private static MoonPosition GetMoonPosition(DateTime date, double lat, double lng, Celestial cel)
{
//Set UTC date integrity
date = new DateTime(date.Year, date.Month, date.Day, date.Hour, date.Minute, date.Second, DateTimeKind.Utc);
double d = JulianConversions.GetJulian_Epoch2000(date);
//Ch 47
double JDE = JulianConversions.GetJulian(date); //Get julian
double T = (JDE - 2451545) / 36525; //Get dynamic time.
double[] LDMNF = Get_Moon_LDMNF(T);
CelCoords c = GetMoonCoords(d, cel, LDMNF, T);
Distance dist = GetMoonDistance(date);
double lw = rad * -lng;
double phi = rad * lat;
double H = rad * Get_Sidereal_Time(JDE, lw) - lw - c.ra;
double ra = c.ra; //Adjust current RA formula to avoid needless RAD conversions
double dec = c.dec; //Adjust current RA formula to avoid needless RAD conversions
//Adjust for parallax (low accuracry increases may not be worth cost)
//Investigate
double pSinE = Get_pSinE(dec, dist.Meters) * Math.PI / 180;
double pCosE = Get_pCosE(dec, dist.Meters) * Math.PI / 180;
double cRA = Parallax_RA(dist.Meters, H, pCosE, dec, ra);
double tDEC = Parallax_Dec(dist.Meters, H, pCosE, pSinE, dec, cRA);
double tRA = ra - cRA;
dec = tDEC;
ra = tRA;
//Get true altitude
double h = altitude(H, phi, dec);
// formula 14.1 of "Astronomical Algorithms" 2nd edition by Jean Meeus (Willmann-Bell, Richmond) 1998.
double pa = Math.Atan2(Math.Sin(H), Math.Tan(phi) * Math.Cos(dec) - Math.Sin(dec) * Math.Cos(H));
//altitude correction for refraction
h = h + astroRefraction(h);
MoonPosition mp = new MoonPosition();
mp.Azimuth = azimuth(H, phi, dec);
mp.Altitude = h / Math.PI * 180;
mp.Distance = dist;
mp.ParallacticAngle = pa;
double horParal = 8.794 / (dist.Meters / 149.59787E6); // horizontal parallax (arcseconds), Meeus S. 263
double p = Math.Asin(Math.Cos(h) * Math.Sin(horParal / 3600)); // parallax in altitude (degrees)
p *= 1000;
mp.ParallaxCorection = p;
mp.Altitude *= rad;
return(mp);
}
public static void GetMoonIllumination(DateTime date, Celestial c, double lat, double lng)
{
date = new DateTime(date.Year, date.Month, date.Day, date.Hour, date.Minute, date.Second, DateTimeKind.Utc);
double d = JulianConversions.GetJulian_Epoch2000(date);
CelCoords s = GetSunCoords(d);
double JDE = JulianConversions.GetJulian(date); //Get julian
double T = (JDE - 2451545) / 36525; //Get dynamic time.
double[] LDMNF = Get_Moon_LDMNF(T);
CelCoords m = GetMoonCoords(d, c, LDMNF, T);
double sdist = 149598000,
phi = Math.Acos(Math.Sin(s.dec) * Math.Sin(m.dec) + Math.Cos(s.dec) * Math.Cos(m.dec) * Math.Cos(s.ra - m.ra)),
inc = Math.Atan2(sdist * Math.Sin(phi), m.dist - sdist * Math.Cos(phi)),
angle = Math.Atan2(Math.Cos(s.dec) * Math.Sin(s.ra - m.ra), Math.Sin(s.dec) * Math.Cos(m.dec) -
Math.Cos(s.dec) * Math.Sin(m.dec) * Math.Cos(s.ra - m.ra));
MoonIllum mi = new MoonIllum();
mi.Fraction = (1 + Math.Cos(inc)) / 2;
mi.Phase = 0.5 + 0.5 * inc * (angle < 0 ? -1 : 1) / Math.PI;
mi.Angle = angle;
c.MoonIllum = mi;
string moonName = "";
int moonDate = 0;
//GET PHASE NAME
//CHECK MOON AT BEGINNING AT END OF DAY TO GET DAY PHASE
DateTime dMon = new DateTime(date.Year, date.Month, 1);
for (int x = 1; x <= date.Day; x++)
{
DateTime nDate = new DateTime(dMon.Year, dMon.Month, x, 0, 0, 0, DateTimeKind.Utc);
d = JulianConversions.GetJulian_Epoch2000(nDate);
s = GetSunCoords(d);
JDE = JulianConversions.GetJulian(nDate); //Get julian
T = (JDE - 2451545) / 36525; //Get dynamic time.
LDMNF = Get_Moon_LDMNF(T);
m = GetMoonCoords(d, c, LDMNF, T);
phi = Math.Acos(Math.Sin(s.dec) * Math.Sin(m.dec) + Math.Cos(s.dec) * Math.Cos(m.dec) * Math.Cos(s.ra - m.ra));
inc = Math.Atan2(sdist * Math.Sin(phi), m.dist - sdist * Math.Cos(phi));
angle = Math.Atan2(Math.Cos(s.dec) * Math.Sin(s.ra - m.ra), Math.Sin(s.dec) * Math.Cos(m.dec) -
Math.Cos(s.dec) * Math.Sin(m.dec) * Math.Cos(s.ra - m.ra));
double startPhase = 0.5 + 0.5 * inc * (angle < 0 ? -1 : 1) / Math.PI;
nDate = new DateTime(dMon.Year, dMon.Month, x, 23, 59, 59, DateTimeKind.Utc);
d = JulianConversions.GetJulian_Epoch2000(nDate);
s = GetSunCoords(d);
JDE = JulianConversions.GetJulian(nDate); //Get julian
T = (JDE - 2451545) / 36525; //Get dynamic time.
LDMNF = Get_Moon_LDMNF(T);
m = GetMoonCoords(d, c, LDMNF, T);
phi = Math.Acos(Math.Sin(s.dec) * Math.Sin(m.dec) + Math.Cos(s.dec) * Math.Cos(m.dec) * Math.Cos(s.ra - m.ra));
inc = Math.Atan2(sdist * Math.Sin(phi), m.dist - sdist * Math.Cos(phi));
angle = Math.Atan2(Math.Cos(s.dec) * Math.Sin(s.ra - m.ra), Math.Sin(s.dec) * Math.Cos(m.dec) -
Math.Cos(s.dec) * Math.Sin(m.dec) * Math.Cos(s.ra - m.ra));
double endPhase = 0.5 + 0.5 * inc * (angle < 0 ? -1 : 1) / Math.PI;
//Determine Moon Name.
if (startPhase <= .5 && endPhase >= .5)
{
moonDate = x;
moonName = GetMoonName(dMon.Month, moonName);
}
//Get Moon Name (month, string);
//Get Moon Phase Name
if (date.Day == x)
{
if (startPhase > endPhase)
{
mi.PhaseName = "New Moon";
break;
}
if (startPhase <= .25 && endPhase >= .25)
{
mi.PhaseName = "First Quarter";
break;
}
if (startPhase <= .5 && endPhase >= .5)
{
mi.PhaseName = "Full Moon";
break;
}
if (startPhase <= .75 && endPhase >= .75)
{
mi.PhaseName = "Last Quarter";
break;
}
if (startPhase > 0 && startPhase < .25 && endPhase > 0 && endPhase < .25)
{
mi.PhaseName = "Waxing Crescent";
break;
}
if (startPhase > .25 && startPhase < .5 && endPhase > .25 && endPhase < .5)
{
mi.PhaseName = "Waxing Gibbous";
break;
}
if (startPhase > .5 && startPhase < .75 && endPhase > .5 && endPhase < .75)
{
mi.PhaseName = "Waning Gibbous";
break;
}
if (startPhase > .75 && startPhase < 1 && endPhase > .75 && endPhase < 1)
{
mi.PhaseName = "Waning Crescent";
break;
}
}
}
if (date.Day == moonDate)
{
c.AstrologicalSigns.MoonName = moonName;
}
else
{
c.AstrologicalSigns.MoonName = "";
}
CalculateLunarEclipse(date, lat, lng, c);
}