public static EPD Calculate(double JD, EO @object)
{
//What will the the return value
EPD details = new EPD();
double JD0 = JD;
double L0 = 0;
double B0 = 0;
double R0 = 0;
double cosB0 = 0;
if (@object != EO.SUN)
{
L0 = CAAEarth.EclipticLongitude(JD0);
B0 = CAAEarth.EclipticLatitude(JD0);
R0 = CAAEarth.RadiusVector(JD0);
L0 = CT.D2R(L0);
B0 = CT.D2R(B0);
cosB0 = Math.Cos(B0);
}
//Calculate the initial values
double L = 0;
double B = 0;
double R = 0;
double Lrad;
double Brad;
double cosB;
double cosL;
double x;
double y;
double z;
bool bRecalc = true;
bool bFirstRecalc = true;
double LPrevious = 0;
double BPrevious = 0;
double RPrevious = 0;
while (bRecalc)
{
switch (@object)
{
case EO.SUN:
{
L = CAASun.GeometricEclipticLongitude(JD0);
B = CAASun.GeometricEclipticLatitude(JD0);
R = CAAEarth.RadiusVector(JD0);
break;
}
case EO.MERCURY:
{
L = CAAMercury.EclipticLongitude(JD0);
B = CAAMercury.EclipticLatitude(JD0);
R = CAAMercury.RadiusVector(JD0);
break;
}
case EO.VENUS:
{
L = CAAVenus.EclipticLongitude(JD0);
B = CAAVenus.EclipticLatitude(JD0);
R = CAAVenus.RadiusVector(JD0);
break;
}
case EO.MARS:
{
L = CAAMars.EclipticLongitude(JD0);
B = CAAMars.EclipticLatitude(JD0);
R = CAAMars.RadiusVector(JD0);
break;
}
case EO.JUPITER:
{
L = CAAJupiter.EclipticLongitude(JD0);
B = CAAJupiter.EclipticLatitude(JD0);
R = CAAJupiter.RadiusVector(JD0);
break;
}
case EO.SATURN:
{
L = CAASaturn.EclipticLongitude(JD0);
B = CAASaturn.EclipticLatitude(JD0);
R = CAASaturn.RadiusVector(JD0);
break;
}
case EO.URANUS:
{
L = CAAUranus.EclipticLongitude(JD0);
B = CAAUranus.EclipticLatitude(JD0);
R = CAAUranus.RadiusVector(JD0);
break;
}
case EO.NEPTUNE:
{
L = CAANeptune.EclipticLongitude(JD0);
B = CAANeptune.EclipticLatitude(JD0);
R = CAANeptune.RadiusVector(JD0);
break;
}
case EO.PLUTO:
{
L = CAAPluto.EclipticLongitude(JD0);
B = CAAPluto.EclipticLatitude(JD0);
R = CAAPluto.RadiusVector(JD0);
break;
}
default:
{
Debug.Assert(false);
break;
}
}
if (!bFirstRecalc)
{
bRecalc = ((Math.Abs(L - LPrevious) > 0.00001) || (Math.Abs(B - BPrevious) > 0.00001) || (Math.Abs(R - RPrevious) > 0.000001));
LPrevious = L;
BPrevious = B;
RPrevious = R;
}
else
{
bFirstRecalc = false;
}
//Calculate the new value
if (bRecalc)
{
double distance = 0;
if (@object != EO.SUN)
{
Lrad = CT.D2R(L);
Brad = CT.D2R(B);
cosB = Math.Cos(Brad);
cosL = Math.Cos(Lrad);
x = R * cosB * cosL - R0 * cosB0 * Math.Cos(L0);
y = R * cosB * Math.Sin(Lrad) - R0 * cosB0 * Math.Sin(L0);
z = R * Math.Sin(Brad) - R0 * Math.Sin(B0);
distance = Math.Sqrt(x * x + y * y + z * z);
}
else
{
distance = R; //Distance to the sun from the earth is in fact the radius vector
}
//Prepare for the next loop around
JD0 = JD - ELL.DistanceToLightTime(distance);
}
}
Lrad = CT.D2R(L);
Brad = CT.D2R(B);
cosB = Math.Cos(Brad);
cosL = Math.Cos(Lrad);
x = R * cosB * cosL - R0 * cosB0 * Math.Cos(L0);
y = R * cosB * Math.Sin(Lrad) - R0 * cosB0 * Math.Sin(L0);
z = R * Math.Sin(Brad) - R0 * Math.Sin(B0);
double x2 = x * x;
double y2 = y * y;
details.ApparentGeocentricLatitude = CT.R2D(Math.Atan2(z, Math.Sqrt(x2 + y2)));
details.ApparentGeocentricDistance = Math.Sqrt(x2 + y2 + z * z);
details.ApparentGeocentricLongitude = CT.M360(CT.R2D(Math.Atan2(y, x)));
details.ApparentLightTime = ELL.DistanceToLightTime(details.ApparentGeocentricDistance);
//Adjust for Aberration
COR Aberration = ABR.EclipticAberration(details.ApparentGeocentricLongitude, details.ApparentGeocentricLatitude, JD);
details.ApparentGeocentricLongitude += Aberration.X;
details.ApparentGeocentricLatitude += Aberration.Y;
//convert to the FK5 system
double DeltaLong = CAAFK5.CorrectionInLongitude(details.ApparentGeocentricLongitude, details.ApparentGeocentricLatitude, JD);
details.ApparentGeocentricLatitude += CAAFK5.CorrectionInLatitude(details.ApparentGeocentricLongitude, JD);
details.ApparentGeocentricLongitude += DeltaLong;
//Correct for nutation
double NutationInLongitude = CAANutation.NutationInLongitude(JD);
double Epsilon = CAANutation.TrueObliquityOfEcliptic(JD);
details.ApparentGeocentricLongitude += CT.DMS2D(0, 0, NutationInLongitude);
//Convert to RA and Dec
COR ApparentEqu = CT.Ec2Eq(details.ApparentGeocentricLongitude, details.ApparentGeocentricLatitude, Epsilon);
details.ApparentGeocentricRA = ApparentEqu.X;
details.ApparentGeocentricDeclination = ApparentEqu.Y;
return(details);
}
//Static methods
//////////////////////////////// Implementation ///////////////////////////////
public static CAAPhysicalMarsDetails Calculate(double JD)
{
//What will be the return value
CAAPhysicalMarsDetails details = new CAAPhysicalMarsDetails();
//Step 1
double T = (JD - 2451545) / 36525;
double Lambda0 = 352.9065 + 1.17330 * T;
double Lambda0rad = CT.D2R(Lambda0);
double Beta0 = 63.2818 - 0.00394 * T;
double Beta0rad = CT.D2R(Beta0);
//Step 2
double l0 = CAAEarth.EclipticLongitude(JD);
double l0rad = CT.D2R(l0);
double b0 = CAAEarth.EclipticLatitude(JD);
double b0rad = CT.D2R(b0);
double R = CAAEarth.RadiusVector(JD);
double PreviousLightTravelTime = 0;
double LightTravelTime = 0;
double x = 0;
double y = 0;
double z = 0;
bool bIterate = true;
double DELTA = 0;
double l = 0;
double lrad = 0;
double b = 0;
double brad = 0;
double r = 0;
while (bIterate)
{
double JD2 = JD - LightTravelTime;
//Step 3
l = CAAMars.EclipticLongitude(JD2);
lrad = CT.D2R(l);
b = CAAMars.EclipticLatitude(JD2);
brad = CT.D2R(b);
r = CAAMars.RadiusVector(JD2);
//Step 4
x = r * Math.Cos(brad) * Math.Cos(lrad) - R * Math.Cos(l0rad);
y = r * Math.Cos(brad) * Math.Sin(lrad) - R * Math.Sin(l0rad);
z = r * Math.Sin(brad) - R * Math.Sin(b0rad);
DELTA = Math.Sqrt(x * x + y * y + z * z);
LightTravelTime = ELL.DistanceToLightTime(DELTA);
//Prepare for the next loop around
bIterate = (Math.Abs(LightTravelTime - PreviousLightTravelTime) > 2E-6); //2E-6 correponds to 0.17 of a second
if (bIterate)
{
PreviousLightTravelTime = LightTravelTime;
}
}
//Step 5
double lambdarad = Math.Atan2(y, x);
double lambda = CT.R2D(lambdarad);
double betarad = Math.Atan2(z, Math.Sqrt(x * x + y * y));
double beta = CT.R2D(betarad);
//Step 6
details.DE = CT.R2D(Math.Asin(-Math.Sin(Beta0rad) * Math.Sin(betarad) - Math.Cos(Beta0rad) * Math.Cos(betarad) * Math.Cos(Lambda0rad - lambdarad)));
//Step 7
double N = 49.5581 + 0.7721 * T;
double Nrad = CT.D2R(N);
double ldash = l - 0.00697 / r;
double ldashrad = CT.D2R(ldash);
double bdash = b - 0.000225 * (Math.Cos(lrad - Nrad) / r);
double bdashrad = CT.D2R(bdash);
//Step 8
details.DS = CT.R2D(Math.Asin(-Math.Sin(Beta0rad) * Math.Sin(bdashrad) - Math.Cos(Beta0rad) * Math.Cos(bdashrad) * Math.Cos(Lambda0rad - ldashrad)));
//Step 9
double W = CT.M360(11.504 + 350.89200025 * (JD - LightTravelTime - 2433282.5));
//Step 10
double e0 = CAANutation.MeanObliquityOfEcliptic(JD);
double e0rad = CT.D2R(e0);
COR PoleEquatorial = CT.Ec2Eq(Lambda0, Beta0, e0);
double alpha0rad = CT.H2R(PoleEquatorial.X);
double delta0rad = CT.D2R(PoleEquatorial.Y);
//Step 11
double u = y * Math.Cos(e0rad) - z * Math.Sin(e0rad);
double v = y * Math.Sin(e0rad) + z * Math.Cos(e0rad);
double alpharad = Math.Atan2(u, x);
double alpha = CT.R2H(alpharad);
double deltarad = Math.Atan2(v, Math.Sqrt(x * x + u * u));
double delta = CT.R2D(deltarad);
double xi = Math.Atan2(Math.Sin(delta0rad) * Math.Cos(deltarad) * Math.Cos(alpha0rad - alpharad) - Math.Sin(deltarad) * Math.Cos(delta0rad), Math.Cos(deltarad) * Math.Sin(alpha0rad - alpharad));
//Step 12
details.w = CT.M360(W - CT.R2D(xi));
//Step 13
double NutationInLongitude = CAANutation.NutationInLongitude(JD);
double NutationInObliquity = CAANutation.NutationInObliquity(JD);
//Step 14
lambda += 0.005693 * Math.Cos(l0rad - lambdarad) / Math.Cos(betarad);
beta += 0.005693 * Math.Sin(l0rad - lambdarad) * Math.Sin(betarad);
//Step 15
Lambda0 += NutationInLongitude / 3600;
Lambda0rad = CT.D2R(Lambda0);
lambda += NutationInLongitude / 3600;
lambdarad = CT.D2R(lambda);
e0 += NutationInObliquity / 3600;
e0rad = CT.D2R(e0rad);
//Step 16
COR ApparentPoleEquatorial = CT.Ec2Eq(Lambda0, Beta0, e0);
double alpha0dash = CT.H2R(ApparentPoleEquatorial.X);
double delta0dash = CT.D2R(ApparentPoleEquatorial.Y);
COR ApparentMars = CT.Ec2Eq(lambda, beta, e0);
double alphadash = CT.H2R(ApparentMars.X);
double deltadash = CT.D2R(ApparentMars.Y);
//Step 17
details.P = CT.M360(CT.R2D(Math.Atan2(Math.Cos(delta0dash) * Math.Sin(alpha0dash - alphadash), Math.Sin(delta0dash) * Math.Cos(deltadash) - Math.Cos(delta0dash) * Math.Sin(deltadash) * Math.Cos(alpha0dash - alphadash))));
//Step 18
double SunLambda = CAASun.GeometricEclipticLongitude(JD);
double SunBeta = CAASun.GeometricEclipticLatitude(JD);
COR SunEquatorial = CT.Ec2Eq(SunLambda, SunBeta, e0);
details.X = MIFR.PositionAngle(SunEquatorial.X, SunEquatorial.Y, alpha, delta);
//Step 19
details.d = 9.36 / DELTA;
details.k = IFR.IlluminatedFraction2(r, R, DELTA);
details.q = (1 - details.k) * details.d;
return(details);
}
