private static double getCorrection(double D, double a1, double a2, double a3, double d1, double d2, double d3, double siderealTime, double h0, double longitude, double latitude, double m0, bool transit)
{
double deltaM = 0;
double PHI = siderealTime + 360.985647 * m0;
double n = m0 + GPDynamicTime.GetDeltaT(D) / 86400;
double alpha = GPAstroEngine.interpolation(a1, a2, a3, n);
double delta = GPAstroEngine.interpolation(d1, d2, d3, n);
double H = GPMath.putIn180(PHI - longitude - alpha);
double h = 0;
if (transit)
{
deltaM = -H / 360;
}
else
{
double sinH = GPMath.sinDeg(latitude) * GPMath.sinDeg(delta) + GPMath.cosDeg(latitude) * GPMath.cosDeg(delta) * GPMath.cosDeg(H);
h = GPMath.arcsinDeg(sinH);
deltaM = (h - h0) / (360 * GPMath.cosDeg(delta) * GPMath.cosDeg(latitude) * GPMath.sinDeg(H));
}
return(deltaM);
}