public static double SummerSolstice(int Year)
{
//calculate the approximate date
double JDE = 0;
if (Year <= 1000)
{
double Y = Year / 1000.0;
double Ysquared = Y * Y;
double Ycubed = Ysquared * Y;
double Y4 = Ycubed * Y;
JDE = 1721233.25401 + 365241.72562 * Y - 0.05323 * Ysquared + 0.00907 * Ycubed + 0.00025 * Y4;
}
else
{
double Y = (Year - 2000) / 1000.0;
double Ysquared = Y * Y;
double Ycubed = Ysquared * Y;
double Y4 = Ycubed * Y;
JDE = 2451716.56767 + 365241.62603 * Y + 0.00325 * Ysquared + 0.00888 * Ycubed - 0.00030 * Y4;
}
double Correction;
do
{
double SunLongitude = CAASun.ApparentEclipticLongitude(JDE);
Correction = 58 * Math.Sin(CAACoordinateTransformation.DegreesToRadians(90 - SunLongitude));
JDE += Correction;
}while (Math.Abs(Correction) > 0.00001); //Corresponds to an error of 0.86 of a second
return(JDE);
}
//Static methods
//////////////////////////////// Implementation ///////////////////////////////
public static double SpringEquinox(int Year)
{
//calculate the approximate date
double JDE = 0;
if (Year <= 1000)
{
double Y = Year / 1000.0;
double Ysquared = Y * Y;
double Ycubed = Ysquared * Y;
double Y4 = Ycubed * Y;
JDE = 1721139.29189 + 365242.13740 * Y + 0.06134 * Ysquared + 0.00111 * Ycubed - 0.00071 * Y4;
}
else
{
double Y = (Year - 2000) / 1000.0;
double Ysquared = Y * Y;
double Ycubed = Ysquared * Y;
double Y4 = Ycubed * Y;
JDE = 2451623.80984 + 365242.37404 * Y + 0.05169 * Ysquared - 0.00411 * Ycubed - 0.00057 * Y4;
}
double Correction;
do
{
double SunLongitude = CAASun.ApparentEclipticLongitude(JDE);
Correction = 58 * Math.Sin(CAACoordinateTransformation.DegreesToRadians(-SunLongitude));
JDE += Correction;
}while (Math.Abs(Correction) > 0.00001); //Corresponds to an error of 0.86 of a second
return(JDE);
}
public static double WinterSolstice(int Year)
{
//calculate the approximate date
double JDE = 0;
if (Year <= 1000)
{
double Y = Year / 1000.0;
double Ysquared = Y * Y;
double Ycubed = Ysquared * Y;
double Y4 = Ycubed * Y;
JDE = 1721414.39987 + 365242.88257 * Y - 0.00769 * Ysquared - 0.00933 * Ycubed - 0.00006 * Y4;
}
else
{
double Y = (Year - 2000) / 1000.0;
double Ysquared = Y * Y;
double Ycubed = Ysquared * Y;
double Y4 = Ycubed * Y;
JDE = 2451900.05952 + 365242.74049 * Y - 0.06223 * Ysquared - 0.00823 * Ycubed + 0.00032 * Y4;
}
double Correction;
do
{
double SunLongitude = CAASun.ApparentEclipticLongitude(JDE);
Correction = 58 * Math.Sin(CAACoordinateTransformation.DegreesToRadians(270 - SunLongitude));
JDE += Correction;
}while (Math.Abs(Correction) > 0.00001); //Corresponds to an error of 0.86 of a second
return(JDE);
}
public static double AutumnEquinox(int Year)
{
//calculate the approximate date
double JDE = 0;
if (Year <= 1000)
{
double Y = Year / 1000.0;
double Ysquared = Y * Y;
double Ycubed = Ysquared * Y;
double Y4 = Ycubed * Y;
JDE = 1721325.70455 + 365242.49558 * Y - 0.11677 * Ysquared - 0.00297 * Ycubed + 0.00074 * Y4;
}
else
{
double Y = (Year - 2000) / 1000.0;
double Ysquared = Y * Y;
double Ycubed = Ysquared * Y;
double Y4 = Ycubed * Y;
JDE = 2451810.21715 + 365242.01767 * Y - 0.11575 * Ysquared + 0.00337 * Ycubed + 0.00078 * Y4;
}
double Correction;
do
{
double SunLongitude = CAASun.ApparentEclipticLongitude(JDE);
Correction = 58 * Math.Sin(CAACoordinateTransformation.DegreesToRadians(180 - SunLongitude));
JDE += Correction;
}while (Math.Abs(Correction) > 0.00001); //Corresponds to an error of 0.86 of a second
return(JDE);
}
//Static methods
///////////////////////// Implementation //////////////////////////////////////
public static double Calculate(double JD)
{
double rho = (JD - 2451545) / 365250;
double rhosquared = rho * rho;
double rhocubed = rhosquared * rho;
double rho4 = rhocubed * rho;
double rho5 = rho4 * rho;
//Calculate the Suns mean longitude
double L0 = CT.M360(280.4664567 + 360007.6982779 * rho + 0.03032028 * rhosquared + rhocubed / 49931 - rho4 / 15300 - rho5 / 2000000);
//Calculate the Suns apparent right ascension
double SunLong = CAASun.ApparentEclipticLongitude(JD);
double SunLat = CAASun.ApparentEclipticLatitude(JD);
double epsilon = CAANutation.TrueObliquityOfEcliptic(JD);
COR Equatorial = CT.Ec2Eq(SunLong, SunLat, epsilon);
epsilon = CT.D2R(epsilon);
double E = L0 - 0.0057183 - Equatorial.X * 15 + CT.DMS2D(0, 0, CAANutation.NutationInLongitude(JD)) * Math.Cos(epsilon);
if (E > 180)
{
E = -(360 - E);
}
E *= 4; //Convert to minutes of time
return(E);
}
public static CAASelenographicMoonDetails CalculateSelenographicPositionOfSun(double JD)
{
double R = CAAEarth.RadiusVector(JD) * 149597970;
double Delta = CAAMoon.RadiusVector(JD);
double lambda0 = CAASun.ApparentEclipticLongitude(JD);
double lambda = CAAMoon.EclipticLongitude(JD);
double beta = CAAMoon.EclipticLatitude(JD);
double lambdah = CAACoordinateTransformation.MapTo0To360Range(lambda0 + 180 + Delta / R * 57.296 * Math.Cos(CAACoordinateTransformation.DegreesToRadians(beta)) * Math.Sin(CAACoordinateTransformation.DegreesToRadians(lambda0 - lambda)));
double betah = Delta / R * beta;
//What will be the return value
CAASelenographicMoonDetails details = new CAASelenographicMoonDetails();
//Calculate the optical libration
double omega = 0;
double DeltaU = 0;
double sigma = 0;
double I = 0;
double rho = 0;
double ldash0 = 0;
double bdash0 = 0;
double ldash20 = 0;
double bdash20 = 0;
double epsilon = 0;
CalculateOpticalLibration(JD, lambdah, betah, ref ldash0, ref bdash0, ref ldash20, ref bdash20, ref epsilon, ref omega, ref DeltaU, ref sigma, ref I, ref rho);
details.l0 = ldash0 + ldash20;
details.b0 = bdash0 + bdash20;
details.c0 = CAACoordinateTransformation.MapTo0To360Range(450 - details.l0);
return(details);
}