/// <summary>
/// J2积分器(惯性系中计算，无岁差章动)，右函数采用J2Gravity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 PropagatorDefinitionPureJ2(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)，无岁差章动
J2Gravity gravity = new J2Gravity(position.IntegrationPoint, centralBody, gravitationalParameter, j2UnnormalizedValue, referenceDistance);
// 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>
/// Gets the integrator as configured.
/// </summary>
public NumericalIntegrator GetIntegrator()
{
if (m_integrator.SelectedItem.ToString() == RKF78)
{
RungeKuttaFehlberg78Integrator integrator = new RungeKuttaFehlberg78Integrator
{
Direction = IntegrationSense.Increasing,
InitialStepSize = double.Parse(m_stepSize.Text),
MaximumStepSize = double.Parse(m_maxStep.Text),
MinimumStepSize = double.Parse(m_minStep.Text),
AbsoluteTolerance = double.Parse(m_maxError.Text)
};
if (m_fixedOrRelative.SelectedItem.ToString() == RELATIVE)
{
integrator.StepSizeBehavior = KindOfStepSize.Relative;
}
else if (m_fixedOrRelative.SelectedItem.ToString() == FIXED)
{
integrator.StepSizeBehavior = KindOfStepSize.Fixed;
}
return(integrator);
}
if (m_integrator.SelectedItem.ToString() == RK4)
{
return(new RungeKutta4Integrator
{
InitialStepSize = double.Parse(m_stepSize.Text)
});
}
throw new InvalidOperationException("Unknown integrator");
}
/// <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;
}
