public static COR 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 = CT.D2R(Delta); double cosDelta = Math.Cos(Delta); //Calculate the Parallax double pi = Math.Asin(GFX.g_AAParallax_C1 / Distance); double sinpi = Math.Sin(pi); //Calculate the hour angle double H = CT.H2R(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); COR Topocentric = new COR(); Topocentric.X = CT.M24(Alpha + CT.R2H(DeltaAlpha)); Topocentric.Y = CT.R2D(Math.Atan2((Math.Sin(Delta) - RhoSinThetaPrime * sinpi) * Math.Cos(DeltaAlpha), cosDelta - RhoCosThetaPrime * sinpi * cosH)); return(Topocentric); }
//Conversion functions public static COR Equatorial2TopocentricDelta(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 = CT.D2R(Delta); double cosDelta = Math.Cos(Delta); //Calculate the Parallax double pi = Math.Asin(GFX.g_AAParallax_C1 / Distance); //Calculate the hour angle double H = CT.H2R(theta - Longitude / 15 - Alpha); double cosH = Math.Cos(H); double sinH = Math.Sin(H); COR DeltaTopocentric = new COR(); DeltaTopocentric.X = CT.R2H(-pi * RhoCosThetaPrime * sinH / cosDelta); DeltaTopocentric.Y = CT.R2D(-pi * (RhoSinThetaPrime * cosDelta - RhoCosThetaPrime * cosH * Math.Sin(Delta))); return(DeltaTopocentric); }
//Static methods ////////////////////// Implementation ///////////////////////////////////////// public static double ParallacticAngle(double HourAngle, double Latitude, double delta) { HourAngle = CT.H2R(HourAngle); Latitude = CT.D2R(Latitude); delta = CT.D2R(delta); return(CT.R2D(Math.Atan2(Math.Sin(HourAngle), Math.Tan(Latitude) * Math.Cos(delta) - Math.Sin(delta) * Math.Cos(HourAngle)))); }
public static double NutationInDeclination(double Alpha, double Delta, double Obliquity, double NutationInLongitude, double NutationInObliquity) { //Convert to radians Alpha = CT.H2R(Alpha); Delta = CT.D2R(Delta); Obliquity = CT.D2R(Obliquity); return(Math.Sin(Obliquity) * Math.Cos(Alpha) * NutationInLongitude + Math.Sin(Alpha) * NutationInObliquity); }
public static double NutationInRightAscension(double Alpha, double Delta, double Obliquity, double NutationInLongitude, double NutationInObliquity) { //Convert to radians Alpha = CT.H2R(Alpha); Delta = CT.D2R(Delta); Obliquity = CT.D2R(Obliquity); return((Math.Cos(Obliquity) + Math.Sin(Obliquity) * Math.Sin(Alpha) * Math.Tan(Delta)) * NutationInLongitude - Math.Cos(Alpha) * Math.Tan(Delta) * NutationInObliquity); }
public static double EclipticLongitudeOnHorizon(double LocalSiderealTime, double ObliquityOfEcliptic, double Latitude) { LocalSiderealTime = CT.H2R(LocalSiderealTime); Latitude = CT.D2R(Latitude); ObliquityOfEcliptic = CT.D2R(ObliquityOfEcliptic); double @value = CT.R2D(Math.Atan2(-Math.Cos(LocalSiderealTime), Math.Sin(ObliquityOfEcliptic) * Math.Tan(Latitude) + Math.Cos(ObliquityOfEcliptic) * Math.Sin(LocalSiderealTime))); return(CT.M360(@value)); }
public static double AngleBetweenEclipticAndHorizon(double LocalSiderealTime, double ObliquityOfEcliptic, double Latitude) { LocalSiderealTime = CT.H2R(LocalSiderealTime); Latitude = CT.D2R(Latitude); ObliquityOfEcliptic = CT.D2R(ObliquityOfEcliptic); double @value = CT.R2D(Math.Acos(Math.Cos(ObliquityOfEcliptic) * Math.Sin(Latitude) - Math.Sin(ObliquityOfEcliptic) * Math.Cos(Latitude) * Math.Sin(LocalSiderealTime))); return(CT.M360(@value)); }
public static double PositionAngle(double Alpha0, double Delta0, double Alpha, double Delta) { //Convert to radians Alpha0 = CT.H2R(Alpha0); Alpha = CT.H2R(Alpha); Delta0 = CT.D2R(Delta0); Delta = CT.D2R(Delta); return(CT.M360(CT.R2D(Math.Atan2(Math.Cos(Delta0) * Math.Sin(Alpha0 - Alpha), Math.Sin(Delta0) * Math.Cos(Delta) - Math.Cos(Delta0) * Math.Sin(Delta) * Math.Cos(Alpha0 - Alpha))))); }
public static double TopocentricMoonSemidiameter(double DistanceDelta, double Delta, double H, double Latitude, double Height) { //Convert to radians H = CT.H2R(H); Delta = CT.D2R(Delta); double pi = Math.Asin(6378.14 / DistanceDelta); double A = Math.Cos(Delta) * Math.Sin(H); double B = Math.Cos(Delta) * Math.Cos(H) - CAAGlobe.RhoCosThetaPrime(Latitude, Height) * Math.Sin(pi); double C = Math.Sin(Delta) - CAAGlobe.RhoSinThetaPrime(Latitude, Height) * Math.Sin(pi); double q = Math.Sqrt(A * A + B * B + C * C); double s = CT.D2R(GeocentricMoonSemidiameter(DistanceDelta) / 3600); return(CT.R2D(Math.Asin(Math.Sin(s) / q)) * 3600); }
public static COR EquatorialPMToEcliptic(double Alpha, double Delta, double Beta, double PMAlpha, double PMDelta, double Epsilon) { //Convert to radians Epsilon = CT.D2R(Epsilon); Alpha = CT.H2R(Alpha); Delta = CT.D2R(Delta); Beta = CT.D2R(Beta); double cosb = Math.Cos(Beta); double sinEpsilon = Math.Sin(Epsilon); COR @value = new COR(); @value.X = (PMDelta * sinEpsilon * Math.Cos(Alpha) + PMAlpha * Math.Cos(Delta) * (Math.Cos(Epsilon) * Math.Cos(Delta) + sinEpsilon * Math.Sin(Delta) * Math.Sin(Alpha))) / (cosb * cosb); @value.Y = (PMDelta * (Math.Cos(Epsilon) * Math.Cos(Delta) + sinEpsilon * Math.Sin(Delta) * Math.Sin(Alpha)) - PMAlpha * sinEpsilon * Math.Cos(Alpha) * Math.Cos(Delta)) / cosb; return(@value); }
public static CAATopocentricEclipticDetails Ecliptic2Topocentric(double Lambda, double Beta, double Semidiameter, double Distance, double Epsilon, double Longitude, double Latitude, double Height, double JD) { double S = CAAGlobe.RhoSinThetaPrime(Latitude, Height); double C = CAAGlobe.RhoCosThetaPrime(Latitude, Height); //Convert to radians Lambda = CT.D2R(Lambda); Beta = CT.D2R(Beta); Epsilon = CT.D2R(Epsilon); Longitude = CT.D2R(Longitude); Latitude = CT.D2R(Latitude); Semidiameter = CT.D2R(Semidiameter); double sine = Math.Sin(Epsilon); double cose = Math.Cos(Epsilon); double cosBeta = Math.Cos(Beta); double sinBeta = Math.Sin(Beta); //Calculate the Sidereal time double theta = CAASidereal.ApparentGreenwichSiderealTime(JD); theta = CT.H2R(theta); double sintheta = Math.Sin(theta); //Calculate the Parallax double pi = Math.Asin(GFX.g_AAParallax_C1 / Distance); double sinpi = Math.Sin(pi); double N = Math.Cos(Lambda) * cosBeta - C * sinpi * Math.Cos(theta); CAATopocentricEclipticDetails Topocentric = new CAATopocentricEclipticDetails(); Topocentric.Lambda = Math.Atan2(Math.Sin(Lambda) * cosBeta - sinpi * (S * sine + C * cose * sintheta), N); double cosTopocentricLambda = Math.Cos(Topocentric.Lambda); Topocentric.Beta = Math.Atan(cosTopocentricLambda * (sinBeta - sinpi * (S * cose - C * sine * sintheta)) / N); Topocentric.Semidiameter = Math.Asin(cosTopocentricLambda * Math.Cos(Topocentric.Beta) * Math.Sin(Semidiameter) / N); //Convert back to degrees Topocentric.Semidiameter = CT.R2D(Topocentric.Semidiameter); Topocentric.Lambda = CT.M360(CT.R2D(Topocentric.Lambda)); Topocentric.Beta = CT.R2D(Topocentric.Beta); return(Topocentric); }
public static COR AdjustPositionUsingMotionInSpace(double r, double DeltaR, double t, double Alpha, double Delta, double PMAlpha, double PMDelta) { //Convert DeltaR from km/s to Parsecs / Year DeltaR /= 977792; //Convert from seconds of time to Radians / Year PMAlpha /= 13751; //Convert from seconds of arc to Radians / Year PMDelta /= 206265; //Now convert to radians Alpha = CT.H2R(Alpha); Delta = CT.D2R(Delta); double x = r * Math.Cos(Delta) * Math.Cos(Alpha); double y = r * Math.Cos(Delta) * Math.Sin(Alpha); double z = r * Math.Sin(Delta); double DeltaX = x / r * DeltaR - z * PMDelta * Math.Cos(Alpha) - y * PMAlpha; double DeltaY = y / r * DeltaR - z * PMDelta * Math.Sin(Alpha) + x * PMAlpha; double DeltaZ = z / r * DeltaR + r * PMDelta * Math.Cos(Delta); x += t * DeltaX; y += t * DeltaY; z += t * DeltaZ; COR @value = new COR(); @value.X = CT.R2H(Math.Atan2(y, x)); if (@value.X < 0) { @value.X += 24; } @value.Y = CT.R2D(Math.Atan2(z, Math.Sqrt(x * x + y * y))); return(@value); }
//Static methods public static COR PrecessEquatorial(double Alpha, double Delta, double JD0, double JD) { double T = (JD0 - 2451545.0) / 36525; double Tsquared = T * T; double t = (JD - JD0) / 36525; double tsquared = t * t; double tcubed = tsquared * t; //Now convert to radians Alpha = CT.H2R(Alpha); Delta = CT.D2R(Delta); double sigma = (2306.2181 + 1.39656 * T - 0.000139 * Tsquared) * t + (0.30188 - 0.0000344 * T) * tsquared + 0.017988 * tcubed; sigma = CT.D2R(CT.DMS2D(0, 0, sigma)); double zeta = (2306.2181 + 1.39656 * T - 0.000138 * Tsquared) * t + (1.09468 + 0.000066 * T) * tsquared + 0.018203 * tcubed; zeta = CT.D2R(CT.DMS2D(0, 0, zeta)); double phi = (2004.3109 - 0.8533 * T - 0.000217 * Tsquared) * t - (0.42665 + 0.000217 * T) * tsquared - 0.041833 * tcubed; phi = CT.D2R(CT.DMS2D(0, 0, phi)); double A = Math.Cos(Delta) * Math.Sin(Alpha + sigma); double B = Math.Cos(phi) * Math.Cos(Delta) * Math.Cos(Alpha + sigma) - Math.Sin(phi) * Math.Sin(Delta); double C = Math.Sin(phi) * Math.Cos(Delta) * Math.Cos(Alpha + sigma) + Math.Cos(phi) * Math.Sin(Delta); COR @value = new COR(); @value.X = CT.R2H(Math.Atan2(A, B) + zeta); if (@value.X < 0) { @value.X += 24; } @value.Y = CT.R2D(Math.Asin(C)); return(@value); }
public static double PositionAngle(double alpha1, double delta1, double alpha2, double delta2) { double Alpha1; double Delta1; double Alpha2; double Delta2; Delta1 = CT.D2R(delta1); Delta2 = CT.D2R(delta2); Alpha1 = CT.H2R(alpha1); Alpha2 = CT.H2R(alpha2); double DeltaAlpha = Alpha1 - Alpha2; double demoninator = Math.Cos(Delta2) * Math.Tan(Delta1) - Math.Sin(Delta2) * Math.Cos(DeltaAlpha); double numerator = Math.Sin(DeltaAlpha); double @value = Math.Atan2(numerator, demoninator); @value = CT.R2D(@value); return(@value); }
//Static methods //////////////////////////// Implementation /////////////////////////////////// public static double Separation(double Alpha1, double Delta1, double Alpha2, double Delta2) { Delta1 = CT.D2R(Delta1); Delta2 = CT.D2R(Delta2); Alpha1 = CT.H2R(Alpha1); Alpha2 = CT.H2R(Alpha2); double x = Math.Cos(Delta1) * Math.Sin(Delta2) - Math.Sin(Delta1) * Math.Cos(Delta2) * Math.Cos(Alpha2 - Alpha1); double y = Math.Cos(Delta2) * Math.Sin(Alpha2 - Alpha1); double z = Math.Sin(Delta1) * Math.Sin(Delta2) + Math.Cos(Delta1) * Math.Cos(Delta2) * Math.Cos(Alpha2 - Alpha1); double @value = Math.Atan2(Math.Sqrt(x * x + y * y), z); @value = CT.R2D(@value); if (@value < 0) { @value += 180; } return(@value); }
public static COR PrecessEquatorialFK4(double Alpha, double Delta, double JD0, double JD) { double T = (JD0 - 2415020.3135) / 36524.2199; double t = (JD - JD0) / 36524.2199; double tsquared = t * t; double tcubed = tsquared * t; //Now convert to radians Alpha = CT.H2R(Alpha); Delta = CT.D2R(Delta); double sigma = (2304.250 + 1.396 * T) * t + 0.302 * tsquared + 0.018 * tcubed; sigma = CT.D2R(CT.DMS2D(0, 0, sigma)); double zeta = 0.791 * tsquared + 0.001 * tcubed; zeta = CT.D2R(CT.DMS2D(0, 0, zeta)); zeta += sigma; double phi = (2004.682 - 0.853 * T) * t - 0.426 * tsquared - 0.042 * tcubed; phi = CT.D2R(CT.DMS2D(0, 0, phi)); double A = Math.Cos(Delta) * Math.Sin(Alpha + sigma); double B = Math.Cos(phi) * Math.Cos(Delta) * Math.Cos(Alpha + sigma) - Math.Sin(phi) * Math.Sin(Delta); double C = Math.Sin(phi) * Math.Cos(Delta) * Math.Cos(Alpha + sigma) + Math.Cos(phi) * Math.Sin(Delta); COR @value = new COR(); @value.X = CT.R2H(Math.Atan2(A, B) + zeta); if (@value.X < 0) { @value.X += 24; } @value.Y = CT.R2D(Math.Asin(C)); return(@value); }
public static double DistanceFromGreatArc(double Alpha1, double Delta1, double Alpha2, double Delta2, double Alpha3, double Delta3) { Delta1 = CT.D2R(Delta1); Delta2 = CT.D2R(Delta2); Delta3 = CT.D2R(Delta3); Alpha1 = CT.H2R(Alpha1); Alpha2 = CT.H2R(Alpha2); Alpha3 = CT.H2R(Alpha3); double X1 = Math.Cos(Delta1) * Math.Cos(Alpha1); double X2 = Math.Cos(Delta2) * Math.Cos(Alpha2); double Y1 = Math.Cos(Delta1) * Math.Sin(Alpha1); double Y2 = Math.Cos(Delta2) * Math.Sin(Alpha2); double Z1 = Math.Sin(Delta1); double Z2 = Math.Sin(Delta2); double A = Y1 * Z2 - Z1 * Y2; double B = Z1 * X2 - X1 * Z2; double C = X1 * Y2 - Y1 * X2; double m = Math.Tan(Alpha3); double n = Math.Tan(Delta3) / Math.Cos(Alpha3); double @value = Math.Asin((A + B * m + C * n) / (Math.Sqrt(A * A + B * B + C * C) * Math.Sqrt(1 + m * m + n * n))); @value = CT.R2D(@value); if (@value < 0) { @value = Math.Abs(@value); } return(@value); }
//Static methods //////////////////////////////// Implementation /////////////////////////////// public static CAASaturnRingDetails Calculate(double JD) { //What will be the return value CAASaturnRingDetails details = new CAASaturnRingDetails(); double T = (JD - 2451545) / 36525; double T2 = T * T; //Step 1. Calculate the inclination of the plane of the ring and the longitude of the ascending node referred to the ecliptic and mean equinox of the date double i = 28.075216 - 0.012998 * T + 0.000004 * T2; double irad = CT.D2R(i); double omega = 169.508470 + 1.394681 * T + 0.000412 * T2; double omegarad = CT.D2R(omega); //Step 2. Calculate the heliocentric longitude, latitude and radius vector of the Earth in the FK5 system double l0 = CAAEarth.EclipticLongitude(JD); double b0 = CAAEarth.EclipticLatitude(JD); l0 += CAAFK5.CorrectionInLongitude(l0, b0, JD); double l0rad = CT.D2R(l0); b0 += CAAFK5.CorrectionInLatitude(l0, JD); double b0rad = CT.D2R(b0); double R = CAAEarth.RadiusVector(JD); //Step 3. Calculate the corresponding coordinates l,b,r for Saturn but for the instance t-lightraveltime double DELTA = 9; double PreviousEarthLightTravelTime = 0; double EarthLightTravelTime = ELL.DistanceToLightTime(DELTA); double JD1 = JD - EarthLightTravelTime; bool bIterate = true; double x = 0; double y = 0; double z = 0; double l = 0; double b = 0; double r = 0; while (bIterate) { //Calculate the position of Saturn l = CAASaturn.EclipticLongitude(JD1); b = CAASaturn.EclipticLatitude(JD1); l += CAAFK5.CorrectionInLongitude(l, b, JD1); b += CAAFK5.CorrectionInLatitude(l, JD1); double lrad = CT.D2R(l); double brad = CT.D2R(b); r = CAASaturn.RadiusVector(JD1); //Step 4 x = r * Math.Cos(brad) * Math.Cos(lrad) - R * Math.Cos(l0rad); y = r * Math.Cos(brad) * Math.Sin(lrad) - R * Math.Sin(l0rad); z = r * Math.Sin(brad) - R * Math.Sin(b0rad); DELTA = Math.Sqrt(x * x + y * y + z * z); EarthLightTravelTime = ELL.DistanceToLightTime(DELTA); //Prepare for the next loop around bIterate = (Math.Abs(EarthLightTravelTime - PreviousEarthLightTravelTime) > 2E-6); //2E-6 corresponds to 0.17 of a second if (bIterate) { JD1 = JD - EarthLightTravelTime; PreviousEarthLightTravelTime = EarthLightTravelTime; } } //Step 5. Calculate Saturn's geocentric Longitude and Latitude double lambda = Math.Atan2(y, x); double beta = Math.Atan2(z, Math.Sqrt(x * x + y * y)); //Step 6. Calculate B, a and b details.B = Math.Asin(Math.Sin(irad) * Math.Cos(beta) * Math.Sin(lambda - omegarad) - Math.Cos(irad) * Math.Sin(beta)); details.a = 375.35 / DELTA; details.b = details.a * Math.Sin(Math.Abs(details.B)); details.B = CT.R2D(details.B); //Step 7. Calculate the longitude of the ascending node of Saturn's orbit double N = 113.6655 + 0.8771 * T; double Nrad = CT.D2R(N); double ldash = l - 0.01759 / r; double ldashrad = CT.D2R(ldash); double bdash = b - 0.000764 * Math.Cos(ldashrad - Nrad) / r; double bdashrad = CT.D2R(bdash); //Step 8. Calculate Bdash details.Bdash = CT.R2D(Math.Asin(Math.Sin(irad) * Math.Cos(bdashrad) * Math.Sin(ldashrad - omegarad) - Math.Cos(irad) * Math.Sin(bdashrad))); //Step 9. Calculate DeltaU double U1 = Math.Atan2(Math.Sin(irad) * Math.Sin(bdashrad) + Math.Cos(irad) * Math.Cos(bdashrad) * Math.Sin(ldashrad - omegarad), Math.Cos(bdashrad) * Math.Cos(ldashrad - omegarad)); double U2 = Math.Atan2(Math.Sin(irad) * Math.Sin(beta) + Math.Cos(irad) * Math.Cos(beta) * Math.Sin(lambda - omegarad), Math.Cos(beta) * Math.Cos(lambda - omegarad)); details.DeltaU = CT.R2D(Math.Abs(U1 - U2)); //Step 10. Calculate the Nutations double Obliquity = CAANutation.TrueObliquityOfEcliptic(JD); double NutationInLongitude = CAANutation.NutationInLongitude(JD); //Step 11. Calculate the Ecliptical longitude and latitude of the northern pole of the ring plane double lambda0 = omega - 90; double beta0 = 90 - i; //Step 12. Correct lambda and beta for the aberration of Saturn lambda += CT.D2R(0.005693 * Math.Cos(l0rad - lambda) / Math.Cos(beta)); beta += CT.D2R(0.005693 * Math.Sin(l0rad - lambda) * Math.Sin(beta)); //Step 13. Add nutation in longitude to lambda0 and lambda //double NLrad = CAACoordinateTransformation::DegreesToRadians(NutationInLongitude/3600); lambda = CT.R2D(lambda); lambda += NutationInLongitude / 3600; lambda = CT.M360(lambda); lambda0 += NutationInLongitude / 3600; lambda0 = CT.M360(lambda0); //Step 14. Convert to equatorial coordinates beta = CT.R2D(beta); COR GeocentricEclipticSaturn = CT.Ec2Eq(lambda, beta, Obliquity); double alpha = CT.H2R(GeocentricEclipticSaturn.X); double delta = CT.D2R(GeocentricEclipticSaturn.Y); COR GeocentricEclipticNorthPole = CT.Ec2Eq(lambda0, beta0, Obliquity); double alpha0 = CT.H2R(GeocentricEclipticNorthPole.X); double delta0 = CT.D2R(GeocentricEclipticNorthPole.Y); //Step 15. Calculate the Position angle details.P = CT.R2D(Math.Atan2(Math.Cos(delta0) * Math.Sin(alpha0 - alpha), Math.Sin(delta0) * Math.Cos(delta) - Math.Cos(delta0) * Math.Sin(delta) * Math.Cos(alpha0 - alpha))); return(details); }
//Static methods //////////////////////////////// Implementation /////////////////////////////// public static CAAPhysicalMarsDetails Calculate(double JD) { //What will be the return value CAAPhysicalMarsDetails details = new CAAPhysicalMarsDetails(); //Step 1 double T = (JD - 2451545) / 36525; double Lambda0 = 352.9065 + 1.17330 * T; double Lambda0rad = CT.D2R(Lambda0); double Beta0 = 63.2818 - 0.00394 * T; double Beta0rad = CT.D2R(Beta0); //Step 2 double l0 = CAAEarth.EclipticLongitude(JD); double l0rad = CT.D2R(l0); double b0 = CAAEarth.EclipticLatitude(JD); double b0rad = CT.D2R(b0); double R = CAAEarth.RadiusVector(JD); double PreviousLightTravelTime = 0; double LightTravelTime = 0; double x = 0; double y = 0; double z = 0; bool bIterate = true; double DELTA = 0; double l = 0; double lrad = 0; double b = 0; double brad = 0; double r = 0; while (bIterate) { double JD2 = JD - LightTravelTime; //Step 3 l = CAAMars.EclipticLongitude(JD2); lrad = CT.D2R(l); b = CAAMars.EclipticLatitude(JD2); brad = CT.D2R(b); r = CAAMars.RadiusVector(JD2); //Step 4 x = r * Math.Cos(brad) * Math.Cos(lrad) - R * Math.Cos(l0rad); y = r * Math.Cos(brad) * Math.Sin(lrad) - R * Math.Sin(l0rad); z = r * Math.Sin(brad) - R * Math.Sin(b0rad); DELTA = Math.Sqrt(x * x + y * y + z * z); LightTravelTime = ELL.DistanceToLightTime(DELTA); //Prepare for the next loop around bIterate = (Math.Abs(LightTravelTime - PreviousLightTravelTime) > 2E-6); //2E-6 correponds to 0.17 of a second if (bIterate) { PreviousLightTravelTime = LightTravelTime; } } //Step 5 double lambdarad = Math.Atan2(y, x); double lambda = CT.R2D(lambdarad); double betarad = Math.Atan2(z, Math.Sqrt(x * x + y * y)); double beta = CT.R2D(betarad); //Step 6 details.DE = CT.R2D(Math.Asin(-Math.Sin(Beta0rad) * Math.Sin(betarad) - Math.Cos(Beta0rad) * Math.Cos(betarad) * Math.Cos(Lambda0rad - lambdarad))); //Step 7 double N = 49.5581 + 0.7721 * T; double Nrad = CT.D2R(N); double ldash = l - 0.00697 / r; double ldashrad = CT.D2R(ldash); double bdash = b - 0.000225 * (Math.Cos(lrad - Nrad) / r); double bdashrad = CT.D2R(bdash); //Step 8 details.DS = CT.R2D(Math.Asin(-Math.Sin(Beta0rad) * Math.Sin(bdashrad) - Math.Cos(Beta0rad) * Math.Cos(bdashrad) * Math.Cos(Lambda0rad - ldashrad))); //Step 9 double W = CT.M360(11.504 + 350.89200025 * (JD - LightTravelTime - 2433282.5)); //Step 10 double e0 = CAANutation.MeanObliquityOfEcliptic(JD); double e0rad = CT.D2R(e0); COR PoleEquatorial = CT.Ec2Eq(Lambda0, Beta0, e0); double alpha0rad = CT.H2R(PoleEquatorial.X); double delta0rad = CT.D2R(PoleEquatorial.Y); //Step 11 double u = y * Math.Cos(e0rad) - z * Math.Sin(e0rad); double v = y * Math.Sin(e0rad) + z * Math.Cos(e0rad); double alpharad = Math.Atan2(u, x); double alpha = CT.R2H(alpharad); double deltarad = Math.Atan2(v, Math.Sqrt(x * x + u * u)); double delta = CT.R2D(deltarad); double xi = Math.Atan2(Math.Sin(delta0rad) * Math.Cos(deltarad) * Math.Cos(alpha0rad - alpharad) - Math.Sin(deltarad) * Math.Cos(delta0rad), Math.Cos(deltarad) * Math.Sin(alpha0rad - alpharad)); //Step 12 details.w = CT.M360(W - CT.R2D(xi)); //Step 13 double NutationInLongitude = CAANutation.NutationInLongitude(JD); double NutationInObliquity = CAANutation.NutationInObliquity(JD); //Step 14 lambda += 0.005693 * Math.Cos(l0rad - lambdarad) / Math.Cos(betarad); beta += 0.005693 * Math.Sin(l0rad - lambdarad) * Math.Sin(betarad); //Step 15 Lambda0 += NutationInLongitude / 3600; Lambda0rad = CT.D2R(Lambda0); lambda += NutationInLongitude / 3600; lambdarad = CT.D2R(lambda); e0 += NutationInObliquity / 3600; e0rad = CT.D2R(e0rad); //Step 16 COR ApparentPoleEquatorial = CT.Ec2Eq(Lambda0, Beta0, e0); double alpha0dash = CT.H2R(ApparentPoleEquatorial.X); double delta0dash = CT.D2R(ApparentPoleEquatorial.Y); COR ApparentMars = CT.Ec2Eq(lambda, beta, e0); double alphadash = CT.H2R(ApparentMars.X); double deltadash = CT.D2R(ApparentMars.Y); //Step 17 details.P = CT.M360(CT.R2D(Math.Atan2(Math.Cos(delta0dash) * Math.Sin(alpha0dash - alphadash), Math.Sin(delta0dash) * Math.Cos(deltadash) - Math.Cos(delta0dash) * Math.Sin(deltadash) * Math.Cos(alpha0dash - alphadash)))); //Step 18 double SunLambda = CAASun.GeometricEclipticLongitude(JD); double SunBeta = CAASun.GeometricEclipticLatitude(JD); COR SunEquatorial = CT.Ec2Eq(SunLambda, SunBeta, e0); details.X = MIFR.PositionAngle(SunEquatorial.X, SunEquatorial.Y, alpha, delta); //Step 19 details.d = 9.36 / DELTA; details.k = IFR.IlluminatedFraction2(r, R, DELTA); details.q = (1 - details.k) * details.d; return(details); }