// /////////////////////////////////////////////////////////////////////
static void Main(string[] args)
{
// Sample obsCodeode to test the SGP4 and SDP4 implementation. The test
// TLEs come from the NORAD document "Space Track Report No. 3".
// Test SGP4
string str1 = "SGP4 Test";
string str2 = "1 88888U 80275.98708465 .00073094 13844-3 66816-4 0 8";
string str3 = "2 88888 72.8435 115.9689 0086731 52.6988 110.5714 16.05824518 105";
TwoLineElement tle1 = new TwoLineElement(str1, str2, str3);
PrintPosVel(tle1);
Console.WriteLine();
// Test SDP4
str1 = "SDP4 Test";
str2 = "1 11801U 80230.29629788 .01431103 00000-0 14311-1 8";
str3 = "2 11801 46.7916 230.4354 7318036 47.4722 10.4117 2.28537848 6";
TwoLineElement tle2 = new TwoLineElement(str1, str2, str3);
PrintPosVel(tle2);
Console.WriteLine("\nExample output:");
// Example: Define a location on the earth, then determine the look-angle
// to the SDP4 satellite defined above.
// Create an orbit object using the SDP4 TLE object.
// Satellite satSDP4 = new Satellite(tle2);
Orbit orbit = new Orbit(tle2);
// Get the location of the satellite from the Orbit object. The
// earth-centered inertial information is placed into eciSDP4.
// Here we ask for the location of the satellite 90 minutes after
// the TLE epoch.
TimedMotionState eciSDP4 = orbit.PositionEci(90.0);
// Now create a site object. Site objects represent a location on the
// surface of the earth. Here we arbitrarily select a point on the
// equator.
GeoCoord siteEquator = new GeoCoord(0.0, -100.0, 0); // 0.00 N, 100.00 W, 0 km altitude
// Now get the "look angle" from the site to the satellite.
// Note that the ECI object "eciSDP4" has a time associated
// with the coordinates it contains; this is the time at which
// the look angle is valid.
TopoCoord topoLook = OrbitUtils.GetSatTopoCoord(eciSDP4, siteEquator);
// Print out the results. Note that the Azimuth and Elevation are
// stored in the CoordTopo object as radians. Here we funcKeyToDouble
// to degrees using Rad2Deg()
Console.Write("AZ: {0:f3} EL: {1:f3}\n",
topoLook.Azimuth,
topoLook.Elevation);
}
/// <summary>
/// Calculate satellite ECI position/velocity for a given time.
/// </summary>
/// <param name="mpe">Target time, in minutes past the TLE epoch.</param>
/// <returns>Kilometer-based position/velocity ECI coordinates.</returns>
public TimedMotionState PositionEci(double mpe)
{
TimedMotionState eci = NoradModel.GetPosition(mpe);
// Convert ECI vector units from AU to kilometers
double radiusAe = OrbitConsts.RadiusOfEquator / OrbitConsts.Ae;
eci.ScalePosVector(radiusAe); // km
eci.ScaleVelVector(radiusAe * (OrbitConsts.MinPerDay / 86400.0)); // km/sec
return eci;
}
private void button_solve_Click(object sender, EventArgs e)
{
TwoLineElement tle = GetTwoLineElement();
Gnsser.Orbits.Orbit orbit = new Gnsser.Orbits.Orbit(tle);
double intervalMin = Double.Parse(this.textBox_intervalMin.Text);
double count = Int32.Parse(this.textBox_count.Text);
List <TimedMotionState> sateStates = new List <TimedMotionState>();
for (int i = 0; i < count; i++)
{
double time = i * intervalMin;
TimedMotionState eciSDP4 = orbit.PositionEci(time);
sateStates.Add(eciSDP4);
}
if (sateStates.Count == 0)
{
return;
}
StringBuilder sb = new StringBuilder();
sb.AppendLine(orbit.ToString());
sb.AppendLine(tle.ToString());
foreach (var item in sateStates)
{
sb.AppendLine(item.ToString());
}
this.textBox_show.Text = sb.ToString();
int j = 0;
lonlats = new List <AnyInfo.Geometries.Point>();
foreach (var item in sateStates)
{
GeoCoord geoCoord = CoordTransformer.XyzToGeoCoord(item.Position * 1000, AngleUnit.Degree);
lonlats.Add(new AnyInfo.Geometries.Point(geoCoord, j + "", item.Date.ToTime().ToString("hh:mm:ss")));
j++;
}
}
private void button_radarCaculate_Click(object sender, EventArgs e)
{
bool isGeoCoord = this.radioButton_geoCoord.Checked;
GeoCoord siteCoord = null;
if (isGeoCoord)
{
siteCoord = GeoCoord.Parse(this.textBox_coord.Text);
siteCoord.Unit = AngleUnit.Degree;
}
else
{
XYZ xyz = XYZ.Parse(this.textBox_coord.Text);
siteCoord = CoordTransformer.XyzToGeoCoord(xyz);
}
TwoLineElement tle = GetTwoLineElement();
Gnsser.Orbits.Orbit orbit = new Gnsser.Orbits.Orbit(tle);
double intervalMin = Double.Parse(this.textBox_intervalMin.Text);
double count = Int32.Parse(this.textBox_count.Text);
lonlats = new List <AnyInfo.Geometries.Point>();
lonlats.Add(new AnyInfo.Geometries.Point(siteCoord, "SitePoint"));
for (int i = 0; i < count; i++)
{
double time = i * intervalMin;
TimedMotionState eciSDP4 = orbit.PositionEci(time);
TopoCoord topoLook = OrbitUtils.GetSatTopoCoord(eciSDP4, siteCoord);
if (topoLook.Elevation > 0)
{
GeoCoord geoCoord = CoordTransformer.XyzToGeoCoord(eciSDP4.Position * 1000, AngleUnit.Degree);
lonlats.Add(new AnyInfo.Geometries.Point(geoCoord, i + ""));
}
}
}
/// <summary>
/// 根据卫星位置和测站位置计算其在站星坐标系中的位置。
/// Returns the topo-centric (azimuth, elevation, etc.) coordinates for
/// a target object described by the given ECI coordinates.
/// </summary>
/// <param name="satPos">The ECI coordinates of the target object.</param>
/// <param name="siteCoord">The ECI coordinates of the 观测站</param>
/// <returns>The look angle to the target object.</returns>
public static TopoCoord GetSatTopoCoord(TimedMotionState satPos, GeoCoord siteCoord)
{
// Calculate the ECI coordinates for this Site object at the time of interest.
Julian date = satPos.Date;
MotionState sitePos = OrbitUtils.GetMovingState(siteCoord, date);
XYZ vecV = satPos.Velocity - sitePos.Velocity;
XYZ vecP = satPos.Position - sitePos.Position;
// The site's Local Mean Sidereal Time at the time of interest.
double thetaRad = date.GetLocalMeanSiderealTime(siteCoord.Lon, false);
double sinLat = Math.Sin(siteCoord.Lat);
double cosLat = Math.Cos(siteCoord.Lat);
double sinTheta = Math.Sin(thetaRad);
double cosTheta = Math.Cos(thetaRad);
double top_s = sinLat * cosTheta * vecP.X +
sinLat * sinTheta * vecP.Y -
cosLat * vecP.Z;
double top_e = -sinTheta * vecP.X +
cosTheta * vecP.Y;
double top_z = cosLat * cosTheta * vecP.X +
cosLat * sinTheta * vecP.Y +
sinLat * vecP.Z;
double az = Math.Atan(-top_e / top_s);
if (top_s > 0.0)
{
az += OrbitConsts.PI;
}
if (az < 0.0)
{
az += 2.0 * OrbitConsts.PI;
}
double el = Math.Asin(top_z / vecP.Radius());
double rate = vecP.Dot(vecV) / vecP.Radius();
TopoCoord topo = new TopoCoord(
az, // azimuth, radians
el, // elevation, radians
vecP.Radius(), // range
rate // rate, per sec
);
#if WANT_ATMOSPHERIC_CORRECTION
// Elevation correction for atmospheric refraction.
// Reference: Astronomical Algorithms by Jean Meeus, pp. 101-104
// Note: Correction is meaningless when apparent elevation is below horizon
topo.Elevation += AngularConvert.DegToRad((1.02 /
Math.Tan(AngularConvert.DegToRad(AngularConvert.RadToDeg(el) + 10.3 /
(AngularConvert.RadToDeg(el) + 5.11)))) / 60.0);
if (topo.Elevation < 0.0)
{
topo.Elevation = el; // Reset to true elevation
}
if (topo.Elevation > (Consts.PI / 2.0))
{
topo.Elevation = (Consts.PI / 2.0);
}
#endif
return(topo);
}
