public void calculateCoordinatesMethodC(GPGregorianTime vct, double DayHours)
{
double DG = GPMath.pi / 180;
double RAD = 180 / GPMath.pi;
// mean ecliptic longitude of the sun
double mel = SunGetMeanLong(vct.getYear(), vct.getMonth(), vct.getDay()) + (360 / 365.25) * DayHours / 360.0;
// ecliptic longitude of perigee
double elp = SunGetPerigee(vct.getYear(), vct.getMonth(), vct.getDay());
// mean anomaly of the sun
double M = mel - elp;
// equation of center
double C = 1.9148 * GPMath.sinDeg(M)
+ 0.02 * GPMath.sinDeg(2 * M)
+ 0.0003 * GPMath.sinDeg(3 * M);
// ecliptic longitude of the sun
double els = 0;
eclipticalLongitude = els = mel + C;
// declination of the sun
declination = GPMath.arcsinDeg(0.397948 * GPMath.sinDeg(eclipticalLongitude));
// right ascension of the sun
rightAscession = els - RAD * Math.Atan2(Math.Sin(2 * els * DG), 23.2377 + Math.Cos(2 * DG * els));
// equation of time
equationOfTime = rightAscession - mel;
//equationOfTime = GPAstroEngine.getEquationOfTime(julianDay, right_asc_deg);
//Debugger.Log(0,"", String.Format("{1}: EoTdiff = {0}\n", vct.getShortDateString(), equationOfTime - (right_asc_deg - mel)));
}
/// <summary>
/// Based on Chapter 39, Meeus and Chapter 10
/// </summary>
/// <param name="obs"></param>
public void makeTopocentric(GPObserver obs)
{
double u, h, delta_alpha;
double rho_sin, rho_cos;
const double b_a = 0.99664719;
// geocentric position of observer on the earth surface
// 10.1 - 10.3
u = GPMath.arctanDeg(b_a * b_a * GPMath.tanDeg(obs.GetLatitudeNorthPositive()));
rho_sin = b_a * GPMath.sinDeg(u) + obs.GetAltitude() / 6378140.0 * GPMath.sinDeg(obs.GetLatitudeNorthPositive());
rho_cos = GPMath.cosDeg(u) + obs.GetAltitude() / 6378140.0 * GPMath.cosDeg(obs.GetLatitudeNorthPositive());
// equatorial horizontal paralax
// 39.1
this.parallax = GPMath.arcsinDeg(GPMath.sinDeg(8.794 / 3600) / (this.distanceFromEarth / GPAstroEngine.AU));
// geocentric hour angle of the body
h = apparent_sidereal_time - obs.GetLongitudeWestPositive() - right_ascession;
// 39.2
delta_alpha = GPMath.arctanDeg(
(-rho_cos * GPMath.sinDeg(this.parallax) * GPMath.sinDeg(h)) /
(GPMath.cosDeg(this.declination) - rho_cos * GPMath.sinDeg(this.parallax) * GPMath.cosDeg(h)));
this.right_ascession += delta_alpha;
this.declination = GPMath.arctanDeg(
((GPMath.sinDeg(this.declination) - rho_sin * GPMath.sinDeg(this.parallax)) * GPMath.cosDeg(delta_alpha)) /
(GPMath.cosDeg(this.declination) - rho_cos * GPMath.sinDeg(this.parallax) * GPMath.cosDeg(h)));
}
public static void calc_geocentric(ref double longitude, ref double latitude, ref double rektaszension, ref double declination, double date)
{
//var
double epsilon; //: extended;
double delta_phi; //: extended;
double alpha, delta; //: extended;
calc_epsilon_phi(date, out delta_phi, out epsilon);
longitude = GPMath.putIn360(longitude + delta_phi);
alpha = GPMath.arctan2Deg(GPMath.sinDeg(longitude) * GPMath.cosDeg(epsilon) - GPMath.tanDeg(latitude) * GPMath.sinDeg(epsilon), GPMath.cosDeg(longitude));
delta = GPMath.arcsinDeg(GPMath.sinDeg(latitude) * GPMath.cosDeg(epsilon) + GPMath.cosDeg(latitude) * GPMath.sinDeg(epsilon) * GPMath.sinDeg(longitude));
rektaszension = alpha;
declination = delta;
double xg, yg, zg;
xg = GPMath.cosDeg(longitude) * GPMath.cosDeg(latitude);
yg = GPMath.sinDeg(longitude) * GPMath.cosDeg(latitude);
zg = GPMath.sinDeg(latitude);
alpha = GPMath.arctan2Deg(yg * GPMath.cosDeg(epsilon) - zg * GPMath.sinDeg(epsilon), GPMath.cosDeg(longitude) * GPMath.cosDeg(latitude));
}
public void calculateCoordinatesMethodM(double julian)
{
double DG = GPMath.rads;
double RAD = 180 / GPMath.pi;
double t = (julian - 2451545.0) / 36525;
double t2 = t * t;
double t3 = t2 * t;
double t4 = t2 * t2;
// mean ecliptic longitude of the sun
double L0 = 280.4664567 + 36000.76982779 * t + 0.0003032028 * t2 + t3 / 49931000;
// mean anomaly of the sun
double M = 357.5291 + 35999.05030 * t - 0.0001559 * t2 - 0.00000048 * t3;
L0 = GPMath.putIn360(L0);
M = GPMath.putIn360(M);
sunMeanAnomaly = M;
double C = (1.9146 - 0.004817 * t - 0.000014 * t2) * GPMath.sinDeg(M)
+ (0.019993 - 0.000101 * t) * GPMath.sinDeg(2 * M)
+ 0.00029 * GPMath.sinDeg(3 * M);
sunEquationCenter = C;
// ecliptic longitude of the sun
//double els = 0;
eclipticalLongitude = GPMath.putIn360(L0 + C);
double e = 0.016708617 - 0.000042037 * t - 0.0000001236 * t2;
double trueAnomaly = M + C;
// double epsilon;
// double deltaPhi;
// GPAstroEngine.calc_epsilon_phi(julianDay, out deltaPhi, out epsilon);
// = 23.4391 - 0.013 * t - t2/6101694;
double omega = 125.04 - 1934.136 * t;
double lambda = eclipticalLongitude - 0.00569 - 0.00478 * GPMath.sinDeg(omega);
double epsilon0 = 23.4392911 - 0.01300416 * t - 1.638e-7 * t2;
double epsilon1 = epsilon0 + 0.00256 * GPMath.cosDeg(omega);
// right ascension of the sun
this.rightAscession = RAD * Math.Atan2(GPMath.cosDeg(epsilon1) * GPMath.sinDeg(lambda), GPMath.cosDeg(lambda));
this.rightAscession = GPMath.putIn360(rightAscession);
// declination of the sun
this.declination = GPMath.arcsinDeg(GPMath.sinDeg(epsilon1) * GPMath.sinDeg(lambda));
// equation of time
equationOfTime = GPAstroEngine.getEquationOfTime(julian, this.rightAscession);
}
private void calculateRiseSetMethodM(double D, GPLocationProvider ed)
{
GPLocation obs = ed.getLocation(D);
double a1, a2, a3;
double d1, d2, d3;
double siderealTime = GPAstroEngine.GetSiderealTime(D);
double h0 = -0.833333;
calculateCoordinatesMethodM(D - 1);
a1 = rightAscession;
d1 = declination;
calculateCoordinatesMethodM(D);
a2 = rightAscession;
d2 = declination;
calculateCoordinatesMethodM(D + 1);
a3 = rightAscession;
d3 = declination;
double longitude = -ed.GetLongitudeEastPositive();
double latitude = ed.GetLatitudeNorthPositive();
double cosH0 = (GPMath.sinDeg(h0) - GPMath.sinDeg(latitude) * GPMath.sinDeg(d2))
/ (GPMath.cosDeg(latitude) * GPMath.cosDeg(d2));
double H0 = GPMath.arccosDeg(cosH0);
H0 = GPMath.putIn180(H0);
double m0 = (a2 + longitude - siderealTime) / 360;
double m1 = m0 - H0 / 360;
double m2 = m0 + H0 / 360;
double deltaM = 0;
deltaM = getCorrection(D, a1, a2, a3, d1, d2, d3, siderealTime, h0, longitude, latitude, m0, true);
m0 += deltaM;
deltaM = getCorrection(D, a1, a2, a3, d1, d2, d3, siderealTime, h0, longitude, latitude, m1, false);
m1 += deltaM;
deltaM = getCorrection(D, a1, a2, a3, d1, d2, d3, siderealTime, h0, longitude, latitude, m2, false);
m2 += deltaM;
julianDayRise = julianDay + m1;
julianDayNoon = julianDay + m0;
julianDaySet = julianDay + m2;
sunrise_deg = GPMath.putIn360(m1 * 360);
noon_deg = GPMath.putIn360(m0 * 360);
sunset_deg = GPMath.putIn360(m2 * 360);
}
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);
}
