/// <summary>
/// Get Position of the Earth
/// </summary>
/// <param name="T"></param>
/// <returns></returns>
private static Xyz GetPosExp0(double T)
{
double lambda = 279.0358 + 360.00769 * T + (1.9159 - 0.00005 * T) * UdMath.udsin((356.531) + (359.991) * T);
for (int i = 0; i < SunLambda.GetLength(0); i++)
{
lambda += SunLambda[i].a * UdMath.udsin(SunLambda[i].b + SunLambda[i].c * T);
}
lambda += 0.0057;
lambda = UdMath.deg2rad(UdMath.degmal(lambda));
double beta = 0.0;
double q = (-0.007261 + 0.0000002 * T) * UdMath.udcos((356.53) + (359.991) * T) + 0.000030;
for (int i = 0; i < SunQ.GetLength(0); i++)
{
q += SunQ[i].a * UdMath.udcos(SunQ[i].b + SunQ[i].b * T);
}
double radius = Math.Pow(10.0, q);
return(new Xyz(-radius * Math.Cos(beta) * Math.Cos(lambda),
-radius * Math.Cos(beta) * Math.Sin(lambda),
-radius * Math.Sin(beta)));
}
/// <summary>
/// Orbital element to Xyz
/// </summary>
/// <returns></returns>
public Xyz GetPos()
{
double re = this.e * 180.0 / Math.PI;
double E, M, oldE;
E = M = this.L - (this.w + this.N);
do
{
oldE = E;
E = M + re * UdMath.udsin(oldE);
} while (Math.Abs(E - oldE) > 1.0e-5 * 180.0 / Math.PI);
double px = this.a * (UdMath.udcos(E) - this.e);
double py = this.a * Math.Sqrt(1.0 - this.e * this.e) * UdMath.udsin(E);
double sinperi = UdMath.udsin(this.w);
double cosperi = UdMath.udcos(this.w);
double sinnode = UdMath.udsin(this.N);
double cosnode = UdMath.udcos(this.N);
double sinincl = UdMath.udsin(this.i);
double cosincl = UdMath.udcos(this.i);
double xc = px * (cosnode * cosperi - sinnode * cosincl * sinperi)
- py * (cosnode * sinperi + sinnode * cosincl * cosperi);
double yc = px * (sinnode * cosperi + cosnode * cosincl * sinperi)
- py * (sinnode * sinperi - cosnode * cosincl * cosperi);
double zc = px * (sinincl * sinperi)
+ py * (sinincl * cosperi);
return(new Xyz(xc, yc, zc));
}
/// <summary>
/// Mean orbital element of Jupiter with perturbation
/// </summary>
/// <param name="jd"></param>
private void PerturbationJupiter(double jd)
{
int year = (int)((jd - 1721423.5) / 365.244 + 1.0);
double T = year / 1000.0;
double L7 = (0.42 - 0.075 * T + 0.015 * T * T - 0.003 * T * T * T) * UdMath.udsin((T - 0.62) * 360.0 / 0.925);
double PS7 = 0.02 * UdMath.udsin((T + 0.1) * 360.0 / 0.925);
double PH7 = 0.03 * UdMath.udsin((T + 0.36) * 360.0 / 0.925);
double ETA = UdMath.degmal(86.1 + 0.033459 * (jd - 1721057.0));
double ZETA = UdMath.degmal(89.1 + 0.049630 * (jd - 1721057.0));
double L8 = PerturbationElement(ETA, ZETA, perturbJup1) / 1000.0;
double PS8 = PerturbationElement(ETA, ZETA, perturbJup2) / 1000.0;
double PH8 = PerturbationElement(ETA, ZETA, perturbJup3) / 1000.0;
double PH = 2.58 + 0.1 * T;
if (PH > 3.5)
{
PH = 3.5;
}
if (PH < 1.5)
{
PH = 1.5;
}
L += (L7 + L8);
w += (PS7 + PS8) / UdMath.udsin(PH);
e = UdMath.udsin(PH + PH7 + PH8);
}
/// <summary>
/// Mean orbital element of Saturn with perturbation
/// </summary>
/// <param name="jd"></param>
void PerturbationSaturn(double jd)
{
int year = (int)((jd - 1721423.5) / 365.244 + 1.0);
double T = year / 1000.0;
double AT = 0.88 - 0.0633 * T + 0.03 * T * T - 0.0006 * T * T * T;
double L7 = -0.50 + AT * UdMath.udsin((T - 0.145) * 360.0 / 0.95);
double PS7 = -0.50 + (0.10 - 0.005 * T) * UdMath.udsin((T - 0.54) * 360.0 / 0.95);
double PH7 = -0.50 + (0.10 - 0.005 * T) * UdMath.udsin((T - 0.32) * 360.0 / 0.95);
double AX7 = -0.050 + (0.004 - 0.0005 * T) * UdMath.udsin((T - 0.35) * 360.0 / 0.95);
double ETA = UdMath.degmal(86.1 + 0.033459 * (jd - 1721057.0));
double ZETA = UdMath.degmal(89.1 + 0.049630 * (jd - 1721057.0));
double L8 = PerturbationElement(ETA, ZETA, perturbSat1) / 100.0;
double PS8 = PerturbationElement(ETA, ZETA, perturbSat2) / 100.0;
double PH8 = PerturbationElement(ETA, ZETA, perturbSat3) / 100.0;
double AX8 = PerturbationElement(ETA, ZETA, perturbSat4) / 1000.0;
double PH = 3.56 - 0.175 * T - 0.005 * T * T;
/* if year > 7000 then PH < 2.0 */
if (PH < 2.0)
{
PH = 2.0;
}
L += (L7 + L8);
w += (PS7 + PS8) / UdMath.udsin(PH);
e = UdMath.udsin(PH + PH7 + PH8);
a += AX7 + AX8;
}
private void DoGetPlanetOrbit(PlanetElm planetElm)
{
double ae2 = -2.0 * planetElm.a * planetElm.e;
double t = Math.Sqrt(1.0 - planetElm.e * planetElm.e);
int xp1 = 0;
int xp2 = (this.Division / 2);
int xp3 = (this.Division / 2);
int xp4 = this.Division;
double E = 0.0;
for (int i = 0; i <= (this.Division / 4); i++, E += (360.0 / this.Division))
{
double rcosv = planetElm.a * (UdMath.udcos(E) - planetElm.e);
double rsinv = planetElm.a * t * UdMath.udsin(E);
this.Orbit[xp1++] = new Xyz(rcosv, rsinv, 0.0);
this.Orbit[xp2--] = new Xyz(ae2 - rcosv, rsinv, 0.0);
this.Orbit[xp3++] = new Xyz(ae2 - rcosv, -rsinv, 0.0);
this.Orbit[xp4--] = new Xyz(rcosv, -rsinv, 0.0);
}
}
