//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 int DaysInYear(int Year)
{
//Find the previous civil year corresponding to the specified jewish year
int CivilYear = Year - 3761;
//Find the date of the next Jewish Year in that civil year
CAACalendarDate CurrentPesach = DateOfPesach(CivilYear);
bool bGregorian = CAADate.AfterPapalReform(CivilYear, CurrentPesach.Month, CurrentPesach.Day);
CAADate CurrentYear = new CAADate(CivilYear, CurrentPesach.Month, CurrentPesach.Day, bGregorian);
CAACalendarDate NextPesach = DateOfPesach(CivilYear + 1);
CAADate NextYear = new CAADate(CivilYear + 1, NextPesach.Month, NextPesach.Day, bGregorian);
return((int)(NextYear - CurrentYear));
}
//Static methods
////////////////////////////////// Implementation /////////////////////////////
public static double DeltaT(double JD)
{
//Construct a CAADate from the julian day
CAADate date = new CAADate(JD, CAADate.AfterPapalReform(JD));
double y = date.FractionalYear();
double T = (y - 2000) / 100;
double Delta;
if (y < 948)
{
Delta = 2177 + (497 * T) + (44.1 * T * T);
}
else if (y < 1620)
{
Delta = 102 + (102 * T) + (25.3 * T * T);
}
else if (y < 1998)
{
int Index = (int)((y - 1620) / 2);
Debug.Assert(Index < GlobalMembersStdafx.DeltaTTable.Length);
y = y / 2 - Index - 810;
Delta = (GlobalMembersStdafx.DeltaTTable[Index] + (GlobalMembersStdafx.DeltaTTable[Index + 1] - GlobalMembersStdafx.DeltaTTable[Index]) * y);
}
else if (y <= 2000)
{
int nLookupSize = GlobalMembersStdafx.DeltaTTable.Length;
Delta = GlobalMembersStdafx.DeltaTTable[nLookupSize - 1];
}
else if (y < 2100)
{
Delta = 102 + (102 * T) + (25.3 * T * T) + 0.37 * (y - 2100);
}
else
{
Delta = 102 + (102 * T) + (25.3 * T * T);
}
return(Delta);
}
