static void Main(string[] args)
{
// string line0 = "ISS (ZARYA) ";
string line1 = "1 25544U 98067A 20206.38292522 -.00000985 00000-0 -95291-5 0 9998";
string line2 = "2 25544 51.6430 164.3636 0001088 140.8410 323.1994 15.49511774237787";
Sat_Io io = new Sat_Io();
Satrec satrec = io.twoline2satrec(line1, line2);
Sgp4 sgp4 = new Sgp4();
PositionAndVelocity positionAndVelocity = sgp4.sgp4(satrec, 0);
// Set the Observer at 122.03 West by 36.96 North, in RADIANS
Geodetic observerGd = new Geodetic();
Transform tf = new Transform();
observerGd.longitude = tf.degreesToRadians(-122.0308);
observerGd.latitude = tf.degreesToRadians(36.9613422);
observerGd.height = 0.370;
Console.WriteLine(positionAndVelocity.position_ECI.x);
Console.WriteLine(positionAndVelocity.position_ECI.y);
Console.WriteLine(positionAndVelocity.position_ECI.z);
Console.WriteLine("Look i didnt crash");
}
public Geodetic eciToGeodetic(Coordiantes eci, double gmst)
{
// http://www.celestrak.com/columns/v02n03/
double a = 6378.137;
double b = 6356.7523142;
double R = Math.Sqrt((eci.x * eci.x) + (eci.y * eci.y));
double f = (a - b) / a;
double e2 = ((2 * f) - (f * f));
double longitude = Math.Atan2(eci.y, eci.x) - gmst;
while (longitude < -pi)
{
longitude += twoPi;
}
while (longitude > pi)
{
longitude -= twoPi;
}
double kmax = 20;
double k = 0;
double latitude = Math.Atan2(
eci.z,
Math.Sqrt((eci.x * eci.x) + (eci.y * eci.y))
);
double C = 0;
while (k < kmax)
{
C = 1 / Math.Sqrt(1 - (e2 * (Math.Sin(latitude) * Math.Sin(latitude))));
latitude = Math.Atan2(eci.z + (a * C * e2 * Math.Sin(latitude)), R);
k += 1;
}
double height = (R / Math.Cos(latitude)) - (a * C);
Geodetic geodetic = new Geodetic();
geodetic.longitude = longitude;
geodetic.latitude = latitude;
geodetic.height = height;
return(geodetic);
}
public Coordiantes geodeticToEcf(Geodetic geodetic)
{
double longitude = geodetic.longitude;
double latitude = geodetic.latitude;
double height = geodetic.height;
double a = 6378.137;
double b = 6356.7523142;
double f = (a - b) / a;
double e2 = ((2 * f) - (f * f));
double normal = a / Math.Sqrt(1 - (e2 * (Math.Sin(latitude) * Math.Sin(latitude))));
double x = (normal + height) * Math.Cos(latitude) * Math.Cos(longitude);
double y = (normal + height) * Math.Cos(latitude) * Math.Sin(longitude);
double z = ((normal * (1 - e2)) + height) * Math.Sin(latitude);
Coordiantes ecf = new Coordiantes();
ecf.x = x;
ecf.y = y;
ecf.z = z;
return(ecf);
}