//Static methods
/////////////////////////////// Implementation ////////////////////////////////
public static double MeanGreenwichSiderealTime(double JD)
{
//Get the Julian day for the same day at midnight
int Year = 0;
int Month = 0;
int Day = 0;
int Hour = 0;
int Minute = 0;
double Second = 0;
CAADate date = new CAADate();
date.Set(JD, CAADate.AfterPapalReform(JD));
date.Get(ref Year, ref Month, ref Day, ref Hour, ref Minute, ref Second);
date.Set(Year, Month, Day, 0, 0, 0, date.InGregorianCalendar());
double JDMidnight = date.Julian();
//Calculate the sidereal time at midnight
double T = (JDMidnight - 2451545) / 36525;
double TSquared = T * T;
double TCubed = TSquared * T;
double Value = 100.46061837 + (36000.770053608 * T) + (0.000387933 * TSquared) - (TCubed / 38710000);
//Adjust by the time of day
Value += (((Hour * 15) + (Minute * 0.25) + (Second * 0.0041666666666666666666666666666667)) * 1.00273790935);
Value = CAACoordinateTransformation.DegreesToHours(Value);
return(CAACoordinateTransformation.MapTo0To24Range(Value));
}
public static CAA2DCoordinate Equatorial2Topocentric(double Alpha, double Delta, double Distance, double Longitude, double Latitude, double Height, double JD)
{
double RhoSinThetaPrime = CAAGlobe.RhoSinThetaPrime(Latitude, Height);
double RhoCosThetaPrime = CAAGlobe.RhoCosThetaPrime(Latitude, Height);
//Calculate the Sidereal time
double theta = CAASidereal.ApparentGreenwichSiderealTime(JD);
//Convert to radians
Delta = CAACoordinateTransformation.DegreesToRadians(Delta);
double cosDelta = Math.Cos(Delta);
//Calculate the Parallax
double pi = Math.Asin(GlobalMembersStdafx.g_AAParallax_C1 / Distance);
double sinpi = Math.Sin(pi);
//Calculate the hour angle
double H = CAACoordinateTransformation.HoursToRadians(theta - Longitude / 15 - Alpha);
double cosH = Math.Cos(H);
double sinH = Math.Sin(H);
//Calculate the adjustment in right ascension
double DeltaAlpha = Math.Atan2(-RhoCosThetaPrime * sinpi * sinH, cosDelta - RhoCosThetaPrime * sinpi * cosH);
CAA2DCoordinate Topocentric = new CAA2DCoordinate();
Topocentric.X = CAACoordinateTransformation.MapTo0To24Range(Alpha + CAACoordinateTransformation.RadiansToHours(DeltaAlpha));
Topocentric.Y = CAACoordinateTransformation.RadiansToDegrees(Math.Atan2((Math.Sin(Delta) - RhoSinThetaPrime * sinpi) * Math.Cos(DeltaAlpha), cosDelta - RhoCosThetaPrime * sinpi * cosH));
return(Topocentric);
}
public static double ApparentGreenwichSiderealTime(double JD)
{
double MeanObliquity = CAANutation.MeanObliquityOfEcliptic(JD);
double TrueObliquity = MeanObliquity + CAANutation.NutationInObliquity(JD) / 3600;
double NutationInLongitude = CAANutation.NutationInLongitude(JD);
double Value = MeanGreenwichSiderealTime(JD) + (NutationInLongitude * Math.Cos(CAACoordinateTransformation.DegreesToRadians(TrueObliquity)) / 54000);
return(CAACoordinateTransformation.MapTo0To24Range(Value));
}
//Static methods
public static CAANearParabolicObjectDetails Calculate(double JD, CAANearParabolicObjectElements elements)
{
double Epsilon = CAANutation.MeanObliquityOfEcliptic(elements.JDEquinox);
double JD0 = JD;
//What will be the return value
CAANearParabolicObjectDetails details = new CAANearParabolicObjectDetails();
Epsilon = CAACoordinateTransformation.DegreesToRadians(Epsilon);
double omega = CAACoordinateTransformation.DegreesToRadians(elements.omega);
double w = CAACoordinateTransformation.DegreesToRadians(elements.w);
double i = CAACoordinateTransformation.DegreesToRadians(elements.i);
double sinEpsilon = Math.Sin(Epsilon);
double cosEpsilon = Math.Cos(Epsilon);
double sinOmega = Math.Sin(omega);
double cosOmega = Math.Cos(omega);
double cosi = Math.Cos(i);
double sini = Math.Sin(i);
double F = cosOmega;
double G = sinOmega * cosEpsilon;
double H = sinOmega * sinEpsilon;
double P = -sinOmega * cosi;
double Q = cosOmega * cosi * cosEpsilon - sini * sinEpsilon;
double R = cosOmega * cosi * sinEpsilon + sini * cosEpsilon;
double a = Math.Sqrt(F * F + P * P);
double b = Math.Sqrt(G * G + Q * Q);
double c = Math.Sqrt(H * H + R * R);
double A = Math.Atan2(F, P);
double B = Math.Atan2(G, Q);
double C = Math.Atan2(H, R);
CAA3DCoordinate SunCoord = CAASun.EquatorialRectangularCoordinatesAnyEquinox(JD, elements.JDEquinox);
for (int j = 0; j < 2; j++)
{
double v = 0;
double r = 0;
CalulateTrueAnnomalyAndRadius(JD0, elements, ref v, ref r);
double x = r * a * Math.Sin(A + w + v);
double y = r * b * Math.Sin(B + w + v);
double z = r * c * Math.Sin(C + w + v);
if (j == 0)
{
details.HeliocentricRectangularEquatorial.X = x;
details.HeliocentricRectangularEquatorial.Y = y;
details.HeliocentricRectangularEquatorial.Z = z;
//Calculate the heliocentric ecliptic coordinates also
double u = omega + v;
double cosu = Math.Cos(u);
double sinu = Math.Sin(u);
details.HeliocentricRectangularEcliptical.X = r * (cosOmega * cosu - sinOmega * sinu * cosi);
details.HeliocentricRectangularEcliptical.Y = r * (sinOmega * cosu + cosOmega * sinu * cosi);
details.HeliocentricRectangularEcliptical.Z = r * sini * sinu;
details.HeliocentricEclipticLongitude = Math.Atan2(y, x);
details.HeliocentricEclipticLongitude = CAACoordinateTransformation.MapTo0To24Range(CAACoordinateTransformation.RadiansToDegrees(details.HeliocentricEclipticLongitude) / 15);
details.HeliocentricEclipticLatitude = Math.Asin(z / r);
details.HeliocentricEclipticLatitude = CAACoordinateTransformation.RadiansToDegrees(details.HeliocentricEclipticLatitude);
}
double psi = SunCoord.X + x;
double nu = SunCoord.Y + y;
double sigma = SunCoord.Z + z;
double Alpha = Math.Atan2(nu, psi);
Alpha = CAACoordinateTransformation.RadiansToDegrees(Alpha);
double Delta = Math.Atan2(sigma, Math.Sqrt(psi * psi + nu * nu));
Delta = CAACoordinateTransformation.RadiansToDegrees(Delta);
double Distance = Math.Sqrt(psi * psi + nu * nu + sigma * sigma);
if (j == 0)
{
details.TrueGeocentricRA = CAACoordinateTransformation.MapTo0To24Range(Alpha / 15);
details.TrueGeocentricDeclination = Delta;
details.TrueGeocentricDistance = Distance;
details.TrueGeocentricLightTime = CAAElliptical.DistanceToLightTime(Distance);
}
else
{
details.AstrometricGeocenticRA = CAACoordinateTransformation.MapTo0To24Range(Alpha / 15);
details.AstrometricGeocentricDeclination = Delta;
details.AstrometricGeocentricDistance = Distance;
details.AstrometricGeocentricLightTime = CAAElliptical.DistanceToLightTime(Distance);
double RES = Math.Sqrt(SunCoord.X * SunCoord.X + SunCoord.Y * SunCoord.Y + SunCoord.Z * SunCoord.Z);
details.Elongation = CAACoordinateTransformation.RadiansToDegrees(Math.Acos((RES * RES + Distance * Distance - r * r) / (2 * RES * Distance)));
details.PhaseAngle = CAACoordinateTransformation.RadiansToDegrees(Math.Acos((r * r + Distance * Distance - RES * RES) / (2 * r * Distance)));
}
if (j == 0) //Prepare for the next loop around
{
JD0 = JD - details.TrueGeocentricLightTime;
}
}
return(details);
}