public static CAAEllipticalObjectDetails Calculate(double JD, CAAEllipticalObjectElements elements) { var Epsilon = CAANutation.MeanObliquityOfEcliptic(elements.JDEquinox); var JD0 = JD; //What will be the return value var details = new CAAEllipticalObjectDetails(); Epsilon = CAACoordinateTransformation.DegreesToRadians(Epsilon); var omega = CAACoordinateTransformation.DegreesToRadians(elements.omega); var w = CAACoordinateTransformation.DegreesToRadians(elements.w); var i = CAACoordinateTransformation.DegreesToRadians(elements.i); var sinEpsilon = Math.Sin(Epsilon); var cosEpsilon = Math.Cos(Epsilon); var sinOmega = Math.Sin(omega); var cosOmega = Math.Cos(omega); var cosi = Math.Cos(i); var sini = Math.Sin(i); var F = cosOmega; var G = sinOmega * cosEpsilon; var H = sinOmega * sinEpsilon; var P = -sinOmega * cosi; var Q = cosOmega *cosi *cosEpsilon - sini *sinEpsilon; var R = cosOmega *cosi *sinEpsilon + sini *cosEpsilon; var a = Math.Sqrt(F *F + P *P); var b = Math.Sqrt(G *G + Q *Q); var c = Math.Sqrt(H *H + R *R); var A = Math.Atan2(F, P); var B = Math.Atan2(G, Q); var C = Math.Atan2(H, R); var n = MeanMotionFromSemiMajorAxis(elements.a); var SunCoord = CAASun.EquatorialRectangularCoordinatesAnyEquinox(JD, elements.JDEquinox); for (var j =0; j<2; j++) { var M = n * (JD0 - elements.T); var E = CAAKepler.Calculate(M, elements.e); E = CAACoordinateTransformation.DegreesToRadians(E); var v = 2 *Math.Atan(Math.Sqrt((1 + elements.e) / (1 - elements.e)) * Math.Tan(E/2)); var r = elements.a * (1 - elements.e *Math.Cos(E)); var x = r * a * Math.Sin(A + w + v); var y = r * b * Math.Sin(B + w + v); var 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 var u = omega + v; var cosu = Math.Cos(u); var 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); } var psi = SunCoord.X + x; var nu = SunCoord.Y + y; var sigma = SunCoord.Z + z; var Alpha = Math.Atan2(nu, psi); Alpha = CAACoordinateTransformation.RadiansToDegrees(Alpha); var Delta = Math.Atan2(sigma, Math.Sqrt(psi *psi + nu *nu)); Delta = CAACoordinateTransformation.RadiansToDegrees(Delta); var 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 = DistanceToLightTime(Distance); } else { details.AstrometricGeocenticRA = CAACoordinateTransformation.MapTo0To24Range(Alpha / 15); details.AstrometricGeocentricDeclination = Delta; details.AstrometricGeocentricDistance = Distance; details.AstrometricGeocentricLightTime = DistanceToLightTime(Distance); var RES = Math.Sqrt(SunCoord.X *SunCoord.X + SunCoord.Y *SunCoord.Y + SunCoord.Z *SunCoord.Z); details.Elongation = Math.Acos((RES *RES + Distance *Distance - r *r) / (2 * RES * Distance)); details.Elongation = CAACoordinateTransformation.RadiansToDegrees(details.Elongation); details.PhaseAngle = Math.Acos((r *r + Distance *Distance - RES *RES) / (2 * r * Distance)); details.PhaseAngle = CAACoordinateTransformation.RadiansToDegrees(details.PhaseAngle); } if (j == 0) //Prepare for the next loop around JD0 = JD - details.TrueGeocentricLightTime; } return details; }
public static CAAEllipticalObjectDetails Calculate(double JD, CAAEllipticalObjectElements elements) { double Epsilon = CAANutation.MeanObliquityOfEcliptic(elements.JDEquinox); double JD0 = JD; //What will be the return value CAAEllipticalObjectDetails details = new CAAEllipticalObjectDetails(); 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); double n = CAAElliptical.MeanMotionFromSemiMajorAxis(elements.a); CAA3DCoordinate SunCoord = CAASun.EquatorialRectangularCoordinatesAnyEquinox(JD, elements.JDEquinox); for (int j = 0; j < 2; j++) { double M = n * (JD0 - elements.T); double E = CAAKepler.Calculate(M, elements.e); E = CAACoordinateTransformation.DegreesToRadians(E); double v = 2 * Math.Atan(Math.Sqrt((1 + elements.e) / (1 - elements.e)) * Math.Tan(E / 2)); double r = elements.a * (1 - elements.e * Math.Cos(E)); 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 = DistanceToLightTime(Distance); } else { details.AstrometricGeocenticRA = CAACoordinateTransformation.MapTo0To24Range(Alpha / 15); details.AstrometricGeocentricDeclination = Delta; details.AstrometricGeocentricDistance = Distance; details.AstrometricGeocentricLightTime = DistanceToLightTime(Distance); double RES = Math.Sqrt(SunCoord.X * SunCoord.X + SunCoord.Y * SunCoord.Y + SunCoord.Z * SunCoord.Z); details.Elongation = Math.Acos((RES * RES + Distance * Distance - r * r) / (2 * RES * Distance)); details.Elongation = CAACoordinateTransformation.RadiansToDegrees(details.Elongation); details.PhaseAngle = Math.Acos((r * r + Distance * Distance - RES * RES) / (2 * r * Distance)); details.PhaseAngle = CAACoordinateTransformation.RadiansToDegrees(details.PhaseAngle); } if (j == 0) //Prepare for the next loop around { JD0 = JD - details.TrueGeocentricLightTime; } } return(details); }