return true
end



function SGP_getTLE(filename)
    if sgp_sat_number < 0 then
        return
    end

    -- Miramos primero que el fichero exista
    local file = io.open(filename)
    if file then
        io.close(file)
    else
        sgp_sat_number = -2
        return
    end

    local sat_number = sgp_sat_number + 1
    local line_number = 1
    for line in io.lines(filename) do
        if line_number % 3 == 1 then
            -- Obtiene nombre y guarda los numeros de la estacion espacial y el shuttle
            --SL-16 R/B

            sgp_sats[sat_number] = { }
            sgp_sats[sat_number].numero = sat_number
            sgp_sats[sat_number].nombre = string.sub(line,1,24)

        elseif line_number % 3 == 2 then
            -- Obtiene primera linea
            --1 23405U 94077B   07216.52870987 -.00000029  00000-0  10000-4 0  7954
            if string.sub(line,1,2) == "1 " then
                if line:len() >= 69 then
                    sgp_sats[sat_number].catnr = string.sub(line,3,7)
                    sgp_sats[sat_number].epoch = tonumber(string.sub(line,19,32))
                    sgp_sats[sat_number].julian_epoch = SGP_Julian_Date_of_Epoch(sgp_sats[sat_number].epoch)
                    sgp_sats[sat_number].xndt2o = tonumber(string.sub(line,34,43))
                    sgp_sats[sat_number].xndd6o = tonumber(string.sub(line,45,50)) * 0.00001
                    sgp_sats[sat_number].iexp = tonumber(string.sub(line,51,52))
                    sgp_sats[sat_number].bstar = tonumber(string.sub(line,54,59)) * 0.00001
                    sgp_sats[sat_number].ibexp = tonumber(string.sub(line,60,61))
                    sgp_sats[sat_number].elset = string.sub(line,66,69)
                else
                    sgp_sat_number = -1
                    return
                end
            else
                -- Suponer que se trata de la linea de nombre

                sgp_sats[sat_number] = { }
                sgp_sats[sat_number].numero = sat_number
                sgp_sats[sat_number].nombre = string.sub(line,1,24)
                line_number = line_number - 1

            end
        elseif line_number % 3 == 0 then
            -- Obtiene seguntda linea
            --2 23405  70.9690 232.0909 0004094 343.0355  17.0620 14.14891027655607

            if string.sub(line,1,2) == "2 " then
                if line:len() >= 69 then
                    sgp_sats[sat_number].xincl = tonumber(string.sub(line,9,16))
                    sgp_sats[sat_number].xnodeo = tonumber(string.sub(line,18,25))
                    sgp_sats[sat_number].eo = tonumber(string.sub(line,27,33)) * 0.0000001
                    sgp_sats[sat_number].omegao = tonumber(string.sub(line,35,40))
                    sgp_sats[sat_number].xmo = tonumber(string.sub(line,44,51))
                    sgp_sats[sat_number].xno = tonumber(string.sub(line,53,63))


                    sgp_sats[sat_number].xndd6o = sgp_sats[sat_number].xndd6o * math.pow(10.0,sgp_sats[sat_number].iexp)
                    sgp_sats[sat_number].bstar = (sgp_sats[sat_number].bstar * math.pow(10.0,sgp_sats[sat_number].ibexp)) / const_ae
                    sgp_sats[sat_number].xnodeo = math.rad(sgp_sats[sat_number].xnodeo)
                    sgp_sats[sat_number].omegao = math.rad(sgp_sats[sat_number].omegao)
                    sgp_sats[sat_number].xmo = math.rad(sgp_sats[sat_number].xmo)
                    sgp_sats[sat_number].xincl = math.rad(sgp_sats[sat_number].xincl)
                    sgp_sats[sat_number].xno = (sgp_sats[sat_number].xno * (math.pi*2.0))/const_xmnpda
                    sgp_sats[sat_number].xndt2o = (sgp_sats[sat_number].xndt2o * (math.pi*2.0))/const_xmnpda^2
                    sgp_sats[sat_number].xndd6o = (sgp_sats[sat_number].xndd6o * (math.pi*2.0))/const_xmnpda^3

                    --Inicializa algunas variables
                    sgp_sats[sat_number].iflag = true
                    sgp_sats[sat_number].primera_vez = true
                    sgp_sats[sat_number].elevacion_ant = 0
                    sgp_sats[sat_number].no_calcular = 0

                    if not SGP_isRepeated(sat_number, sgp_sats[sat_number].catnr) then
                        local cadena = string.sub(sgp_sats[sat_number].nombre,1,3)
                        if cadena == "ISS" then
                            sf_iss = sat_number
                            sf_selected_sat = sf_iss
                        end
                        sat_number = sat_number + 1
                    end
                else
                    sgp_sat_number = -1
                    return
                end
            else
                -- Suponer que se trata de la linea de nombre

                sgp_sats[sat_number] = { }
                sgp_sats[sat_number].numero = sat_number
                sgp_sats[sat_number].nombre = string.sub(line,1,24)
                line_number = line_number - 2

            end
        end

        line_number = line_number + 1
    end
    sgp_sat_number = sat_number - 1
end

function SGP_modulus( d1, d2)
    local modu

    modu = d1 - (math.floor(d1/d2) * d2)
    if modu >= 0 then
        return modu
    else
        return modu + d2
    end
end


function SGP_fmod2p( d )
    return SGP_modulus(d,(math.pi * 2.0))
end


function SGP_acTan(sinx,cosx)
    if cosx == 0 then
        if sinx > 0 then
            return (math.pi / 2.0)
        else
            return (3.0 * math.pi / 2.0)
        end
    else
        if cosx > 0 then
            return math.atan( sinx / cosx )
        else
            return math.pi + math.atan( sinx / cosx )
        end
    end
end



function SGP_deltaET (year)
    return (26.465 + 0.747622 * (year - 1950) + 1.886913 * math.sin((math.pi * 2.0) * (year - 1975.0) / 33.0))
end

function SGP_thetaG_JD( jd )

    local  UT,TU,GMST

    UT = (jd + 0.5) - math.floor(jd + 0.5)
    jd = jd - UT
    TU = (jd - 2451545.0)/36525
    GMST = 24110.54841 + TU * (8640184.812866 + TU * (0.093104 - TU * 6.2 * 0.000001))
    GMST = SGP_modulus(GMST + const_secday * const_omega_E * UT,const_secday)
    return ((math.pi*2.0) * GMST/const_secday)
end



function SGP_magnitud( x,y,z )
        return math.sqrt(x^2 + y^2 + z^2)
end

function SGP_subVectores(v1, v2)
    local v3 = { }
    v3.x = v1.x - v2.x
    v3.y = v1.y - v2.y
    v3.z = v1.z - v2.z
    v3.m = SGP_magnitud(v3.x,v3.y,v3.z)
    return v3
end

-- Calcula el angulo comprendido entre los vectores v1 y v2
function SGP_angulo(v1, v2)
    v1.m = SGP_magnitud(v1.x,v1.y,v1.z)
    v2.m = SGP_magnitud(v2.x,v2.y,v2.z)
    return math.acos(SGP_dot(v1,v2)/(v1.m * v2.m))
end

function SGP_dot(v1, v2)
    return v1.x * v2.x + v1.y * v2.y + v1.z * v2.z
end


function SGP_calculateSatPosVel( sat , jtime )
    local i
    local cosuk,sinuk,rfdotk,vx,vy,vz,ux,uy,uz,xmy,xmx
    local cosnok,sinnok,cosik,sinik,rdotk,xinck,xnodek,uk,rk
    local cos2u,sin2u,u,sinu,cosu,betal,rfdot,rdot,r,pl,elsq
    local esine,ecose,epw,temp6,temp5,temp4,temp3,cosepw,sinepw
    local capu,ayn,xlt,aynl,xll,axn,xn,beta,xl,e,a,tfour,temp2
    local tcube,delm,delomg,templ,tempe,tempa,xnode,tsq,xmp,temp
    local omega,xnoddf,omgadf,xmdf,x,y,z,xdot,ydot,zdot,temp1

    local tsince = (jtime - sat.julian_epoch) * const_xmnpda

    -- Recover original mean motion (xnodp) and semimajor axis (aodp)
    -- from input elements.
    if sat.iflag then
        -- Initialization
        sat.a1 = math.pow(const_xke/sat.xno,const_tothrd)
        sat.cosio = math.cos(sat.xincl)
        sat.theta2 = sat.cosio^2
        sat.x3thm1 = (3.0 * sat.theta2) - 1.0
        sat.eosq = sat.eo^2
        sat.betao2 = 1.0 - sat.eosq
        sat.betao = math.sqrt(sat.betao2)
        sat.del1 = 1.5 * const_ck2 * sat.x3thm1 / (sat.a1 * sat.a1 * sat.betao * sat.betao2)
        sat.ao = sat.a1 * (1.0 - sat.del1 * (0.5 * const_tothrd + sat.del1 * (1.0 + 134.0 / 81.0 * sat.del1)))
        sat.delo = 1.5 * const_ck2 * sat.x3thm1 / (sat.ao * sat.ao * sat.betao * sat.betao2)
        sat.xnodp = sat.xno / (1.0 + sat.delo)
        sat.aodp = sat.ao / (1.0 - sat.delo)

        -- For perigee less than 220 kilometers, the isimp flag is set and
        -- the equations are truncated to linear variation in sqrt a and
        -- quadratic variation in mean anomaly.  Also, the c3 term, the
        -- delta omega term, and the delta m term are dropped.

        sat.isimp = 0
        if ((sat.aodp*(1.0 - sat.eo)/const_ae) < (220.0/const_xkmper + const_ae)) then
            sat.isimp = 1
        end
        -- For perigee below 156 km, the values of s and qoms2t are altered.

        sat.s4 = const_s
        sat.qoms24 = const_qoms2t
        sat.perige = (sat.aodp * (1.0 - sat.eo) - const_ae)*const_xkmper
        if sat.perige < 156.0 then
            sat.s4 = sat.perige - 78.0
            if sat.perige <= 98.0 then
                sat.s4 = 20.0
            end
            sat.qoms24 = math.pow((120.0 - sat.s4) * const_ae / const_xkmper , 4.0)
            sat.s4 = sat.s4 / const_xkmper + const_ae
        end

        sat.pinvsq = 1.0 / (sat.aodp * sat.aodp * sat.betao2 * sat.betao2)
        sat.tsi = 1.0/(sat.aodp - sat.s4)
        sat.eta = sat.aodp * sat.eo * sat.tsi
        sat.etasq = sat.eta * sat.eta
        sat.eeta = sat.eo * sat.eta
        sat.psisq = math.abs(1.0 - sat.etasq)
        sat.coef = sat.qoms24 * math.pow(sat.tsi,4.0)
        sat.coef1 = sat.coef / math.pow(sat.psisq,3.5)
        sat.c2 = sat.coef1 * sat.xnodp * (sat.aodp * (1.0 + 1.5 * sat.etasq + sat.eeta * (4.0 + sat.etasq))
            + 0.75 * const_ck2 * sat.tsi/sat.psisq * sat.x3thm1 * (8.0 + 3.0 * sat.etasq * (8.0 + sat.etasq)))
        sat.c1 = sat.bstar * sat.c2
        sat.sinio = math.sin(sat.xincl)
        sat.a3ovk2 = (-const_xj3) / const_ck2 * math.pow(const_ae,3.0)
        sat.c3 = sat.coef * sat.tsi * sat.a3ovk2 * sat.xnodp * const_ae * sat.sinio / sat.eo
        sat.x1mth2 = 1.0 - sat.theta2
        sat.c4 = 2.0 * sat.xnodp * sat.coef1 * sat.aodp * sat.betao2 * (sat.eta * (2.0 + 0.5 * sat.etasq)
            + sat.eo * (0.5 + 2.0 * sat.etasq) - 2.0 * const_ck2 * sat.tsi/(sat.aodp * sat.psisq)
             * (-3.0 * sat.x3thm1 * (1.0 - 2.0 * sat.eeta + sat.etasq * (1.5 - 0.5 * sat.eeta))
            + 0.75 * sat.x1mth2 * (2.0 * sat.etasq - sat.eeta * (1.0 + sat.etasq)) * math.cos(2.0 * sat.omegao)))
        sat.c5 = 2.0 * sat.coef1 * sat.aodp * sat.betao2 * (1.0 + 2.75 * (sat.etasq + sat.eeta) + sat.eeta * sat.etasq)
        sat.theta4 = sat.theta2 * sat.theta2
        local temp1 = 3.0 * const_ck2 * sat.pinvsq * sat.xnodp
        local temp2 = temp1 * const_ck2 * sat.pinvsq
        local temp3 = 1.25 * const_ck4 * sat.pinvsq * sat.pinvsq * sat.xnodp
        sat.xmdot = sat.xnodp + 0.5 * temp1 * sat.betao * sat.x3thm1
            + 0.0625 * temp2 * sat.betao * (13.0 - 78.0 * sat.theta2 + 137.0 * sat.theta4)
        sat.x1m5th = 1.0 - 5.0 * sat.theta2
        sat.omgdot = -0.5 * temp1 * sat.x1m5th + 0.0625 * temp2 * (7.0 - 114.0 * sat.theta2 +395.0 * sat.theta4)
            + temp3 * (3.0 - 36.0 * sat.theta2 + 49.0 * sat.theta4)
        sat.xhdot1 = -temp1 * sat.cosio
        sat.xnodot = sat.xhdot1 + (0.5 * temp2 * (4.0 - 19.0 * sat.theta2)
            + 2.0 * temp3 * (3.0 - 7.0 * sat.theta2)) * sat.cosio
        sat.omgcof = sat.bstar * sat.c3 * math.cos(sat.omegao)
        sat.xmcof = -const_tothrd * sat.coef * sat.bstar * const_ae/sat.eeta
        sat.xnodcf = 3.5 * sat.betao2 * sat.xhdot1 * sat.c1
        sat.t2cof = 1.5 * sat.c1
        sat.xlcof = 0.125 * sat.a3ovk2 * sat.sinio * (3.0 + 5.0 * sat.cosio)/(1.0 + sat.cosio)
        sat.aycof = 0.25 * sat.a3ovk2 * sat.sinio
        sat.delmo = math.pow(1.0 + sat.eta * math.cos(sat.xmo),3.0)
        sat.sinmo = math.sin(sat.xmo)
        sat.x7thm1 = 7.0 * sat.theta2 - 1.0
        if sat.isimp ~= 1 then
            sat.c1sq = sat.c1 * sat.c1
            sat.d2 = 4.0 * sat.aodp * sat.tsi * sat.c1sq
            local temp = sat.d2 * sat.tsi * sat.c1/3.0
            sat.d3 = (17.0 * sat.aodp + sat.s4) * temp
            sat.d4 = 0.5 * temp * sat.aodp * sat.tsi * (221.0 * sat.aodp + 31.0 * sat.s4) * sat.c1
            sat.t3cof = sat.d2 + 2.0 * sat.c1sq
            sat.t4cof = 0.25 * (3.0 * sat.d3 + sat.c1 * (12.0 * sat.d2 + 10.0 * sat.c1sq))
            sat.t5cof = 0.2 * (3.0 * sat.d4 + 12.0 * sat.c1 * sat.d3 + 6.0 * sat.d2 * sat.d2 + 15.0 * sat.c1sq * (2.0 * sat.d2 + sat.c1sq))
        end
        sat.iflag = 0
    end
    --Update for secular gravity and atmospheric drag.

    xmdf = sat.xmo + sat.xmdot * tsince
    omgadf = sat.omegao + sat.omgdot * tsince
    xnoddf = sat.xnodeo + sat.xnodot * tsince
    omega = omgadf
    xmp = xmdf
    tsq = tsince * tsince
    xnode = xnoddf + sat.xnodcf * tsq
    tempa = 1.0 - sat.c1 * tsince
    tempe = sat.bstar * sat.c4 * tsince
    templ = sat.t2cof * tsq
    if not sat.isimp == 1 then
        delomg = sat.omgcof * tsince
        delm = sat.xmcof * (math.pow(1.0 + sat.eta * math.cos(xmdf),3.0) - sat.delmo)
        temp = delomg + delm
        xmp = xmdf + temp
        omega = omgadf - temp
        tcube = tsq * tsince
        tfour = tsince * tcube
        tempa = tempa - sat.d2 * tsq - sat.d3 * tcube - sat.d4 * tfour
        tempe = tempe + sat.bstar * sat.c5 * (math.sin(xmp) - sat.sinmo)
        templ = templ + sat.t3cof * tcube + tfour * (sat.t4cof + tsince * sat.t5cof)
    end
    a = sat.aodp * tempa * tempa
    e = sat.eo - tempe
    xl = xmp + omega + xnode + sat.xnodp * templ
    beta = math.sqrt(1.0 - e * e)
    xn = const_xke/math.pow(a,1.5)

    --Long period periodics
    axn = e * math.cos(omega)
    temp = 1.0/(a * beta * beta)
    xll = temp * sat.xlcof * axn
    aynl = temp * sat.aycof
    xlt = xl + xll
    ayn = e * math.sin(omega) + aynl

    -- Solve Kepler's Equation
    capu = SGP_fmod2p(xlt - xnode)
    i = 1
    epw = 0
    repeat
        i = i + 1
        if i == 2 then -- Primera iteración
            temp2 = capu
        else
            temp2 = epw
        end
        sinepw = math.sin(temp2)
        cosepw = math.cos(temp2)
        temp3 = axn * sinepw
        temp4 = ayn * cosepw
        temp5 = axn * cosepw
        temp6 = ayn * sinepw
        epw = (capu - temp4 + temp3 - temp2)/(1.0 - temp5 - temp6) + temp2
    until ((math.abs(epw - temp2) <= const_e6a) or (i>10))

    --Short period preliminary quantities

    ecose = temp5 + temp6
    esine = temp3 - temp4
    elsq = axn * axn + ayn * ayn
    temp = 1.0 - elsq
    pl = a * temp
    r = a * (1.0 - ecose)
    temp1 = 1.0/r
    rdot = const_xke * math.sqrt(a) * esine * temp1
    rfdot = const_xke * math.sqrt(pl) * temp1
    temp2 = a * temp1
    betal = math.sqrt(temp)
    temp3 = 1.0/(1.0 + betal)
    cosu = temp2 * (cosepw - axn + ayn * esine * temp3)
    sinu = temp2 * (sinepw - ayn - axn * esine * temp3)
    u = SGP_acTan(sinu,cosu)
    sin2u = 2.0 * sinu * cosu
    cos2u = 2.0 * cosu * cosu - 1.0
    temp = 1.0/pl
    temp1 = const_ck2 * temp
    temp2 = temp1 * temp
    --Update for short periodics
    rk = r * (1.0 - 1.5 * temp2 * betal * sat.x3thm1) + 0.5 * temp1 * sat.x1mth2 * cos2u
    uk = u - 0.25 * temp2 * sat.x7thm1 * sin2u
    xnodek = xnode + 1.5 * temp2 * sat.cosio * sin2u
    xinck = sat.xincl + 1.5 * temp2 * sat.cosio * sat.sinio * cos2u
    rdotk = rdot - xn * temp1 * sat.x1mth2 * sin2u
    rfdotk = rfdot + xn * temp1 * (sat.x1mth2 * cos2u + 1.5 * sat.x3thm1)
    --Orientation vectors
    sinuk = math.sin(uk)
    cosuk = math.cos(uk)
    sinik = math.sin(xinck)
    cosik = math.cos(xinck)
    sinnok = math.sin(xnodek)
    cosnok = math.cos(xnodek)
    xmx = -sinnok * cosik
    xmy = cosnok * cosik
    ux = xmx * sinuk + cosnok * cosuk
    uy = xmy * sinuk + sinnok * cosuk
    uz = sinik * sinuk
    vx = xmx * cosuk - cosnok * sinuk
    vy = xmy * cosuk - sinnok * sinuk
    vz = sinik * cosuk

    --Position and velocity
    x = rk * ux
    sat.x = x
    y = rk * uy
    sat.y = y
    z = rk * uz
    sat.z = z
    xdot = rdotk * ux + rfdotk * vx
    sat.vx = xdot
    ydot = rdotk * uy + rfdotk * vy
    sat.vy = ydot
    zdot = rdotk * uz + rfdotk * vz
    sat.vz = zdot

    --Convert sat state

    sat.x = sat.x * const_xkmper
    sat.vx = sat.vx * const_xkmper/60
    sat.y = sat.y * const_xkmper
    sat.vy = sat.vy * const_xkmper/60
    sat.z = sat.z * const_xkmper
    sat.vz = sat.vz * const_xkmper/60

    sat.m = math.sqrt(sat.x^2+sat.y^2+sat.z^2)
    sat.vm = math.sqrt(sat.vx^2+sat.vy^2+sat.vz^2)

end


function SGP_calculateSatIllum(sat)
    local sd_sun , sd_earth
    local delta
    local rho
    local earth

    -- Determina eclipse parcial
    sd_earth = math.asin(const_xkmper/sat.m)
    rho = SGP_subVectores(sgp_sun,sat)
    sd_sun = math.asin(const_sr/rho.m)
    earth = { }
    earth.x = -sat.x
    earth.y = -sat.y
    earth.z = -sat.z
    earth.m = sat.m
    delta = SGP_angulo(sgp_sun,earth)
    sat.depth = sd_earth - sd_sun - delta
    if sd_earth < sd_sun then
        sat.eclipsado = false
    else
        if sat.depth >= 0 then
          sat.eclipsado = true
        else
          sat.eclipsado = false
        end
    end
end


function SGP_calculateSatLatLonAlt (sat, jtime)
    local alt, lon, lat
    local theta, r, e2, phi, c

    theta = SGP_acTan(sat.y , sat.x)
    lon = SGP_modulus(theta - SGP_thetaG_JD(jtime),math.pi*2.0)
    r = math.sqrt(sat.x^2 + sat.y^2)
    e2 = const_f*(2.0 - const_f)
    lat = SGP_acTan(sat.z,r)
    repeat
        phi = lat
        c = 1.0/math.sqrt(1.0 - e2* math.pow(math.sin(phi),2.0))
        lat = SGP_acTan(sat.z + const_xkmper * c * e2 * math.sin(phi),r)
    until (math.abs(lat-phi) < 0.0000000001)

    alt = r/math.cos(lat) - const_xkmper * c

    sat.latitud = math.deg(lat)
    sat.longitud = math.deg(lon)
    sat.altitud = alt
    if (sat.longitud >= 180) then
        sat.longitud = sat.longitud - 360
    end
end

function SGP_calculateSun (jtime)
    SGP_calculateSunPosition( jtime )
    SGP_calculateLocation( jtime )
    SGP_calculateSunAzElev( jtime )
end

function SGP_calculateSunPosition(jtime)

    local mjd,year,T,M,L,e,C,O,Lsa,nu,R,eps
    local alt, lon, lat
    local thetaAux, r, e2, phi, c2

    mjd = jtime - 2415020.0
    year = 1900.0 + mjd/365.25
    T = (mjd + SGP_deltaET(year)/const_secday)/36525.0
    M = math.rad(SGP_modulus(358.47583 + SGP_modulus(35999.04975 * T,360.0) - (0.000150 + 0.0000033*T)*(T*T),360.0))
    L = math.rad(SGP_modulus(279.69668 + SGP_modulus(36000.76892*T,360.0) + 0.0003025*(T*T),360.0))
    e = 0.01675104 - (0.0000418 + 0.000000126*T)*T
    C = math.rad((1.919460 - (0.004789 + 0.000014*T)*T)*math.sin(M) + (0.020094 - 0.000100*T)*math.sin(2.0*M) + 0.000293*math.sin(3.0*M))
    O = math.rad(SGP_modulus(259.18 - 1934.142*T,360.0))
    Lsa = SGP_modulus(L + C - math.rad(0.00569 - 0.00479*math.sin(O)),(math.pi*2.0))
    nu = SGP_modulus(M + C,(math.pi*2.0))
    R = 1.0000002*(1.0 - (e*e))/(1.0 + e*math.cos(nu))
    eps = math.rad(23.452294 - (0.0130125 + (0.00000164 - 0.000000503*T)*T)*T + 0.00256*math.cos(O))
    R = const_AU*R


    sgp_sun.x = R*math.cos(Lsa)
    sgp_sun.y = R*math.sin(Lsa)*math.cos(eps)
    sgp_sun.z = R*math.sin(Lsa)*math.sin(eps)
    sgp_sun.m = R


    thetaAux = SGP_acTan(sgp_sun.y,sgp_sun.x)
    lon = SGP_modulus(thetaAux - SGP_thetaG_JD(jtime),math.pi*2.0)
    r = math.sqrt(sgp_sun.x^2 + sgp_sun.y^2)
    e2 = const_f*(2.0 - const_f)
    lat = SGP_acTan(sgp_sun.z,r)
    repeat
        phi = lat
        c2 = 1.0 / math.sqrt (1.0 - e2 * math.pow(math.sin(phi),2.0))
        lat = SGP_acTan(sgp_sun.z + const_xkmper*c2*e2*math.sin(phi),r)
    until (math.abs(lat-phi) < 0.0000000001)

    alt = (r / math.cos(lat)) - (const_xkmper * c2)

    sgp_sun.lat = math.deg(lat)
    sgp_sun.lon = math.deg(lon)
    sgp_sun.alt = alt
    theta = thetaAux
    if sgp_sun.lon >= 180 then
        sgp_sun.lon = sgp_sun.lon - 360
    end
end


function SGP_calculateSunAzElev( jt )
    local i
    local sin_lat,cos_lat, sin_theta,cos_theta
    local el,azim,lat,theta
    local top_s,top_e,top_z

     --antiguamente llamado calcular variables

    local range = {}
    local rgvel = {}
    range.x = sgp_sun.x - sgp_location.x
    rgvel.x = 0.0 - sgp_location.vx
    range.y = sgp_sun.y - sgp_location.y
    rgvel.y = 0.0 - sgp_location.vy
    range.z = sgp_sun.z - sgp_location.z
    rgvel.z = 0.0 - sgp_location.vz

    range.m = SGP_magnitud(range.x,range.y,range.z)

    lat = sgp_location.polar.lat
    theta = sgp_location.polar.m
    sin_lat = math.sin(lat)
    cos_lat = math.cos(lat)
    sin_theta = math.sin(theta)
    cos_theta = math.cos(theta)
    top_s = sin_lat * cos_theta * range.x + sin_lat * sin_theta * range.y - cos_lat * range.z
    top_e = -sin_theta * range.x + cos_theta * range.y
    top_z = cos_lat * cos_theta * range.x + cos_lat * sin_theta * range.y + sin_lat * range.z
    azim = math.atan(-top_e/top_s) --Azimuth
    if (top_s > 0) then
        azim = azim + math.pi
    end
    if (azim < 0) then
        azim = azim + (math.pi * 2.0)
    end
    el = math.asin(top_z/range.m)
    sgp_sun.azi = math.deg(azim)  --Azimuth (radians to degrees)
    --sgp_sol.elevacion = el --Elevation (radians)
    sgp_sun.rango = range.m  --Range (kilometers)
    sgp_sun.ratioRango = SGP_dot(range,rgvel)/range.m --Range Rate (kilometers/second)
    -- Corrections for atmospheric refraction }
    -- Reference:  Astronomical Algorithms by Jean Meeus, pp. 101-104 }
    -- Note:  Correction is meaningless when apparent elevation is below horizon }
    sgp_sun.ele = el + math.rad((1.02/math.tan(math.rad(math.deg(el)+10.3/(math.deg(el)+5.11))))/60.0)
    --if (sgp_sun.ele < -3) then
    --  sgp_sun.ele = el  --reset to true elevation
    --end
    sgp_sun.ele = math.deg(sgp_sun.ele)
    sgp_location.noche = (sgp_sun.ele < const_twilightCivil)
end

function SGP_calculateSatAzElev (sat, jt)
    local i
    local sin_lat,cos_lat, sin_theta,cos_theta
    local el,azim,lat,theta
    local top_s,top_e,top_z

    SGP_calculateLocation(jt);

    local range = {}
    local rgvel = {}

    range.x = sat.x - sgp_location.x
    range.y = sat.y - sgp_location.y
    range.z = sat.z - sgp_location.z

    rgvel.x = sat.vx - sgp_location.vx
    rgvel.y = sat.vy - sgp_location.vy
    rgvel.z = sat.vz - sgp_location.vz

    range.m = SGP_magnitud(range.x,range.y,range.z)

    lat = sgp_location.polar.lat
    theta = sgp_location.polar.m
    sin_lat = math.sin(lat)
    cos_lat = math.cos(lat)
    sin_theta = math.sin(theta)
    cos_theta = math.cos(theta)
    top_s = sin_lat*cos_theta*range.x + sin_lat*sin_theta*range.y - cos_lat*range.z
    top_e = -sin_theta*range.x + cos_theta*range.y
    top_z = cos_lat*cos_theta*range.x + cos_lat*sin_theta*range.y + sin_lat*range.z
    azim = math.atan(-top_e/top_s) --Azimuth
    if (top_s > 0) then
        azim = azim + math.pi
    end
    if (azim < 0) then
        azim = azim + (math.pi*2.0)
    end
    el = math.asin(top_z/range.m)
    sat.azimut = math.deg(azim)  --Azimuth (radians to degrees)
    --sat.elevacion = el  --Elevation (radians)
    sat.rango = range.m  --Range (kilometers)
    sat.ratioRango = SGP_dot(range,rgvel)/range.m --Range Rate (kilometers/second)
    -- Corrections for atmospheric refraction }
    -- Reference:  Astronomical Algorithms by Jean Meeus, pp. 101-104 }
    -- Note:  Correction is meaningless when apparent elevation is below horizon }
    if not sat.primera_vez then
        sat.elevacion_ant = sat.elevacion
    else
        sat.primera_vez = false
    end

    sat.elevacion = el + math.rad((1.02/math.tan(math.rad(math.deg(el)+10.3/(math.deg(el)+5.11))))/60.0)
    if (sat.elevacion < 0) then
        sat.elevacion = el  --Reset to true elevation
    end
    sat.elevacion = math.deg(sat.elevacion)

end


function SGP_calculateSatVisibility(sat)
    sat.visible = ( (not sat.eclipsado) and (sgp_location.noche) and (sat.elevacion > 0))
end


function SGP_calculateLocation(jt)
    local c,s,achcp
    local lat, lon, alt, theta

    lat = sgp_location.polar.lat
    lon = sgp_location.polar.lon
    alt = sgp_location.polar.alt

    --LMST
    theta = SGP_modulus(SGP_thetaG_JD(jt) + lon,(math.pi * 2))
    sgp_location.polar.m=theta
    c = 1.0/math.sqrt(1.0 + const_f*(const_f - 2.0)*math.pow(math.sin(lat),2.0))
    s = ((1 - const_f)*(1 - const_f))*c
    achcp = (const_xkmper*c + alt)*math.cos(lat)
    sgp_location.x = achcp*math.cos(theta) -- kilometros
    sgp_location.y = achcp*math.sin(theta)
    sgp_location.z = (const_xkmper*s + alt)*math.sin(lat)
    sgp_location.vx = -const_mfactor*sgp_location.y --kilometers/second
    sgp_location.vy =  const_mfactor*sgp_location.x
    sgp_location.vz =  0

    sgp_location.m = SGP_magnitud(sgp_location.x,sgp_location.y,sgp_location.z)
    sgp_location.vm = SGP_magnitud(sgp_location.vx,sgp_location.vy,sgp_location.vz)
end

function SGP_calculateSatellite (s , jtime)
        SGP_calculateSatPosVel (sgp_sats[s], jtime)
        SGP_calculateSatIllum(sgp_sats[s])
        SGP_calculateSatLatLonAlt (sgp_sats[s], jtime)
        SGP_calculateSatAzElev (sgp_sats[s], jtime)
        SGP_calculateSatVisibility(sgp_sats[s])
end

function SGP_fixangle(a)
    return ((a) - 360.0 * (math.floor((a) / 360.0)))
end

--  KEPLER  --  Solve the equation of Kepler.

function SGP_kepler( m, ecc)

    local e, delta
    local EPSILON = 0.000001

    m = SGP_dtr(m)
    e = m
    repeat
        delta = e - ecc * math.sin(e) - m
        e = e - delta / (1 - ecc * math.cos(e))
    until not (math.abs(delta) > EPSILON)
    return e
end

function SGP_fixangr(a)
    return ((a) - (math.pi*2) * (math.floor((a) / (math.pi*2))))
end

function SGP_dtr(x)
    return ((x) * (math.pi / 180.0))
end

function SGP_rtd(x)
    return ((x) / (math.pi / 180.0))
end

function SGP_highmoon(jd)
    local t, t2, t3, t4, lprime, d, m, mprime, f, a1, a2, a3
    local e = {}
    local sigmaL, sigmaB, sigmaR, ang
    local i
    local l, b, r

    t = (jd - const_J2000) / const_JulianCentury

    t2 = t * t
    t3 = t * t2
    t4 = t * t3

    lprime = 218.3164591 + 481267.88134236 * t - 0.0013268 * t2 +
                t3 / 538841.0 - t4 / 65194000.0

    d = 297.8502042 + 445267.1115168 * t - 0.00163 * t2 +
                t3 / 545868.0 - t4 / 113065000.0

    m = 357.5291092 + 35999.0502909 * t - 0.0001536 * t2 +
                t3 / 24490000.0

    mprime = 134.9634114 + 477198.8676313 * t + 0.008997 * t2 +
                t3 / 69699.0 - t4 / 14712000.0

    f = 93.2720993 + 483202.0175273 * t - 0.0034029 * t2 -
                t3 / 3526000.0 + t4 / 863310000.0

    a1 = 119.75 + 131.849 * t

    a2 = 53.09 + 479264.29 * t

    a3 = 313.45 + 481266.484 * t

    e[1] = 1
    e[2] = 1 - (0.002516 * t) - (0.0000074 * t2)
    e[3] = e[2] * e[2]

    lprime = SGP_fixangr(SGP_dtr(lprime))
    d = SGP_fixangr(SGP_dtr(d))
    m = SGP_fixangr(SGP_dtr(m))
    mprime = SGP_fixangr(SGP_dtr(mprime))
    f = SGP_fixangr(SGP_dtr(f))
    a1 = SGP_fixangr(SGP_dtr(a1))
    a2 = SGP_fixangr(SGP_dtr(a2))
    a3 = SGP_fixangr(SGP_dtr(a3))

    sigmaR = 0
    sigmaB = 0
    sigmaL = 0

    for i = 1,const_NTERMS do
        ang = sgp_lrCoeff[i][1] * d + sgp_lrCoeff[i][2] * m +
              sgp_lrCoeff[i][3] * mprime + sgp_lrCoeff[i][4] * f
        sigmaL = sigmaL + sgp_lTerms[i] * math.sin(ang) * e[math.abs(sgp_lrCoeff[i][2])+1]
        if (sgp_rTerms[i] ~= 0) then
            sigmaR = sigmaR + sgp_rTerms[i] * math.cos(ang) * e[math.abs(sgp_lrCoeff[i][2])+1]
        end

        ang = sgp_bCoeff[i][1] * d + sgp_bCoeff[i][2] * m +
              sgp_bCoeff[i][3] * mprime + sgp_bCoeff[i][4] * f
        sigmaB = sigmaB + sgp_bTerms[i] * math.sin(ang) * e[math.abs(sgp_bCoeff[i][2])+1]
    end

    sigmaL = sigmaL + 3958.0 * math.sin(a1) + 1962.0 * math.sin(lprime - f) + 318.0 * math.sin(a2)

    sigmaB = sigmaB - 2235.0 * math.sin(lprime) + 382.0 * math.sin(a3) + 175.0 * math.sin(a1 - f) +
              175.0 * math.sin(a1 + f) + 127.0 * math.sin(lprime - mprime) - 115.0 * math.sin(lprime + mprime)

    l = SGP_rtd(lprime) + sigmaL / 1000000.0
    b = sigmaB / 1000000.0
    r = 385000.56 + sigmaR / 1000.0

    return l, b, r
end


function SGP_Asec(x)
    return ((x) / 3600.0)
end


--  OBLIQEQ  --  Calculate the obliquity of the ecliptic for a given Julian
         --date.  This uses Laskar's tenth-degree polynomial fit
         --(J. Laskar, Astronomy and Astrophysics, Vol. 157, page 68 [1986])
         --which is accurate to within 0.01 arc second between AD 1000
         --and AD 3000, and within a few seconds of arc for +/-10000
         --years around AD 2000.  If we're outside the range in which
         --this fit is valid (deep time) we simply return the J2000 value
        -- the obliquity, which happens to be almost precisely the mean.  */

function SGP_obliqeq( jd )

    local oterms = {SGP_Asec(-4680.93),
        SGP_Asec(   -1.55),
        SGP_Asec( 1999.25),
        SGP_Asec(  -51.38),
        SGP_Asec( -249.67),
        SGP_Asec(  -39.05),
        SGP_Asec(    7.12),
        SGP_Asec(   27.87),
        SGP_Asec(    5.79),
        SGP_Asec(    2.45)}


    local eps, i, u, v
    eps = 23 + (26 / 60.0) + (21.448 / 3600.0)
    u = (jd - const_J2000) / (const_JulianCentury * 100)
    v = u

    if (math.abs(u) < 1.0) then
        for i = 1, 10 do
            eps = eps + oterms[i] * v
            v = v * u
        end
    end
    return eps
end


--  ECLIPTOEQ  --  Convert celestial (ecliptical) longitude and latitude into
        --right ascension (in degrees) and declination.  We must supply
        --the time of the conversion in order to compensate correctly
        --for the varying obliquity of the ecliptic over time.  */

function SGP_ecliptoeq(jd,Lambda, Beta)
    local eps
    local Ra, Dec
    -- Obliquity of the ecliptic.

    eps = SGP_dtr(SGP_obliqeq(jd))

    Ra = SGP_fixangle(SGP_rtd(math.atan2((math.cos(eps) * math.sin(SGP_dtr(Lambda)) -
                         (math.tan(SGP_dtr(Beta)) * math.sin(eps))), math.cos(SGP_dtr(Lambda)))))
    Dec = SGP_rtd(math.asin((math.sin(eps) * math.sin(SGP_dtr(Lambda)) * math.cos(SGP_dtr(Beta))) +
                 (math.sin(SGP_dtr(Beta)) * math.cos(eps))))

    return Ra, Dec
end

function SGP_RADecToAzElev (jd, ra, dec, lat, lon)
    local r = math.rad(ra)
    local d = math.rad(dec)
    local n = math.rad(lat)    -- North latitude of tracking station
    local e = -math.rad(lon)   -- East longitude of tracking station

    -- Find siderial time in radians

    local t=(jd-2451545.0)/36525.0
    local teg=280.46061837+360.98564736629*(jd-2451545.0)+(0.000387933*t-t*t/38710000.0)*t

    while (teg>360.0) do
        teg = teg - 360.0
    end

    th = math.rad(teg - lon)
    while (th > 2*math.pi) do
        th = th - 2*math.pi
    end

    local h=th-r

    az=math.atan2(math.sin(h),math.cos(h)*math.sin(n)-math.tan(d)*math.cos(n))+math.pi
    el=math.asin(math.sin(n)*math.sin(d)+math.cos(n)*math.cos(d)*math.cos(h))

    local el_with_atmosphere_refraction = el + math.rad((1.02/math.tan(math.rad(math.deg(el)+10.3/(math.deg(el)+5.11))))/60.0)
    if (el_with_atmosphere_refraction < 0) then
        el_with_atmosphere_refraction = el  --reset to true elevation
    end

    return math.deg(az), math.deg(el_with_atmosphere_refraction)
end




--  GMST  --  Calculate Greenwich Mean Siderial Time for a given instant expressed as a Julian date and fraction.

function SGP_gmst(jd)
    local t, theta0

    -- Time, in Julian centuries of 36525 ephemeris days, measured from the epoch 1900 January 0.5 ET.
    t = ((math.floor(jd + 0.5) - 0.5) - 2415020.0) / const_JulianCentury
    theta0 = 6.6460656 + 2400.051262 * t + 0.00002581 * t * t
    t = (jd + 0.5) - (math.floor(jd + 0.5))
    theta0 = theta0 + (t * 24.0) * 1.002737908
    theta0 = (theta0 - 24.0 * (math.floor(theta0 / 24.0)))
    return theta0
end


function SGP_calculateMoon(jt)
    local Day, N, M, Ec, Lambdasun, ml, MM, MN, Ev, Ae, A3, MmP
    local mEc, A4, lP, Varia, lPP, NP, magnitud, z, y, x, Lambdamoon
    local MoonAge, MoonPhase, MoonDist, MoonDFrac, MoonAng
    local F, SunDist, SunAng

    -- Calculation of the Sun's position

    Day = jt - const_epoch                  --Date within epoch
    N = SGP_fixangle((360 / 365.2422) * Day)   -- Mean anomaly of the Sun
    M = SGP_fixangle(N + const_elonge - const_elongp)  --Convert from perigee co-ordinates to epoch 1980.0
    Ec = SGP_kepler(M, const_eccent)                    -- Solve equation of Kepler
    Ec = math.sqrt((1 + const_eccent) / (1 - const_eccent)) * math.tan(Ec / 2)
    Ec = 2 * SGP_rtd(math.atan(Ec))                 -- True anomaly
    Lambdasun = SGP_fixangle(Ec + const_elongp)     -- Sun's geocentric ecliptic longitude
    -- Orbital distance factor
    F = ((1 + const_eccent * math.cos(SGP_dtr(Ec))) / (1 - const_eccent * const_eccent))
    SunDist = const_SunSMAX / F                 -- Distance to Sun in km
    SunAng = F * const_sunangsiz                --Sun's angular size in degrees */

    -- Calculation of the Moon's position

    -- Moon's mean longitude
    ml = SGP_fixangle(13.1763966 * Day + const_mmlong)

    -- Moon's mean anomaly
    MM = SGP_fixangle(ml - 0.1114041 * Day - const_mmlongp)

    -- Moon's ascending node mean longitude
    MN = SGP_fixangle(const_mlnode - 0.0529539 * Day)

    -- Evection
    Ev = 1.2739 * math.sin(SGP_dtr(2 * (ml - Lambdasun) - MM))

    -- Annual equation
    Ae = 0.1858 * math.sin(SGP_dtr(M))

    -- Correction term
    A3 = 0.37 * math.sin(SGP_dtr(M))

    -- Corrected anomaly
    MmP = MM + Ev - Ae - A3

    -- Correction for the equation of the centre
    mEc = 6.2886 * math.sin(SGP_dtr(MmP))

    -- Another correction term
    A4 = 0.214 * math.sin(SGP_dtr(2 * MmP))

    -- Corrected longitude
    lP = ml + Ev + mEc - Ae + A4

    -- Variation
    Varia = 0.6583 * math.sin(SGP_dtr(2 * (lP - Lambdasun)))

    -- True longitude
    lPP = lP + Varia

    -- Corrected longitude of the node
    NP = MN - 0.16 * math.sin(SGP_dtr(M))

    -- Y inclination coordinate
    y = math.sin(SGP_dtr(lPP - NP)) * math.cos(SGP_dtr(const_minc))

    -- X inclination coordinate
    x = math.cos(SGP_dtr(lPP - NP))



    -- Ecliptic longitude
    Lambdamoon = SGP_rtd(math.atan2(y, x))
    Lambdamoon = Lambdamoon + NP

    -- Ecliptic latitude
    -- BetaM = rtd(asin(sin(dtr(lPP - NP)) * sin(dtr(minc))));

    -- Calculation of the phase of the Moon

    -- Age of the Moon in degrees
    MoonAge = lPP - Lambdasun

    -- Phase of the Moon
    MoonPhase = (1 - math.cos(SGP_dtr(MoonAge))) / 2

    -- Calculate distance of moon from the centre of the Earth

    MoonDist = (const_msmax * (1 - const_mecc * const_mecc)) / (1 + const_mecc * math.cos(SGP_dtr(MmP + mEc)))

    -- Calculate Moon's angular diameter

    MoonDFrac = MoonDist / const_msmax
    MoonAng = const_mangsiz / MoonDFrac

    -- Calculate Moon's parallax

    --    MoonPar = mparallax / MoonDFrac;

    SGP_calculateLocation(jt)

    local igmst = SGP_gmst(jt)

    local moonlong, moonlat, mooncrv = SGP_highmoon( jt )
    local moonra, moondec = SGP_ecliptoeq(jt, moonlong, moonlat)
    moonlong = (igmst * 15) - moonra;

    moonlong = -moonlong
    if (moonlong > 180) then
        moonlong = moonlong - 360
    elseif (moonlong < -180) then
        moonlong = moonlong + 360
    end

    local moonaz, moonele = SGP_RADecToAzElev(jt, moonra, moondec,sgp_location.lat, sgp_location.lon)

    sgp_moon.ra = moonra
    sgp_moon.dec = moondec
    sgp_moon.lon = moonlong
    sgp_moon.lat = moonlat
    sgp_moon.azi = moonaz
    sgp_moon.ele = moonele + (1.02/math.tan(math.rad(moonele+10.3/(moonele+5.11))))/60.0


    sgp_moon.phase = MoonPhase

    local aom = const_SynMonth * (SGP_fixangle(MoonAge) / 360.0)
    sgp_moon.age.cicle = aom / const_SynMonth
    sgp_moon.age.d = math.floor(aom)
    sgp_moon.age.h = math.floor(24 * (aom - math.floor(aom)))
    sgp_moon.age.m = math.floor((1440 * (aom - math.floor(aom))) % 60)
    sgp_moon.dist = MoonDist
    sgp_moon.ang = MoonAng
    sgp_moon.sun_dist = SunDist
    sgp_moon.sun_ang = SunAng

end




function SGP_calculateSunRaiseTime()
    SGP_getCurrentTime()
    local jtime = sgp_time.ujtime
    SGP_calculateSun (jtime)

    if sgp_sun.ele > 0 then
        repeat
            jtime = jtime - 0.000694446 * 10
            SGP_calculateSun (jtime)
        until (sgp_sun.ele < 0)
        repeat
            jtime = jtime + 0.000694446
            SGP_calculateSun (jtime)
        until (sgp_sun.ele > 0)
        repeat
            jtime = jtime - 0.000694446 * 0.16
            SGP_calculateSun (jtime)
        until (sgp_sun.ele <= 0)
    else
        repeat
            jtime = jtime + 0.000694446 * 10
            SGP_calculateSun (jtime)
        until (sgp_sun.ele > 0)
        repeat
            jtime = jtime - 0.000694446
            SGP_calculateSun (jtime)
        until (sgp_sun.ele < 0)
        repeat
            jtime = jtime + 0.000694446 * 0.16
            SGP_calculateSun (jtime)
        until (sgp_sun.ele >= 0)
    end

    SGP_calculateSun (sgp_time.ujtime)

    sgp_sun.raise.jt = SGP_UTC_to_Local(jtime)
    sgp_sun.raise.year , sgp_sun.raise.month, sgp_sun.raise.day, sgp_sun.raise.hour, sgp_sun.raise.min, sgp_sun.raise.sec = SGP_Julian_To_Date(sgp_sun.raise.jt)
end


function SGP_calculateMoonRaiseTime()
    SGP_getCurrentTime()
    local jtime = sgp_time.ujtime
    SGP_calculateMoon (jtime)

    if sgp_moon.ele > 0 then
        repeat
            jtime = jtime - 0.000694446 * 10
            SGP_calculateMoon (jtime)
        until (sgp_moon.ele < 0)
        repeat
            jtime = jtime + 0.000694446
            SGP_calculateMoon (jtime)
        until (sgp_moon.ele > 0)
        repeat
            jtime = jtime - 0.000694446 * 0.16
            SGP_calculateMoon (jtime)
        until (sgp_moon.ele <= 0)
    else
        repeat
            jtime = jtime + 0.000694446 * 10
            SGP_calculateMoon (jtime)
        until (sgp_moon.ele > 0)
        repeat
            jtime = jtime - 0.000694446
            SGP_calculateMoon (jtime)
        until (sgp_moon.ele < 0)
        repeat
            jtime = jtime + 0.000694446 * 0.16
            SGP_calculateMoon (jtime)
        until (sgp_moon.ele >= 0)
    end

    SGP_calculateMoon (sgp_time.ujtime)

    sgp_moon.raise.jt = SGP_UTC_to_Local(jtime)
    sgp_moon.raise.year , sgp_moon.raise.month, sgp_moon.raise.day, sgp_moon.raise.hour, sgp_moon.raise.min, sgp_moon.raise.sec = SGP_Julian_To_Date(sgp_moon.raise.jt)
end


function SGP_calculateSunSetTime()
    SGP_getCurrentTime()
    local jtime = sgp_time.ujtime
    SGP_calculateSun (jtime)

    if sgp_sun.ele < 0 then
        repeat
            jtime = jtime - 0.000694446 * 10
            SGP_calculateSun (jtime)
        until (sgp_sun.ele > 0)
        repeat
            jtime = jtime + 0.000694446
            SGP_calculateSun (jtime)
        until (sgp_sun.ele < 0)
        repeat
            jtime = jtime - 0.000694446 * 0.16
            SGP_calculateSun (jtime)
        until (sgp_sun.ele >= 0)
    else
        repeat
            jtime = jtime + 0.000694446 * 10
            SGP_calculateSun (jtime)
        until (sgp_sun.ele < 0)
        repeat
            jtime = jtime - 0.000694446
            SGP_calculateSun (jtime)
        until (sgp_sun.ele > 0)
        repeat
            jtime = jtime + 0.000694446 * 0.16
            SGP_calculateSun (jtime)
        until (sgp_sun.ele <= 0)
    end

    SGP_calculateSun (sgp_time.ujtime)

    sgp_sun.set.jt = SGP_UTC_to_Local(jtime)
    sgp_sun.set.year , sgp_sun.set.month, sgp_sun.set.day, sgp_sun.set.hour, sgp_sun.set.min, sgp_sun.set.sec = SGP_Julian_To_Date(sgp_sun.set.jt)
end

function SGP_calculateMoonSetTime()
    SGP_getCurrentTime()
    local jtime = sgp_time.ujtime
    SGP_calculateMoon (jtime)

    if sgp_moon.ele < 0 then
        repeat
            jtime = jtime - 0.000694446 * 10
            SGP_calculateMoon (jtime)
        until (sgp_moon.ele > 0)
        repeat
            jtime = jtime + 0.000694446
            SGP_calculateMoon (jtime)
        until (sgp_moon.ele < 0)
        repeat
            jtime = jtime - 0.000694446 * 0.16
            SGP_calculateMoon (jtime)
        until (sgp_moon.ele >= 0)
    else
        repeat
            jtime = jtime + 0.000694446 * 10
            SGP_calculateMoon (jtime)
        until (sgp_moon.ele < 0)
        repeat
            jtime = jtime - 0.000694446
            SGP_calculateMoon (jtime)
        until (sgp_moon.ele > 0)
        repeat
            jtime = jtime + 0.000694446 * 0.16
            SGP_calculateMoon (jtime)
        until (sgp_moon.ele <= 0)
    end

    SGP_calculateMoon (sgp_time.ujtime)

    sgp_moon.set.jt = SGP_UTC_to_Local(jtime)
    sgp_moon.set.year , sgp_moon.set.month, sgp_moon.set.day, sgp_moon.set.hour, sgp_moon.set.min, sgp_moon.set.sec = SGP_Julian_To_Date(sgp_moon.set.jt)
end


function SGP_calculateMoonPhases ()

    SGP_getCurrentTime();

    local day = sgp_time.day
    local mon = sgp_time.month
    local year = sgp_time.year

    local s
    local k, T, T2, T3, RAD, M, M1, F, AJ, BJ, CJ
    local JD



    for s=0,3 do
        k=math.floor((year+((mon+(day/30.0)-1.0)/12.0)-1900.0)*12.3685+0.5)
        k=k+0.25*s
        T=(k/1236.85)
        T2=T*T
        T3=T2*T
        RAD=57.29577951
        -- Tiempo para las fases medias
        JD=2415020.75933+29.53058868*k+0.0001178*T2-0.000000155*T3+0.00033*math.sin((166.56+132.87*T-0.009173*T2)/RAD)
        -- Anomalias mediasde Sol y Luna y arg. latitud
        M=359.2242+29.10535608*k-0.0000333*T2-0.00000347*T3
        M1=306.0253+385.81691806*k+0.0107306*T2+0.00001236*T3
        F=21.2964+390.67050646*k-0.0016528*T2-0.00000239*T3
        M=M/RAD
        M1=M1/RAD
        F=F/RAD
        -- Correción para Luna Nueva y Llena
        AJ=(0.1734-0.000393*T)*math.sin(M)+0.0021*math.sin(2*M)-0.4068*math.sin(M1)+0.0161*math.sin(2*M1)
        AJ=AJ-0.0004*math.sin(3*M1)+0.0104*math.sin(2*F)-0.0051*math.sin(M+M1)-0.0074*math.sin(M-M1)
        AJ=AJ+0.0004*math.sin(2*F+M)-0.0004*math.sin(2*F-M)-0.0006*math.sin(2*F+M1)+0.0010*math.sin(2*F-M1)
        AJ=AJ+0.0005*math.sin(M+2*M1)
        -- Correción para Cuarto creciente y menguante
        BJ=(0.1721-0.0004*T)*math.sin(M)+0.0021*math.sin(2*M)-0.6280*math.sin(M1)+0.0089*math.sin(2*M1)
        BJ=BJ-0.0004*math.sin(3*M1)+0.0079*math.sin(2*F)-0.0119*math.sin(M+M1)-0.0047*math.sin(M-M1)
        BJ=BJ+0.0003*math.sin(2*F+M)-0.0004*math.sin(2*F-M)-0.0006*math.sin(2*F+M1)+0.0021*math.sin(2*F-M1)
        BJ=BJ+0.0003*math.sin(M+2*M1)+0.0004*math.sin(M-2*M1)-0.0003*math.sin(2*M+M1)
        CJ=0.0028-0.0004*math.cos(M)+0.0003*math.cos(M1)
        if s==0 then
            sgp_moon.new_moon=JD+AJ
        end
        if s==1 then
            sgp_moon.first_quarter_moon=JD+BJ+CJ
        end
        if s==2 then
            sgp_moon.full_moon=JD+AJ
        end
        if s==3 then
            sgp_moon.third_quarter_moon=JD+BJ-CJ
        end

    end
end


function SGP_calculateNightEnding()
    SGP_getCurrentTime()
    local jtime = sgp_time.ujtime
    SGP_calculateSun (jtime)

    if sgp_sun.ele > const_twilightCivil then
        repeat
            jtime = jtime - 0.000694446 * 10
            SGP_calculateSun (jtime)
        until (sgp_sun.ele < const_twilightCivil)
        repeat
            jtime = jtime + 0.000694446
            SGP_calculateSun (jtime)
        until (sgp_sun.ele > const_twilightCivil)
        repeat
            jtime = jtime - 0.000694446 * 0.16
            SGP_calculateSun (jtime)
        until (sgp_sun.ele <= const_twilightCivil)
    else
        repeat
            jtime = jtime + 0.000694446 * 10
            SGP_calculateSun (jtime)
        until (sgp_sun.ele > const_twilightCivil)
        repeat
            jtime = jtime - 0.000694446
            SGP_calculateSun (jtime)
        until (sgp_sun.ele < const_twilightCivil)
        repeat
            jtime = jtime + 0.000694446 * 0.16
            SGP_calculateSun (jtime)
        until (sgp_sun.ele >= const_twilightCivil)
    end

    SGP_calculateSun (sgp_time.ujtime)

    sgp_location.day.jt = SGP_UTC_to_Local(jtime)
    sgp_location.day.year , sgp_location.day.month, sgp_location.day.day, sgp_location.day.hour, sgp_location.day.min, sgp_location.day.sec = SGP_Julian_To_Date(sgp_location.day.jt)
end


function SGP_calculateNightBegining()
    SGP_getCurrentTime()
    local jtime = sgp_time.ujtime
    SGP_calculateSun (jtime)

    if sgp_sun.ele < const_twilightCivil then
        repeat
            jtime = jtime - 0.000694446 * 10
            SGP_calculateSun (jtime)
        until (sgp_sun.ele > const_twilightCivil)
        repeat
            jtime = jtime + 0.000694446
            SGP_calculateSun (jtime)
        until (sgp_sun.ele < const_twilightCivil)
        repeat
            jtime = jtime - 0.000694446 * 0.16
            SGP_calculateSun (jtime)
        until (sgp_sun.ele >= const_twilightCivil)
    else
        repeat
            jtime = jtime + 0.000694446 * 10
            SGP_calculateSun (jtime)
        until (sgp_sun.ele < const_twilightCivil)
        repeat
            jtime = jtime - 0.000694446
            SGP_calculateSun (jtime)
        until (sgp_sun.ele > const_twilightCivil)
        repeat
            jtime = jtime + 0.000694446 * 0.16
            SGP_calculateSun (jtime)
        until (sgp_sun.ele <= const_twilightCivil)
    end

    SGP_calculateSun (sgp_time.ujtime)

    sgp_location.night.jt = SGP_UTC_to_Local(jtime)
    sgp_location.night.year , sgp_location.night.month, sgp_location.night.day, sgp_location.night.hour, sgp_location.night.min, sgp_location.night.sec = SGP_Julian_To_Date(sgp_location.night.jt)
end




-- COMIENZO DEL PROGRAMA - MAIN ()

SF_initialize()

-- Calculamos otras informaciones (fases lunares, amaneceres y ocasos...)
SF_clacularOtrosDatos()

sf_timer = timer.new()

while true do
    -- Obtenemos el tiempo actual
    SGP_getCurrentTime()

    -- Guardamos el valor anterior del tiempo
    if sf_primer_calculo then
        sf_current_jtime_ant = sgp_time.jtime
        sf_current_jtime = sgp_time.jtime
    else
        sf_current_jtime_ant = sf_current_jtime
        sf_current_jtime = sgp_time.jtime
    end

    -- Iniciamos el timer que mide el tiempo empleado en calculos
    sf_timer:start()

    --COMIENZA CALCULO

    -- Borramos el lienzo que se sacará a pantalla
    screen.clear(sf_sky.color)

    -- Dibujamos las lineas y texto de referencia
    SF_dibuarLineasReferencia()

    -- Dibujamos las constelacioens
    SF_procesarConstelaciones(sgp_time.ujtime)

    -- Dibujamos estrellas
    SF_procesarEstrellas(sgp_time.ujtime)

    -- Dibujamos el Sol
    SF_procesarSol(sgp_time.ujtime)

    -- Dibujamos la Luna
    SF_procesarLuna(sgp_time.ujtime)

    -- Dibujamos los satélites artificiales
    SF_procesarSatelites(sgp_time.ujtime)

    if sf_r_pressed and not sf_zoom_mode then
        SF_drawLocationInfo ()
        SF_drawTimeInfo ()
        SF_drawPSPInfo ()
    end
    -- Cogemos el tiempo invertido
    sf_milis_calculos = sf_timer:stop()
    sf_timer:reset()

    -- Guardamos fotogramas por segundo
    sf_fps = 1000.0 / sf_milis_calculos
    --screen.print(0, 0, string.format ("%.2f",sf_fps) .. " fps - "..string.format ("%.1f",sgp_mag_limit).." magnitud - sat ".. cursor_satelite.."  star ".. cursor_stars , sf_color_white)

    if not sf_r_pressed then
        SF_drawInfoBar(true)
    end

    -- Esperamos al refresco vertical
    screen.waitvblankstart()
    -- Pintar lienzo en pantalla
    screen.flip()

    -- Reproducir voces de aviso si hay que avisar de algo
    SND_playSoundsIfNeeded()

    -- Vemos si hay alguna tecla pulsada y actuamos en consecuencia
    SF_readInput()



    -- Si terminamos el primer calculo, establecer que ya no estamos en el primer calculo
    if sf_primer_calculo then
        -- Cambiamos a la paleta adecuada a las condiciones del cielo.
        if sgp_location.noche then
            sf_vision_nocturna = true
            SF_changePalette (sf_color_night.r,sf_color_night.g,sf_color_night.b)
        else
            sf_vision_nocturna = false
            SF_changePalette (sf_color_day.r,sf_color_day.g,sf_color_day.b)
        end
        sf_primer_calculo = false
    end

end