public static RiseSetDetails GetRiseTrinsitSet(double jd, double lat, double lng, double ra1, double dec1, double ra2, double dec2, double ra3, double dec3, int type)
{
double alt = -0.5667;
switch (type)
{
case 0: // Planet or star
alt = -0.5667;
break;
case 1: // sun
alt = -0.8333;
break;
case 2:
alt = 0.125;
break;
}
CAARiseTransitSetDetails RiseTransitSetTime = CAARiseTransitSet.Rise(jd, ra1, dec1, ra2, dec2, ra3, dec3, lng, lat, alt);
bool neverRises = false;
if (!RiseTransitSetTime.bValid)
{
neverRises = Util.Sign(lat) != Util.Sign(dec2);
}
return(new RiseSetDetails(RiseTransitSetTime.bValid, RiseTransitSetTime.Rise, RiseTransitSetTime.Transit, RiseTransitSetTime.Set, neverRises));
}
//Static methods
///////////////////////////// Implementation //////////////////////////////////
public static CAARiseTransitSetDetails Rise(double JD, double Alpha1, double Delta1, double Alpha2, double Delta2, double Alpha3, double Delta3, double Longitude, double Latitude, double h0)
{
//What will be the return value
CAARiseTransitSetDetails details = new CAARiseTransitSetDetails();
details.bValid = false;
//Calculate the sidereal time
double theta0 = CAASidereal.ApparentGreenwichSiderealTime(JD);
theta0 *= 15; //Express it as degrees
//Calculate deltat
double deltaT = CAADynamicalTime.DeltaT(JD);
//Convert values to radians
double Delta2Rad = CAACoordinateTransformation.DegreesToRadians(Delta2);
double LatitudeRad = CAACoordinateTransformation.DegreesToRadians(Latitude);
//Convert the standard latitude to radians
double h0Rad = CAACoordinateTransformation.DegreesToRadians(h0);
double cosH0 = (Math.Sin(h0Rad) - Math.Sin(LatitudeRad)*Math.Sin(Delta2Rad)) / (Math.Cos(LatitudeRad) * Math.Cos(Delta2Rad));
//Check that the object actually rises
if ((cosH0 > 1) || (cosH0 < -1))
return details;
double H0 = Math.Acos(cosH0);
H0 = CAACoordinateTransformation.RadiansToDegrees(H0);
double M0 = (Alpha2 *15 + Longitude - theta0) / 360;
double M1 = M0 - H0/360;
double M2 = M0 + H0/360;
if (M0 > 1)
M0 -= 1;
else if (M0 < 0)
M0 += 1;
if (M1 > 1)
M1 -= 1;
else if (M1 < 0)
M1 += 1;
if (M2 > 1)
M2 -= 1;
else if (M2 < 0)
M2 += 1;
for (int i =0; i<2; i++)
{
//Calculate the details of rising
double theta1 = theta0 + 360.985647 *M1;
theta1 = CAACoordinateTransformation.MapTo0To360Range(theta1);
double n = M1 + deltaT/86400;
double Alpha = CAAInterpolate.Interpolate(n, Alpha1, Alpha2, Alpha3);
double Delta = CAAInterpolate.Interpolate(n, Delta1, Delta2, Delta3);
double H = theta1 - Longitude - Alpha *15;
CAA2DCoordinate Horizontal = CAACoordinateTransformation.Equatorial2Horizontal(H/15, Delta, Latitude);
double DeltaM = (Horizontal.Y - h0) / (360 *Math.Cos(CAACoordinateTransformation.DegreesToRadians(Delta))*Math.Cos(LatitudeRad)*Math.Sin(CAACoordinateTransformation.DegreesToRadians(H)));
M1 += DeltaM;
//Calculate the details of transit
theta1 = theta0 + 360.985647 *M0;
theta1 = CAACoordinateTransformation.MapTo0To360Range(theta1);
n = M0 + deltaT/86400;
Alpha = CAAInterpolate.Interpolate(n, Alpha1, Alpha2, Alpha3);
H = theta1 - Longitude - Alpha *15;
if (H < -180)
{
H+=360;
}
DeltaM = -H / 360;
M0 += DeltaM;
//Calculate the details of setting
theta1 = theta0 + 360.985647 *M2;
theta1 = CAACoordinateTransformation.MapTo0To360Range(theta1);
n = M2 + deltaT/86400;
Alpha = CAAInterpolate.Interpolate(n, Alpha1, Alpha2, Alpha3);
Delta = CAAInterpolate.Interpolate(n, Delta1, Delta2, Delta3);
H = theta1 - Longitude - Alpha *15;
Horizontal = CAACoordinateTransformation.Equatorial2Horizontal(H/15, Delta, Latitude);
DeltaM = (Horizontal.Y - h0) / (360 *Math.Cos(CAACoordinateTransformation.DegreesToRadians(Delta))*Math.Cos(LatitudeRad)*Math.Sin(CAACoordinateTransformation.DegreesToRadians(H)));
M2 += DeltaM;
}
//Finally before we exit, convert to hours
details.bValid = true;
details.Rise = M1 * 24;
details.Set = M2 * 24;
details.Transit = M0 * 24;
return details;
}
//Static methods
///////////////////////////// Implementation //////////////////////////////////
public static CAARiseTransitSetDetails Rise(double JD, double Alpha1, double Delta1, double Alpha2, double Delta2, double Alpha3, double Delta3, double Longitude, double Latitude, double h0)
{
//What will be the return value
CAARiseTransitSetDetails details = new CAARiseTransitSetDetails();
details.bValid = false;
//Calculate the sidereal time
double theta0 = CAASidereal.ApparentGreenwichSiderealTime(JD);
theta0 *= 15; //Express it as degrees
//Calculate deltat
double deltaT = DYT.DeltaT(JD);
//Convert values to radians
double Delta2Rad = CT.D2R(Delta2);
double LatitudeRad = CT.D2R(Latitude);
//Convert the standard latitude to radians
double h0Rad = CT.D2R(h0);
double cosH0 = (Math.Sin(h0Rad) - Math.Sin(LatitudeRad) * Math.Sin(Delta2Rad)) / (Math.Cos(LatitudeRad) * Math.Cos(Delta2Rad));
//Check that the object actually rises
if ((cosH0 > 1) || (cosH0 < -1))
{
return(details);
}
double H0 = Math.Acos(cosH0);
H0 = CT.R2D(H0);
double M0 = (Alpha2 * 15 + Longitude - theta0) / 360;
double M1 = M0 - H0 / 360;
double M2 = M0 + H0 / 360;
if (M0 > 1)
{
M0 -= 1;
}
else if (M0 < 0)
{
M0 += 1;
}
if (M1 > 1)
{
M1 -= 1;
}
else if (M1 < 0)
{
M1 += 1;
}
if (M2 > 1)
{
M2 -= 1;
}
else if (M2 < 0)
{
M2 += 1;
}
for (int i = 0; i < 2; i++)
{
//Calculate the details of rising
double theta1 = theta0 + 360.985647 * M1;
theta1 = CT.M360(theta1);
double n = M1 + deltaT / 86400;
double Alpha = INTP.Interpolate(n, Alpha1, Alpha2, Alpha3);
double Delta = INTP.Interpolate(n, Delta1, Delta2, Delta3);
double H = theta1 - Longitude - Alpha * 15;
COR Horizontal = CT.Eq2H(H / 15, Delta, Latitude);
double DeltaM = (Horizontal.Y - h0) / (360 * Math.Cos(CT.D2R(Delta)) * Math.Cos(LatitudeRad) * Math.Sin(CT.D2R(H)));
M1 += DeltaM;
//Calculate the details of transit
theta1 = theta0 + 360.985647 * M0;
theta1 = CT.M360(theta1);
n = M0 + deltaT / 86400;
Alpha = INTP.Interpolate(n, Alpha1, Alpha2, Alpha3);
H = theta1 - Longitude - Alpha * 15;
if (H < -180)
{
H += 360;
}
DeltaM = -H / 360;
M0 += DeltaM;
//Calculate the details of setting
theta1 = theta0 + 360.985647 * M2;
theta1 = CT.M360(theta1);
n = M2 + deltaT / 86400;
Alpha = INTP.Interpolate(n, Alpha1, Alpha2, Alpha3);
Delta = INTP.Interpolate(n, Delta1, Delta2, Delta3);
H = theta1 - Longitude - Alpha * 15;
Horizontal = CT.Eq2H(H / 15, Delta, Latitude);
DeltaM = (Horizontal.Y - h0) / (360 * Math.Cos(CT.D2R(Delta)) * Math.Cos(LatitudeRad) * Math.Sin(CT.D2R(H)));
M2 += DeltaM;
}
//Finally before we exit, convert to hours
details.bValid = true;
details.Rise = M1 * 24;
details.Set = M2 * 24;
details.Transit = M0 * 24;
return(details);
}
