/// <summary>
/// 构造函数(注意单位的一致性)
/// </summary>
/// <param name="t0">初始时刻(s),没有多大意义</param>
/// <param name="elements">初始轨道根数</param>
/// <param name="j2UnnormalizedValue">J2项系数</param>
/// <param name="referenceDistance">参考椭球体半长轴</param>
public J2NumericalPropagator(double t0, KeplerianElements elements, double j2UnnormalizedValue, double referenceDistance)
: this(elements.GravitationalParameter, j2UnnormalizedValue, referenceDistance)
{
this.T0 = t0;
// 初始位置、速度
InitialCondition = elements.ToCartesian();
}
/// <summary>
/// Propagate a Platform using a NumericalPropagator configured with the entered KeplerianElements,
/// ForceModels, NumericalIntegrator, and start and stop dates.
/// </summary>
private void PropagateSatellite()
{
KeplerianElements orbitalElements = m_keplerianOrbitalElementsEntry.KeplerianElementValues;
if (orbitalElements == null)
{
return;
}
Motion <Cartesian> initialMotion = orbitalElements.ToCartesian();
PropagationNewtonianPoint point = new PropagationNewtonianPoint(m_elementID, m_forceModelSettings.CurrentCentralBody.InertialFrame, initialMotion.Value, initialMotion.FirstDerivative);
point.Mass = new ScalarFixed(double.Parse(m_mass.Text));
m_forceModelSettings.SetForceModelsOnPoint(point, new ScalarFixed(double.Parse(m_area.Text)));
CentralBody primaryCentralBody = m_forceModelSettings.CurrentCentralBody;
NumericalPropagatorDefinition state = new NumericalPropagatorDefinition();
state.IntegrationElements.Add(point);
state.Integrator = m_integratorSettings.GetIntegrator();
JulianDate start = new JulianDate(GregorianDate.ParseExact(m_start.Text, DateFormat, null));
JulianDate end = new JulianDate(GregorianDate.ParseExact(m_end.Text, DateFormat, null));
state.Epoch = start;
NumericalPropagator propagator = state.CreatePropagator();
propagator.StepTaken += (sender, args) =>
{
// Telling the propagator to stop if we get too close to the central body
Cartesian position = propagator.Converter.ConvertState <Cartesian>(m_elementID, args.CurrentState).Value;
if (position.Magnitude <= primaryCentralBody.Shape.SemimajorAxisLength + 10000)
{
args.Indication = PropagationEventIndication.StopPropagationAfterStep;
}
};
DateMotionCollection <Cartesian> answer = null;
var backgroundCalculation = new BackgroundCalculation();
backgroundCalculation.DoWork += (sender, e) =>
{
// actually propagate
var result = propagator.Propagate(end.Subtract(start), 1, backgroundCalculation);
answer = result.GetDateMotionCollection <Cartesian>(m_elementID);
};
backgroundCalculation.ProgressChanged += (sender, e) => m_propagationProgress.Value = e.ProgressPercentage;
backgroundCalculation.RunWorkerCompleted += (sender, e) =>
{
// when finished, draw the satellite
DrawSatellite(answer, primaryCentralBody.InertialFrame);
m_propagate.Enabled = true;
};
m_propagate.Enabled = false;
backgroundCalculation.RunWorkerAsync();
}
public static void TestLamber1()
{
double Gm = 3.986e14;
double sma = 7000000;
double ecc = 0.09956;
double f1 = 0.0;
double f2 = Math.PI;
//double f2 = 1.0;
//double f2 = 5.0;
KeplerianElements k1 = new KeplerianElements(sma, ecc, 0.2, 0.4, 1.0, f1, Gm);
KeplerianElements k2 = new KeplerianElements(sma, ecc, 0.2, 0.4, 1.0, f2, Gm);
double tof = KeplerianElements.ComputeTimeOfFlight(f1, f2, sma, ecc, Gm);
Motion <Cartesian> rv1 = k1.ToCartesian();
Motion <Cartesian> rv2 = k2.ToCartesian();
Cartesian v1p, v2p;
Lambert_RhGooding(Gm, rv1.Value, rv1.FirstDerivative, rv2.Value, rv2.FirstDerivative, tof, out v1p, out v2p);
Cartesian dv1 = v1p - rv1.FirstDerivative;
Cartesian dv2 = v2p - rv2.FirstDerivative;
}
