// Edit By: Li Yunfei
// 20161208: 初次编写
// 20170104: 使用Orbitbase中的常数
/// <summary>
/// 中心天体J2项摄动力(含中心引力，惯性系中计算，含岁差章动)，右函数采用SphericalHarmonicGravity模型
/// <para>**缺省单位:m,m/s</para>
/// <para>**Mu,J2,Re默认采用缺省值</para>
/// </summary>
/// <param name="position">PropagationNewtonianPoint,单位:m,m/s</param>
/// <param name="centralBody"></param>
/// <param name="gravitationalParameter">引力常数GM(m^3/s^2)</param>
/// <param name="j2UnnormalizedValue">J2</param>
/// <param name="referenceDistance">Re(m)</param>
public static SphericalHarmonicGravity GetJ2Gravity(PropagationNewtonianPoint position, CentralBody centralBody, double gravitationalParameter = OrbitBase.EarthMu, double j2UnnormalizedValue = OrbitBase.EarthJ2, double referenceDistance = OrbitBase.EarthRe)
{
// 中心天体的J2项引力摄动(含中心引力，中心天体的惯性系中计算)，含岁差章动
SphericalHarmonicGravity gravity = new SphericalHarmonicGravity();
gravity.TargetPoint = position.IntegrationPoint; //* Will represent the position during propagation
// 单位一致性检查
if (gravitationalParameter > 1e10 && (referenceDistance < 1e6 || position.InitialPosition.Magnitude < 1e6))
{
throw new Exception("单位不一致Gm/Re/position!");
}
if (gravitationalParameter < 1e10 && (referenceDistance > 1e6 || position.InitialPosition.Magnitude > 1e6))
{
throw new Exception("单位不一致Gm/Re/position!");
}
double[][] coe = new double[3][];
coe[0] = new double[1];
coe[1] = new double[2];
coe[2] = new double[3];
SphericalHarmonicGravityModel gravityModel = new SphericalHarmonicGravityModel("WGS84", centralBody.Name, gravitationalParameter, referenceDistance, new double[] { 1.0, 0.0, j2UnnormalizedValue }, coe, coe, false, false);
int degree = 2;
int order = 0;
bool includeTwoBodyForce = true;
gravity.GravityField = new SphericalHarmonicGravityField(gravityModel, degree, order, includeTwoBodyForce, SphericalHarmonicsTideType.None);
return(gravity);
}
/// <summary>
/// J2积分器(惯性系中计算，含岁差章动)，右函数采用SphericalHarmonicGravity模型
/// <para>积分变量仅位置、速度</para>
/// <para>给position仅添加J2项右函数</para>
/// <para>RKF7(8)数值积分器，缺省绝对和相对精度皆为1e-13</para>
/// <para>Epoch属性需手动赋值</para>
/// </summary>
/// <param name="position">PropagationNewtonianPoint,单位:m,m/s</param>
/// <param name="centralBody"></param>
/// <param name="gravitationalParameter">引力常数GM(m^3/s^2)</param>
/// <param name="j2UnnormalizedValue">J2</param>
/// <param name="referenceDistance">Re(m)</param>
/// <param name="absTolerance">RKF7(8)的绝对精度</param>
/// <param name="relRolerance">RKF7(8)的相对精度</param>
public PropagatorDefinitionJ2(PropagationNewtonianPoint position, CentralBody centralBody, double gravitationalParameter = 3.986004418e14, double j2UnnormalizedValue = 0.001082629989052, double referenceDistance = 6378137.0, double absTolerance = 1e-13, double relRolerance = 1e-13)
{
// 中心天体的J2项引力摄动(含中心引力，中心天体的惯性系中计算)，含岁差章动
SphericalHarmonicGravity gravity = new SphericalHarmonicGravity();
gravity.TargetPoint = position.IntegrationPoint; //* Will represent the position during propagation
double[][] coe = new double[3][];
coe[0] = new double[1];
coe[1] = new double[2];
coe[2] = new double[3];
SphericalHarmonicGravityModel gravityModel = new SphericalHarmonicGravityModel("WGS84", centralBody.Name, gravitationalParameter, referenceDistance, new double[] { 1.0, 0.0, j2UnnormalizedValue }, coe, coe, false, false);
int degree = 2;
int order = 0;
bool includeTwoBodyForce = true;
gravity.GravityField = new SphericalHarmonicGravityField(gravityModel, degree, order, includeTwoBodyForce, SphericalHarmonicsTideType.None);
// 添加右函数
position.AppliedForces.Clear();
position.AppliedForces.Add(gravity);
// 积分变量
this.IntegrationElements.Add(position);
// RKF7(8)数值积分器
RungeKuttaFehlberg78Integrator integrator = new RungeKuttaFehlberg78Integrator();
integrator.AbsoluteTolerance = absTolerance;
integrator.RelativeTolerance = relRolerance;
integrator.InitialStepSize = 60.0;
integrator.StepSizeBehavior = KindOfStepSize.Relative;
integrator.MaximumStepSize = 200.0;
integrator.MinimumStepSize = 1.0;
//* This is STK's default and truncates each step to 3 decimal places
integrator.StepTruncationOrder = -3;
this.Integrator = integrator;
}
/// <summary>
/// This will configure the entered point with all of the force models as entered in the GUI.
/// </summary>
/// <param name="point">The point to add the force models too.</param>
/// <param name="area">The Scalar representing the area that the SRP and Drag model will see.</param>
public void SetForceModelsOnPoint(PropagationNewtonianPoint point, Scalar area)
{
point.AppliedForces.Clear();
if (m_useSRP.Checked)
{
SimpleSolarRadiationForce srp = new SimpleSolarRadiationForce(point.IntegrationPoint, double.Parse(m_reflectivity.Text), area);
if (m_shadowModel.SelectedItem.ToString() == DUALCONE)
{
srp.OccultationFactor = new ScalarOccultationDualCone(CentralBodiesFacet.GetFromContext().Sun,
point.IntegrationPoint);
}
else if (m_shadowModel.SelectedItem.ToString() == CYLINDRICAL)
{
srp.OccultationFactor = new ScalarOccultationCylindrical(CentralBodiesFacet.GetFromContext().Sun,
point.IntegrationPoint);
}
foreach (string id in m_eclipsingBodies.CheckedItems)
{
srp.OccultationFactor.OccludingBodies.Add(CentralBodiesFacet.GetFromContext().GetByName(id));
}
point.AppliedForces.Add(srp);
}
if (m_useDrag.Checked)
{
ScalarAtmosphericDensity density = null;
SolarGeophysicalData geoData = new ConstantSolarGeophysicalData(double.Parse(m_averageSolarFlux.Text),
double.Parse(m_solarFlux.Text),
double.Parse(m_kp.Text));
if (m_densityModel.SelectedItem.ToString() == JR)
{
density = new ScalarDensityJacchiaRoberts(point.IntegrationPoint, geoData);
}
else if (m_densityModel.SelectedItem.ToString() == MSIS86)
{
density = new ScalarDensityMsis86(point.IntegrationPoint, geoData);
}
else if (m_densityModel.SelectedItem.ToString() == MSIS90)
{
density = new ScalarDensityMsis90(point.IntegrationPoint, geoData);
}
else if (m_densityModel.SelectedItem.ToString() == MSIS2000)
{
density = new ScalarDensityMsis2000(point.IntegrationPoint, geoData);
}
AtmosphericDragForce atmo = new AtmosphericDragForce(density, new ScalarFixed(double.Parse(m_dragCoeff.Text)), area);
point.AppliedForces.Add(atmo);
}
ThirdBodyGravity thirdGravity = new ThirdBodyGravity(point.IntegrationPoint);
foreach (string item in m_thirdBodies.CheckedItems)
{
if (item == EARTH || item == SUN || item == MOON)
{
thirdGravity.AddThirdBody(item, CentralBodiesFacet.GetFromContext().GetByName(item).CenterOfMassPoint, m_gravConstants[item]);
}
else
{
thirdGravity.AddThirdBody(item, m_jplInfo.GetCenterOfMassPoint(m_nameToJplMapping[item]), m_gravConstants[item]);
}
}
thirdGravity.CentralBody = CentralBodiesFacet.GetFromContext().GetByName(m_primaryCB.SelectedItem.ToString());
if (thirdGravity.ThirdBodies.Count > 0)
{
point.AppliedForces.Add(thirdGravity);
}
// Primary gravity
string primaryCB = m_primaryCB.SelectedItem.ToString();
if (m_twoBody.Checked)
{
TwoBodyGravity gravity = new TwoBodyGravity(point.IntegrationPoint, CentralBodiesFacet.GetFromContext().GetByName(primaryCB), m_gravConstants[primaryCB]);
point.AppliedForces.Add(gravity);
}
else
{
SphericalHarmonicsTideType tideType = SphericalHarmonicsTideType.None;
if (m_tides.SelectedItem.ToString() == NOTIDES)
{
tideType = SphericalHarmonicsTideType.None;
}
else if (m_tides.SelectedItem.ToString() == PERMANENTTIDES)
{
tideType = SphericalHarmonicsTideType.PermanentTideOnly;
}
int order = int.Parse(m_order.Text);
int degree = int.Parse(m_degree.Text);
SphericalHarmonicGravityModel model = SphericalHarmonicGravityModel.ReadFrom(m_gravFile.Text);
SphericalHarmonicGravity gravity = new SphericalHarmonicGravity(point.IntegrationPoint,
new SphericalHarmonicGravityField(model, degree, order, true, tideType));
point.AppliedForces.Add(gravity);
if (gravity.GravityField.CentralBody.Name != primaryCB)
{
throw new InvalidDataException("The central body you have selected does not match the central body in the gravity file.");
}
}
if (primaryCB == EARTH)
{
point.IntegrationFrame = CentralBodiesFacet.GetFromContext().Earth.InternationalCelestialReferenceFrame;
}
else if (primaryCB == MOON)
{
point.IntegrationFrame = CentralBodiesFacet.GetFromContext().Moon.InertialFrame;
}
}
