/// <summary>
/// 通过运动状态初始化。
/// </summary>
/// <param name="MotionState">空间直角坐标系中的坐标和速度向量</param>
public CelestialMomentEllipseOrbit(MotionState MotionState)
{
#region 由运动状态计算轨道6根数
var pos = MotionState.Position;
var velocity = MotionState.Velocity;
//中间变量准备
XYZ hXyz = pos.Cross(velocity);
double hLen = hXyz.Length;
double r = pos.Length;
double vv = velocity.Dot(velocity);
//计算轨道倾角
double i = Math.Acos(hXyz.Z / hLen); //表示在Z轴上的投影，与上结果计算一致
//计算升交点赤经
double Ω = Math.Atan2(hXyz.X, -hXyz.Y);
//计算轨道长半轴a，
double a = 1 / (2 / r - vv / GeoConst.GM); //由活力公式计算
double sqrtA = Math.Sqrt(a);
double n = Math.Sqrt(GeoConst.GM) / (sqrtA * sqrtA * sqrtA); //平运动角速度n
//离心率e,偏近点角E ,平近点交M
double rdotv = pos.Dot(velocity);
double eCosE = 1 - r / a;
double eSinE = rdotv / Math.Sqrt(GeoConst.GM * a);
double e = Math.Sqrt(eSinE * eSinE + eCosE * eCosE); //离心率e
double E = Math.Atan2(eSinE, eCosE); //偏近点角E
double M = E - eSinE; //平近点角
//计算近升角距ω
XYZ eXyz = velocity.Cross(hXyz) / GeoConst.GM - pos.UnitVector();
double ω = Math.Atan2(eXyz.Z, (eXyz.Y * Math.Sin(Ω) + eXyz.X * Math.Cos(Ω)) * Math.Sin(i));
double u = Math.Atan2(pos.Z, (pos.Y * Math.Sin(Ω) + pos.X * Math.Cos(Ω)) * Math.Sin(i));
double ff = u - ω;//真近点角
#endregion
var momentEllipseOrbit = new MomentEllipseOrbit(M, new PlaneEllipse(a, e));
Init(ω, i, Ω, momentEllipseOrbit);
}
/// <summary>
/// 通过参数初始化
/// </summary>
/// <param name="argumentOfPerigee">近地点弧角ω</param>
/// <param name="inclination">轨道倾角</param>
/// <param name="rightAscensionOfAscendingNode">升交点赤经</param>
/// <param name="MomentEllipseOrbit">时刻平面轨道</param>
private void Init(double argumentOfPerigee, double inclination, double rightAscensionOfAscendingNode, MomentEllipseOrbit MomentEllipseOrbit)
{
this.ArgumentOfPerigee = argumentOfPerigee;
this.RightAscensionOfAscendingNode = rightAscensionOfAscendingNode;
this.Inclination = inclination;
this.MomentEllipseOrbit = MomentEllipseOrbit;
}
/// <summary>
/// 通过参数初始化
/// </summary>
/// <param name="argumentOfPerigee">近地点弧角ω</param>
/// <param name="inclination">轨道倾角</param>
/// <param name="rightAscensionOfAscendingNode">升交点赤经</param>
/// <param name="MomentEllipseOrbit">时刻平面轨道</param>
public CelestialMomentEllipseOrbit(double argumentOfPerigee, double inclination, double rightAscensionOfAscendingNode, MomentEllipseOrbit MomentEllipseOrbit)
{
Init(argumentOfPerigee, inclination, rightAscensionOfAscendingNode, MomentEllipseOrbit);
}
