public void get_InitStateJx(IAgOrbitStateClassical keplerState)
{
keplerState.SizeShapeType = AgEClassicalSizeShape.eSizeShapeSemimajorAxis;
IAgClassicalSizeShapeSemimajorAxis Orbitsize = keplerState.SizeShape as IAgClassicalSizeShapeSemimajorAxis;
keplerState.LocationType = AgEClassicalLocation.eLocationTrueAnomaly;
IAgClassicalLocationTrueAnomaly OrbitLocation = keplerState.Location as IAgClassicalLocationTrueAnomaly;
IAgClassicalOrientation OrbitOrientation = keplerState.Orientation as IAgClassicalOrientation;
OrbitOrientation.AscNodeType = AgEOrientationAscNode.eAscNodeRAAN;
IAgOrientationAscNodeRAAN OrbitAsc = keplerState.Orientation.AscNode as IAgOrientationAscNodeRAAN;
SemiMajorAxis = Orbitsize.SemiMajorAxis;
Eccentricity = Orbitsize.Eccentricity;
Inclination = OrbitOrientation.Inclination;
ArgOfPerigee = OrbitOrientation.ArgOfPerigee;
RAAN = OrbitAsc.Value;
TrueAnomaly = OrbitLocation.Value;
//Console.WriteLine(Orbitsize.SemiMajorAxis);
//IAgQuantity a = OrbitOrientation as IAgQuantity;
//Console.WriteLine(OrbitOrientation.Inclination);
}
// check if the resulting orbit is circular or parabolic/hyperbolic
private static bool IsCircular(IAgVePropagatorJ2Perturbation prop)
{
IAgOrbitStateClassical testOrbit = prop.InitialState.Representation.ConvertTo(AgEOrbitStateType.eOrbitStateClassical) as IAgOrbitStateClassical;
testOrbit.SizeShapeType = AgEClassicalSizeShape.eSizeShapeSemimajorAxis;
IAgClassicalSizeShapeSemimajorAxis testSizeShape = testOrbit.SizeShape as IAgClassicalSizeShapeSemimajorAxis;
if (testSizeShape.Eccentricity < 1.0)
{
return(true);
}
return(false);
}
private void CreateSat1TwoBody()
{
try
{
try
{ root.ExecuteCommand("Unload / */Satellite/Sat1"); }
catch
{ }
IAgSatellite sat1 = root.CurrentScenario.Children.New(AgESTKObjectType.eSatellite, "Sat1") as IAgSatellite;
sat1.SetPropagatorType(AgEVePropagatorType.ePropagatorTwoBody);
IAgVePropagatorTwoBody propSat1 = sat1.Propagator as IAgVePropagatorTwoBody;
propSat1.Step = 60;
IAgVeGfxAttributesOrbit sat1Graph = sat1.Graphics.Attributes as IAgVeGfxAttributesOrbit;
sat1Graph.Color = Color.LimeGreen;
sat1Graph.Line.Width = AgELineWidth.e2;
//'Definisco i parametri Kepleriani classici del satellite
IAgOrbitStateClassical classical2B = propSat1.InitialState.Representation.ConvertTo(AgEOrbitStateType.eOrbitStateClassical) as IAgOrbitStateClassical;
classical2B.CoordinateSystemType = AgECoordinateSystem.eCoordinateSystemJ2000;
//'Uso il semiasse maggiore e l'eccentricità per definire la forma e la dimensione dell'orbita
classical2B.SizeShapeType = AgEClassicalSizeShape.eSizeShapeSemimajorAxis;
IAgClassicalSizeShapeSemimajorAxis semi2B = classical2B.SizeShape as IAgClassicalSizeShapeSemimajorAxis;
semi2B.SemiMajorAxis = semimajorAxisSat1;
semi2B.Eccentricity = eccentricitySat1;
//'Per definire l'orientamento dell'orbita nello spazio uso l'inclinazione, l'argomento del perigeo e la RAAN
classical2B.Orientation.Inclination = inclinationSat1;
classical2B.Orientation.ArgOfPerigee = argOfPerigeeSat1;
classical2B.Orientation.AscNodeType = AgEOrientationAscNode.eAscNodeRAAN;
IAgOrientationAscNodeRAAN raan = classical2B.Orientation.AscNode as IAgOrientationAscNodeRAAN;
raan.Value = raanSat1;
//'uso l'anomalia vera per definire la posizione iniziale del satellite lungo la sua orbita
classical2B.LocationType = AgEClassicalLocation.eLocationTrueAnomaly;
IAgClassicalLocationTrueAnomaly trueAnomaly = classical2B.Location as IAgClassicalLocationTrueAnomaly;
trueAnomaly.Value = trueAnomSat1;
//'Infine assegno i parametri orbtali così definiti al satellite e lo propago
propSat1.InitialState.Representation.Assign(classical2B);
propSat1.Propagate();
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
// check if perigee radius is positive
private static bool IsPerigeePositive(IAgVePropagatorJ2Perturbation prop)
{
IAgOrbitStateClassical testOrbit = prop.InitialState.Representation.ConvertTo(AgEOrbitStateType.eOrbitStateClassical) as IAgOrbitStateClassical;
testOrbit.SizeShapeType = AgEClassicalSizeShape.eSizeShapeSemimajorAxis;
IAgClassicalSizeShapeSemimajorAxis testSizeShape = testOrbit.SizeShape as IAgClassicalSizeShapeSemimajorAxis;
// perigee radius = a(1-e)
double rPeri = testSizeShape.SemiMajorAxis * (1 - testSizeShape.Eccentricity);
if (rPeri > 3000.0)
{
return(true);
}
return(false);
}
private void CreateSat2J2()
{
try
{
try
{ root.ExecuteCommand("Unload / */Satellite/Sat2"); }
catch
{ }
IAgSatellite sat2 = root.CurrentScenario.Children.New(AgESTKObjectType.eSatellite, "Sat2") as IAgSatellite;
sat2.SetPropagatorType(AgEVePropagatorType.ePropagatorJ2Perturbation);
IAgVePropagatorJ2Perturbation propSat2 = sat2.Propagator as IAgVePropagatorJ2Perturbation;
propSat2.Step = 60;
IAgVeGfxAttributesOrbit sat2Graph = sat2.Graphics.Attributes as IAgVeGfxAttributesOrbit;
sat2Graph.Color = Color.Orange;
sat2Graph.Line.Width = AgELineWidth.e2;
IAgOrbitStateClassical classicalJ2 = propSat2.InitialState.Representation.ConvertTo(AgEOrbitStateType.eOrbitStateClassical) as IAgOrbitStateClassical;
classicalJ2.CoordinateSystemType = AgECoordinateSystem.eCoordinateSystemJ2000;
classicalJ2.SizeShapeType = AgEClassicalSizeShape.eSizeShapeSemimajorAxis;
IAgClassicalSizeShapeSemimajorAxis semiJ2 = classicalJ2.SizeShape as IAgClassicalSizeShapeSemimajorAxis;
semiJ2.SemiMajorAxis = semimajorAxisSat2;
semiJ2.Eccentricity = eccentricitySat2;
classicalJ2.Orientation.Inclination = inclinationSat2;
classicalJ2.Orientation.ArgOfPerigee = argOfPerigeeSat2;
classicalJ2.Orientation.AscNodeType = AgEOrientationAscNode.eAscNodeRAAN;
IAgOrientationAscNodeRAAN raan = classicalJ2.Orientation.AscNode as IAgOrientationAscNodeRAAN;
raan.Value = raanSat2;
classicalJ2.LocationType = AgEClassicalLocation.eLocationTrueAnomaly;
IAgClassicalLocationTrueAnomaly trueAnomaly = classicalJ2.Location as IAgClassicalLocationTrueAnomaly;
trueAnomaly.Value = trueAnomSat2;
propSat2.InitialState.Representation.Assign(classicalJ2);
propSat2.Propagate();
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
// check if apogee is above the Earth
private static bool IsApogeeAboveGround(IAgVePropagatorJ2Perturbation prop)
{
IAgOrbitStateClassical testOrbit = prop.InitialState.Representation.ConvertTo(AgEOrbitStateType.eOrbitStateClassical) as IAgOrbitStateClassical;
testOrbit.SizeShapeType = AgEClassicalSizeShape.eSizeShapeSemimajorAxis;
IAgClassicalSizeShapeSemimajorAxis testSizeShape = testOrbit.SizeShape as IAgClassicalSizeShapeSemimajorAxis;
// apogee radius = a(1+e)
double rApo = testSizeShape.SemiMajorAxis * (1 + testSizeShape.Eccentricity);
if (rApo > 6380.0)
{
return(true);
}
return(false);
}
public static bool UpdateClassicalOrbit(IAgSatellite sat, double a, double e, double i, double aop, double raan, double ta, ref string error)
{
IAgVePropagatorJ2Perturbation prop = sat.Propagator as IAgVePropagatorJ2Perturbation;
// need to set everything individually because true vs mean anomaly
IAgOrbitStateClassical keplerian = prop.InitialState.Representation.ConvertTo(AgEOrbitStateType.eOrbitStateClassical) as IAgOrbitStateClassical;
keplerian.SizeShapeType = AgEClassicalSizeShape.eSizeShapeSemimajorAxis;
IAgClassicalSizeShapeSemimajorAxis sizeShape = keplerian.SizeShape as IAgClassicalSizeShapeSemimajorAxis;
sizeShape.SemiMajorAxis = a;
sizeShape.Eccentricity = e;
keplerian.Orientation.Inclination = i;
keplerian.Orientation.ArgOfPerigee = aop;
(keplerian.Orientation.AscNode as IAgOrientationAscNodeRAAN).Value = raan;
keplerian.LocationType = AgEClassicalLocation.eLocationTrueAnomaly;
(keplerian.Location as IAgClassicalLocationTrueAnomaly).Value = ta;
prop.InitialState.Representation.Assign(keplerian);
return(Is_Error_Propagator(prop, ref error));
}
/* This code takes a set of Cartesian coordinates in a fixed frame and converts them into Keplerian orbital elements in an inertial frame
* without using a satellite object (using conversion utility within STK Engine). The Keplerian elements you would like to return can be specified
* by changing the enum values near the top of the Main function.
*/
static void Main(string[] args)
{
AgSTKXApplication app = new AgSTKXApplication();
app.NoGraphics = true;
AgStkObjectRoot root = new AgStkObjectRoot();
// Here are some preliminary variables for the classical coordinate elements you would like to obtain
SizeShapeTypes SizeShapeType = SizeShapeTypes.Altitude;
AscNodeTypes AscNodeType = AscNodeTypes.RAAN;
LocationTypes LocationType = LocationTypes.ArgumentOfLatitude;
// Here we create a new AgOrbitState object
IAgConversionUtility ConversionUtility = root.ConversionUtility;
IAgOrbitState cartesianOrbit = ConversionUtility.NewOrbitStateOnEarth();
// Here is how you display and change the epoch
Console.WriteLine("Epoch:");
cartesianOrbit.Epoch = "1 Jun 2003 17:00:00.000";
Console.WriteLine(cartesianOrbit.Epoch);
// Here we assign whatever Cartesian coordinates we would like to in a fixed frame
cartesianOrbit.AssignCartesian(AgECoordinateSystem.eCoordinateSystemFixed, 5598.42, -14988.6, 4.80738, 3.408, 1.27376, 2.60903);
// Now we convert the orbit to a classical orbit state
IAgOrbitStateClassical classicalOrbit = cartesianOrbit.ConvertTo(AgEOrbitStateType.eOrbitStateClassical) as IAgOrbitStateClassical;
Console.WriteLine(classicalOrbit.CoordinateSystemType);
// Prints out the first two classical orbit elements
switch (SizeShapeType)
{
case SizeShapeTypes.Altitude:
classicalOrbit.SizeShapeType = AgEClassicalSizeShape.eSizeShapeAltitude;
IAgClassicalSizeShapeAltitude sizeShapeAltitude = classicalOrbit.SizeShape as IAgClassicalSizeShapeAltitude;
Console.WriteLine("Apogee Altitude:");
Console.WriteLine(sizeShapeAltitude.ApogeeAltitude);
Console.WriteLine("Perigee Altitude:");
Console.WriteLine(sizeShapeAltitude.PerigeeAltitude);
break;
case SizeShapeTypes.MeanMotion:
classicalOrbit.SizeShapeType = AgEClassicalSizeShape.eSizeShapeMeanMotion;
IAgClassicalSizeShapeMeanMotion sizeShapeMeanMotion = classicalOrbit.SizeShape as IAgClassicalSizeShapeMeanMotion;
Console.WriteLine("Mean Motion:");
Console.WriteLine(sizeShapeMeanMotion.MeanMotion);
Console.WriteLine("Eccentricity:");
Console.WriteLine(sizeShapeMeanMotion.Eccentricity);
break;
case SizeShapeTypes.Period:
classicalOrbit.SizeShapeType = AgEClassicalSizeShape.eSizeShapePeriod;
IAgClassicalSizeShapePeriod sizeShapePeriod = classicalOrbit.SizeShape as IAgClassicalSizeShapePeriod;
Console.WriteLine("Period:");
Console.WriteLine(sizeShapePeriod.Period);
Console.WriteLine("Eccentricity:");
Console.WriteLine(sizeShapePeriod.Eccentricity);
break;
case SizeShapeTypes.Radius:
classicalOrbit.SizeShapeType = AgEClassicalSizeShape.eSizeShapeRadius;
IAgClassicalSizeShapeRadius sizeShapeRadius = classicalOrbit.SizeShape as IAgClassicalSizeShapeRadius;
Console.WriteLine("Apogee Radius:");
Console.WriteLine(sizeShapeRadius.ApogeeRadius);
Console.WriteLine("Perigee Radius:");
Console.WriteLine(sizeShapeRadius.PerigeeRadius);
break;
case SizeShapeTypes.SemimajorAxis:
classicalOrbit.SizeShapeType = AgEClassicalSizeShape.eSizeShapeSemimajorAxis;
IAgClassicalSizeShapeSemimajorAxis sizeShapeSemimajorAxis = classicalOrbit.SizeShape as IAgClassicalSizeShapeSemimajorAxis;
Console.WriteLine("Semimajor Axis:");
Console.WriteLine(sizeShapeSemimajorAxis.SemiMajorAxis);
Console.WriteLine("Eccentricity:");
Console.WriteLine(sizeShapeSemimajorAxis.Eccentricity);
break;
}
// Prints the inclination and argument of perigee
IAgClassicalOrientation orientation = classicalOrbit.Orientation;
Console.WriteLine("Inclination:");
Console.WriteLine(orientation.Inclination);
Console.WriteLine("Argument of Perigee:");
Console.WriteLine(orientation.ArgOfPerigee);
// This section prints the ascending node value
Console.WriteLine("Ascending Node:");
switch (AscNodeType)
{
case AscNodeTypes.RAAN:
orientation.AscNodeType = AgEOrientationAscNode.eAscNodeRAAN;
IAgOrientationAscNodeRAAN ascNodeRAAN = orientation.AscNode as IAgOrientationAscNodeRAAN;
Console.WriteLine(ascNodeRAAN.Value);
break;
case AscNodeTypes.LAN:
orientation.AscNodeType = AgEOrientationAscNode.eAscNodeLAN;
IAgOrientationAscNodeLAN ascNodeLAN = orientation.AscNode as IAgOrientationAscNodeLAN;
Console.WriteLine(ascNodeLAN.Value);
break;
}
// This section prints the location of the satellite along the orbit in terms of whatever you would like
Console.WriteLine("Location:");
switch (LocationType)
{
case LocationTypes.ArgumentOfLatitude:
classicalOrbit.LocationType = AgEClassicalLocation.eLocationArgumentOfLatitude;
IAgClassicalLocationArgumentOfLatitude locationArgumentOfLatitude = classicalOrbit.Location as IAgClassicalLocationArgumentOfLatitude;
Console.WriteLine(locationArgumentOfLatitude.Value);
break;
case LocationTypes.EccentricAnomaly:
classicalOrbit.LocationType = AgEClassicalLocation.eLocationEccentricAnomaly;
IAgClassicalLocationEccentricAnomaly locationSpecificEccentricAnomaly = classicalOrbit.Location as IAgClassicalLocationEccentricAnomaly;
Console.WriteLine(locationSpecificEccentricAnomaly.Value);
break;
case LocationTypes.MeanAnomaly:
classicalOrbit.LocationType = AgEClassicalLocation.eLocationMeanAnomaly;
IAgClassicalLocationMeanAnomaly locationSpecificMeanAnomaly = classicalOrbit.Location as IAgClassicalLocationMeanAnomaly;
Console.WriteLine(locationSpecificMeanAnomaly.Value);
break;
case LocationTypes.TimePastAN:
classicalOrbit.LocationType = AgEClassicalLocation.eLocationTimePastAN;
IAgClassicalLocationTimePastAN locationSpecificTimePastAN = classicalOrbit.Location as IAgClassicalLocationTimePastAN;
Console.WriteLine(locationSpecificTimePastAN.Value);
break;
case LocationTypes.TimePastPerigee:
classicalOrbit.LocationType = AgEClassicalLocation.eLocationTimePastPerigee;
IAgClassicalLocationTimePastPerigee locationSpecificTimePastPerigee = classicalOrbit.Location as IAgClassicalLocationTimePastPerigee;
Console.WriteLine(locationSpecificTimePastPerigee.Value);
break;
case LocationTypes.TrueAnomaly:
classicalOrbit.LocationType = AgEClassicalLocation.eLocationTrueAnomaly;
IAgClassicalLocationTrueAnomaly locationTrueAnomaly = classicalOrbit.Location as IAgClassicalLocationTrueAnomaly;
Console.WriteLine(locationTrueAnomaly.Value);
break;
}
Console.ReadLine();
}
