/*************************************/
/* sun functions */
/* */
/* sun longitude */
/* sunrise, sunset time */
/* */
/*************************************/
//////////////////////////////////////////////////////////////////////////
//
// VCTIME vct [in] - valid must be each member of this structure
//
// from vct uses members: year, month, day
// double is in range 0.0 - 1.0
private void SunPosition(GregorianDateTime vct, GCEarthData ed, double dayHours)
{
double DG = GCMath.PI / 180;
double RAD = 180 / GCMath.PI;
double dLatitude = ed.latitudeDeg;
double dLongitude = ed.longitudeDeg;
// mean ecliptic longitude of the sun
meanLongitudeOfSun = GCSunData.SunGetMeanLong(vct.year, vct.month, vct.day) + (360 / 365.25) * dayHours / 360.0;
// ecliptic longitude of perigee
double elp = GCSunData.SunGetPerigee(vct.year, vct.month, vct.day);
// mean anomaly of the sun
double mas = meanLongitudeOfSun - elp;
// ecliptic longitude of the sun
double els = 0.0;
this.longitudeDeg = els = meanLongitudeOfSun + 1.915 * Math.Sin(mas * DG) + 0.02 * Math.Sin(2 * DG * mas);
// declination of the sun
this.declinationDeg = RAD * Math.Asin(0.39777 * Math.Sin(els * DG));
// right ascension of the sun
this.rightAscensionDeg = els - RAD * Math.Atan2(Math.Sin(2 * els * DG), 23.2377 + Math.Cos(2 * DG * els));
// equation of time
equationOfTime = this.rightAscensionDeg - meanLongitudeOfSun;
}
//
// takes values year, month, day, shour, TimeZone
//
public static double GetSunLongitude(GregorianDateTime vct)
{
// double mel = 0.0;
double DG = GCMath.PI / 180;
double RAD = 180 / GCMath.PI;
// mean ecliptic longitude of the sun
double mel = GCSunData.SunGetMeanLong(vct.year, vct.month, vct.day) + (360 / 365.25) * (vct.shour - 0.5 - vct.TimezoneHours / 24.0);
// ecliptic longitude of perigee
double elp = GCSunData.SunGetPerigee(vct.year, vct.month, vct.day);
// mean anomaly of the sun
double mas = mel - elp;
// ecliptic longitude of the sun
//double els = 0.0;
return(mel + 1.915 * Math.Sin(mas * DG) + 0.02 * Math.Sin(2 * DG * mas));
}