//Static methods
///////////////////////// Implementation //////////////////////////////////////
public static double Calculate(double JD)
{
double rho = (JD - 2451545) / 365250;
double rhosquared = rho * rho;
double rhocubed = rhosquared * rho;
double rho4 = rhocubed * rho;
double rho5 = rho4 * rho;
//Calculate the Suns mean longitude
double L0 = CAACoordinateTransformation.MapTo0To360Range(280.4664567 + 360007.6982779 * rho + 0.03032028 * rhosquared + rhocubed / 49931 - rho4 / 15300 - rho5 / 2000000);
//Calculate the Suns apparent right ascension
double SunLong = CAASun.ApparentEclipticLongitude(JD);
double SunLat = CAASun.ApparentEclipticLatitude(JD);
double epsilon = CAANutation.TrueObliquityOfEcliptic(JD);
CAA2DCoordinate Equatorial = CAACoordinateTransformation.Ecliptic2Equatorial(SunLong, SunLat, epsilon);
epsilon = CAACoordinateTransformation.DegreesToRadians(epsilon);
double E = L0 - 0.0057183 - Equatorial.X * 15 + CAACoordinateTransformation.DMSToDegrees(0, 0, CAANutation.NutationInLongitude(JD)) * Math.Cos(epsilon);
if (E > 180)
{
E = -(360 - E);
}
E *= 4; //Convert to minutes of time
return(E);
}
protected static CAAPhysicalMoonDetails CalculateHelper(double JD, ref double Lambda, ref double Beta, ref double epsilon, ref CAA2DCoordinate Equatorial)
{
//What will be the return value
CAAPhysicalMoonDetails details = new CAAPhysicalMoonDetails();
//Calculate the initial quantities
Lambda = CAAMoon.EclipticLongitude(JD);
Beta = CAAMoon.EclipticLatitude(JD);
//Calculate the optical libration
double omega = 0;
double DeltaU = 0;
double sigma = 0;
double I = 0;
double rho = 0;
CalculateOpticalLibration(JD, Lambda, Beta, ref details.ldash, ref details.bdash, ref details.ldash2, ref details.bdash2, ref epsilon, ref omega, ref DeltaU, ref sigma, ref I, ref rho);
double epsilonrad = CAACoordinateTransformation.DegreesToRadians(epsilon);
//Calculate the total libration
details.l = details.ldash + details.ldash2;
details.b = details.bdash + details.bdash2;
double b = CAACoordinateTransformation.DegreesToRadians(details.b);
//Calculate the position angle
double V = omega + DeltaU + CAACoordinateTransformation.DegreesToRadians(sigma) / Math.Sin(I);
double I_rho = I + CAACoordinateTransformation.DegreesToRadians(rho);
double X = Math.Sin(I_rho) * Math.Sin(V);
double Y = Math.Sin(I_rho) * Math.Cos(V) * Math.Cos(epsilonrad) - Math.Cos(I_rho) * Math.Sin(epsilonrad);
double w = Math.Atan2(X, Y);
Equatorial = CAACoordinateTransformation.Ecliptic2Equatorial(Lambda, Beta, epsilon);
double Alpha = CAACoordinateTransformation.HoursToRadians(Equatorial.X);
details.P = CAACoordinateTransformation.RadiansToDegrees(Math.Asin(Math.Sqrt(X * X + Y * Y) * Math.Cos(Alpha - w) / (Math.Cos(b))));
return(details);
}
//Static methods
//////////////////////////////// Implementation ///////////////////////////////
public static CAASaturnRingDetails Calculate(double JD)
{
//What will be the return value
CAASaturnRingDetails details = new CAASaturnRingDetails();
double T = (JD - 2451545) / 36525;
double T2 = T * T;
//Step 1. Calculate the inclination of the plane of the ring and the longitude of the ascending node referred to the ecliptic and mean equinox of the date
double i = 28.075216 - 0.012998 * T + 0.000004 * T2;
double irad = CAACoordinateTransformation.DegreesToRadians(i);
double omega = 169.508470 + 1.394681 * T + 0.000412 * T2;
double omegarad = CAACoordinateTransformation.DegreesToRadians(omega);
//Step 2. Calculate the heliocentric longitude, latitude and radius vector of the Earth in the FK5 system
double l0 = CAAEarth.EclipticLongitude(JD);
double b0 = CAAEarth.EclipticLatitude(JD);
l0 += CAAFK5.CorrectionInLongitude(l0, b0, JD);
double l0rad = CAACoordinateTransformation.DegreesToRadians(l0);
b0 += CAAFK5.CorrectionInLatitude(l0, JD);
double b0rad = CAACoordinateTransformation.DegreesToRadians(b0);
double R = CAAEarth.RadiusVector(JD);
//Step 3. Calculate the corresponding coordinates l,b,r for Saturn but for the instance t-lightraveltime
double DELTA = 9;
double PreviousEarthLightTravelTime = 0;
double EarthLightTravelTime = CAAElliptical.DistanceToLightTime(DELTA);
double JD1 = JD - EarthLightTravelTime;
bool bIterate = true;
double x = 0;
double y = 0;
double z = 0;
double l = 0;
double b = 0;
double r = 0;
while (bIterate)
{
//Calculate the position of Saturn
l = CAASaturn.EclipticLongitude(JD1);
b = CAASaturn.EclipticLatitude(JD1);
l += CAAFK5.CorrectionInLongitude(l, b, JD1);
b += CAAFK5.CorrectionInLatitude(l, JD1);
double lrad = CAACoordinateTransformation.DegreesToRadians(l);
double brad = CAACoordinateTransformation.DegreesToRadians(b);
r = CAASaturn.RadiusVector(JD1);
//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);
EarthLightTravelTime = CAAElliptical.DistanceToLightTime(DELTA);
//Prepare for the next loop around
bIterate = (Math.Abs(EarthLightTravelTime - PreviousEarthLightTravelTime) > 2E-6); //2E-6 corresponds to 0.17 of a second
if (bIterate)
{
JD1 = JD - EarthLightTravelTime;
PreviousEarthLightTravelTime = EarthLightTravelTime;
}
}
//Step 5. Calculate Saturn's geocentric Longitude and Latitude
double lambda = Math.Atan2(y, x);
double beta = Math.Atan2(z, Math.Sqrt(x * x + y * y));
//Step 6. Calculate B, a and b
details.B = Math.Asin(Math.Sin(irad) * Math.Cos(beta) * Math.Sin(lambda - omegarad) - Math.Cos(irad) * Math.Sin(beta));
details.a = 375.35 / DELTA;
details.b = details.a * Math.Sin(Math.Abs(details.B));
details.B = CAACoordinateTransformation.RadiansToDegrees(details.B);
//Step 7. Calculate the longitude of the ascending node of Saturn's orbit
double N = 113.6655 + 0.8771 * T;
double Nrad = CAACoordinateTransformation.DegreesToRadians(N);
double ldash = l - 0.01759 / r;
double ldashrad = CAACoordinateTransformation.DegreesToRadians(ldash);
double bdash = b - 0.000764 * Math.Cos(ldashrad - Nrad) / r;
double bdashrad = CAACoordinateTransformation.DegreesToRadians(bdash);
//Step 8. Calculate Bdash
details.Bdash = CAACoordinateTransformation.RadiansToDegrees(Math.Asin(Math.Sin(irad) * Math.Cos(bdashrad) * Math.Sin(ldashrad - omegarad) - Math.Cos(irad) * Math.Sin(bdashrad)));
//Step 9. Calculate DeltaU
double U1 = Math.Atan2(Math.Sin(irad) * Math.Sin(bdashrad) + Math.Cos(irad) * Math.Cos(bdashrad) * Math.Sin(ldashrad - omegarad), Math.Cos(bdashrad) * Math.Cos(ldashrad - omegarad));
double U2 = Math.Atan2(Math.Sin(irad) * Math.Sin(beta) + Math.Cos(irad) * Math.Cos(beta) * Math.Sin(lambda - omegarad), Math.Cos(beta) * Math.Cos(lambda - omegarad));
details.DeltaU = CAACoordinateTransformation.RadiansToDegrees(Math.Abs(U1 - U2));
//Step 10. Calculate the Nutations
double Obliquity = CAANutation.TrueObliquityOfEcliptic(JD);
double NutationInLongitude = CAANutation.NutationInLongitude(JD);
//Step 11. Calculate the Ecliptical longitude and latitude of the northern pole of the ring plane
double lambda0 = omega - 90;
double beta0 = 90 - i;
//Step 12. Correct lambda and beta for the aberration of Saturn
lambda += CAACoordinateTransformation.DegreesToRadians(0.005693 * Math.Cos(l0rad - lambda) / Math.Cos(beta));
beta += CAACoordinateTransformation.DegreesToRadians(0.005693 * Math.Sin(l0rad - lambda) * Math.Sin(beta));
//Step 13. Add nutation in longitude to lambda0 and lambda
//double NLrad = CAACoordinateTransformation::DegreesToRadians(NutationInLongitude/3600);
lambda = CAACoordinateTransformation.RadiansToDegrees(lambda);
lambda += NutationInLongitude / 3600;
lambda = CAACoordinateTransformation.MapTo0To360Range(lambda);
lambda0 += NutationInLongitude / 3600;
lambda0 = CAACoordinateTransformation.MapTo0To360Range(lambda0);
//Step 14. Convert to equatorial coordinates
beta = CAACoordinateTransformation.RadiansToDegrees(beta);
CAA2DCoordinate GeocentricEclipticSaturn = CAACoordinateTransformation.Ecliptic2Equatorial(lambda, beta, Obliquity);
double alpha = CAACoordinateTransformation.HoursToRadians(GeocentricEclipticSaturn.X);
double delta = CAACoordinateTransformation.DegreesToRadians(GeocentricEclipticSaturn.Y);
CAA2DCoordinate GeocentricEclipticNorthPole = CAACoordinateTransformation.Ecliptic2Equatorial(lambda0, beta0, Obliquity);
double alpha0 = CAACoordinateTransformation.HoursToRadians(GeocentricEclipticNorthPole.X);
double delta0 = CAACoordinateTransformation.DegreesToRadians(GeocentricEclipticNorthPole.Y);
//Step 15. Calculate the Position angle
details.P = CAACoordinateTransformation.RadiansToDegrees(Math.Atan2(Math.Cos(delta0) * Math.Sin(alpha0 - alpha), Math.Sin(delta0) * Math.Cos(delta) - Math.Cos(delta0) * Math.Sin(delta) * Math.Cos(alpha0 - alpha)));
return(details);
}
public static CAAEllipticalPlanetaryDetails Calculate(double JD, EllipticalObject @object)
{
//What will the the return value
CAAEllipticalPlanetaryDetails details = new CAAEllipticalPlanetaryDetails();
double JD0 = JD;
double L0 = 0;
double B0 = 0;
double R0 = 0;
double cosB0 = 0;
if (@object != EllipticalObject.SUN)
{
L0 = CAAEarth.EclipticLongitude(JD0);
B0 = CAAEarth.EclipticLatitude(JD0);
R0 = CAAEarth.RadiusVector(JD0);
L0 = CAACoordinateTransformation.DegreesToRadians(L0);
B0 = CAACoordinateTransformation.DegreesToRadians(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 EllipticalObject.SUN:
{
L = CAASun.GeometricEclipticLongitude(JD0);
B = CAASun.GeometricEclipticLatitude(JD0);
R = CAAEarth.RadiusVector(JD0);
break;
}
case EllipticalObject.MERCURY:
{
L = CAAMercury.EclipticLongitude(JD0);
B = CAAMercury.EclipticLatitude(JD0);
R = CAAMercury.RadiusVector(JD0);
break;
}
case EllipticalObject.VENUS:
{
L = CAAVenus.EclipticLongitude(JD0);
B = CAAVenus.EclipticLatitude(JD0);
R = CAAVenus.RadiusVector(JD0);
break;
}
case EllipticalObject.MARS:
{
L = CAAMars.EclipticLongitude(JD0);
B = CAAMars.EclipticLatitude(JD0);
R = CAAMars.RadiusVector(JD0);
break;
}
case EllipticalObject.JUPITER:
{
L = CAAJupiter.EclipticLongitude(JD0);
B = CAAJupiter.EclipticLatitude(JD0);
R = CAAJupiter.RadiusVector(JD0);
break;
}
case EllipticalObject.SATURN:
{
L = CAASaturn.EclipticLongitude(JD0);
B = CAASaturn.EclipticLatitude(JD0);
R = CAASaturn.RadiusVector(JD0);
break;
}
case EllipticalObject.URANUS:
{
L = CAAUranus.EclipticLongitude(JD0);
B = CAAUranus.EclipticLatitude(JD0);
R = CAAUranus.RadiusVector(JD0);
break;
}
case EllipticalObject.NEPTUNE:
{
L = CAANeptune.EclipticLongitude(JD0);
B = CAANeptune.EclipticLatitude(JD0);
R = CAANeptune.RadiusVector(JD0);
break;
}
case EllipticalObject.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 != EllipticalObject.SUN)
{
Lrad = CAACoordinateTransformation.DegreesToRadians(L);
Brad = CAACoordinateTransformation.DegreesToRadians(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 - CAAElliptical.DistanceToLightTime(distance);
}
}
Lrad = CAACoordinateTransformation.DegreesToRadians(L);
Brad = CAACoordinateTransformation.DegreesToRadians(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 = CAACoordinateTransformation.RadiansToDegrees(Math.Atan2(z, Math.Sqrt(x2 + y2)));
details.ApparentGeocentricDistance = Math.Sqrt(x2 + y2 + z * z);
details.ApparentGeocentricLongitude = CAACoordinateTransformation.MapTo0To360Range(CAACoordinateTransformation.RadiansToDegrees(Math.Atan2(y, x)));
details.ApparentLightTime = CAAElliptical.DistanceToLightTime(details.ApparentGeocentricDistance);
//Adjust for Aberration
CAA2DCoordinate Aberration = CAAAberration.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 += CAACoordinateTransformation.DMSToDegrees(0, 0, NutationInLongitude);
//Convert to RA and Dec
CAA2DCoordinate ApparentEqu = CAACoordinateTransformation.Ecliptic2Equatorial(details.ApparentGeocentricLongitude, details.ApparentGeocentricLatitude, Epsilon);
details.ApparentGeocentricRA = ApparentEqu.X;
details.ApparentGeocentricDeclination = ApparentEqu.Y;
return(details);
}
public static AstroRaDec GetPlanet(double jDate, int planet, double locLat, double locLong, double locHeight)
{
locLong = -locLong;
if (planet < 9)
{
CAAEllipticalPlanetaryDetails Details = CAAElliptical.Calculate(jDate, (EllipticalObject)planet);
CAA2DCoordinate corrected = CAAParallax.Equatorial2Topocentric(Details.ApparentGeocentricRA, Details.ApparentGeocentricDeclination, Details.ApparentGeocentricDistance, locLong, locLat, locHeight, jDate);
return(new AstroRaDec(corrected.X, corrected.Y, Details.ApparentGeocentricDistance, false, false));
}
else if (planet == 9)
{
double lat = CAAMoon.EclipticLatitude(jDate);
double lng = CAAMoon.EclipticLongitude(jDate);
double dis = CAAMoon.RadiusVector(jDate) / 149598000;
double epsilon = CAANutation.TrueObliquityOfEcliptic(jDate);
CAA2DCoordinate d = CAACoordinateTransformation.Ecliptic2Equatorial(lng, lat, epsilon);
CAA2DCoordinate corrected = CAAParallax.Equatorial2Topocentric(d.X, d.Y, dis, locLong, locLat, locHeight, jDate);
return(new AstroRaDec(corrected.X, corrected.Y, dis, false, false));
}
else
{
if (jDate != jDateLast)
{
jupDetails = CAAElliptical.Calculate(jDate, (EllipticalObject)4);
jupPhisical = CAAPhysicalJupiter.Calculate(jDate);
CAA2DCoordinate corrected = CAAParallax.Equatorial2Topocentric(jupDetails.ApparentGeocentricRA, jupDetails.ApparentGeocentricDeclination, jupDetails.ApparentGeocentricDistance, locLong, locLat, locHeight, jDate);
jupDetails.ApparentGeocentricRA = corrected.X;
jupDetails.ApparentGeocentricDeclination = corrected.Y;
galDetails = CAAGalileanMoons.Calculate(jDate);
jDateLast = jDate;
}
double jupiterDiameter = 0.000954501;
double scale = (Math.Atan(.5 * (jupiterDiameter / jupDetails.ApparentGeocentricDistance))) / 3.1415927 * 180;
double raScale = (scale / Math.Cos(jupDetails.ApparentGeocentricDeclination / 180.0 * 3.1415927)) / 15;
double xMoon = 0;
double yMoon = 0;
double zMoon = 0;
bool shadow = false;
bool eclipsed = false;
switch (planet)
{
case 10: // IO
xMoon = galDetails.Satellite1.ApparentRectangularCoordinates.X;
yMoon = galDetails.Satellite1.ApparentRectangularCoordinates.Y;
zMoon = galDetails.Satellite1.ApparentRectangularCoordinates.Z;
eclipsed = galDetails.Satellite1.bInEclipse;
shadow = galDetails.Satellite1.bInShadowTransit;
break;
case 11: //Europa
xMoon = galDetails.Satellite2.ApparentRectangularCoordinates.X;
yMoon = galDetails.Satellite2.ApparentRectangularCoordinates.Y;
zMoon = galDetails.Satellite2.ApparentRectangularCoordinates.Z;
eclipsed = galDetails.Satellite2.bInEclipse;
shadow = galDetails.Satellite2.bInShadowTransit;
break;
case 12: //Ganymede
xMoon = galDetails.Satellite3.ApparentRectangularCoordinates.X;
yMoon = galDetails.Satellite3.ApparentRectangularCoordinates.Y;
zMoon = galDetails.Satellite3.ApparentRectangularCoordinates.Z;
eclipsed = galDetails.Satellite3.bInEclipse;
shadow = galDetails.Satellite3.bInShadowTransit;
break;
case 13: //Callisto
xMoon = galDetails.Satellite4.ApparentRectangularCoordinates.X;
yMoon = galDetails.Satellite4.ApparentRectangularCoordinates.Y;
zMoon = galDetails.Satellite4.ApparentRectangularCoordinates.Z;
eclipsed = galDetails.Satellite4.bInEclipse;
shadow = galDetails.Satellite4.bInShadowTransit;
break;
case 14: // IO Shadow
xMoon = galDetails.Satellite1.ApparentShadowRectangularCoordinates.X;
yMoon = galDetails.Satellite1.ApparentShadowRectangularCoordinates.Y;
zMoon = galDetails.Satellite1.ApparentShadowRectangularCoordinates.Z * .9;
shadow = galDetails.Satellite1.bInShadowTransit;
break;
case 15: //Europa Shadow
xMoon = galDetails.Satellite2.ApparentShadowRectangularCoordinates.X;
yMoon = galDetails.Satellite2.ApparentShadowRectangularCoordinates.Y;
zMoon = galDetails.Satellite2.ApparentShadowRectangularCoordinates.Z * .9;
shadow = galDetails.Satellite2.bInShadowTransit;
break;
case 16: //Ganymede Shadow
xMoon = galDetails.Satellite3.ApparentShadowRectangularCoordinates.X;
yMoon = galDetails.Satellite3.ApparentShadowRectangularCoordinates.Y;
zMoon = galDetails.Satellite3.ApparentShadowRectangularCoordinates.Z * .9;
shadow = galDetails.Satellite3.bInShadowTransit;
break;
case 17: //Callisto Shadow
xMoon = galDetails.Satellite4.ApparentShadowRectangularCoordinates.X;
yMoon = galDetails.Satellite4.ApparentShadowRectangularCoordinates.Y;
zMoon = galDetails.Satellite4.ApparentShadowRectangularCoordinates.Z * .9;
shadow = galDetails.Satellite4.bInShadowTransit;
break;
}
double xTemp;
double yTemp;
double radians = jupPhisical.P / 180.0 * 3.1415927;
xTemp = xMoon * Math.Cos(radians) - yMoon * Math.Sin(radians);
yTemp = xMoon * Math.Sin(radians) + yMoon * Math.Cos(radians);
xMoon = xTemp;
yMoon = yTemp;
return(new AstroRaDec(jupDetails.ApparentGeocentricRA - (xMoon * raScale), jupDetails.ApparentGeocentricDeclination + yMoon * scale, jupDetails.ApparentGeocentricDistance + (zMoon * jupiterDiameter / 2), shadow, eclipsed));
}
}
public static AstroRaDec EclipticToJ2000(double l, double b, double jNow)
{
CAA2DCoordinate radec = CAACoordinateTransformation.Ecliptic2Equatorial(l, b, CAANutation.TrueObliquityOfEcliptic(jNow));
return(new AstroRaDec(radec.X, radec.Y, 0, false, false));
}
//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 = CAACoordinateTransformation.DegreesToRadians(Lambda0);
double Beta0 = 63.2818 - 0.00394 * T;
double Beta0rad = CAACoordinateTransformation.DegreesToRadians(Beta0);
//Step 2
double l0 = CAAEarth.EclipticLongitude(JD);
double l0rad = CAACoordinateTransformation.DegreesToRadians(l0);
double b0 = CAAEarth.EclipticLatitude(JD);
double b0rad = CAACoordinateTransformation.DegreesToRadians(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 = CAACoordinateTransformation.DegreesToRadians(l);
b = CAAMars.EclipticLatitude(JD2);
brad = CAACoordinateTransformation.DegreesToRadians(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 = CAAElliptical.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 = CAACoordinateTransformation.RadiansToDegrees(lambdarad);
double betarad = Math.Atan2(z, Math.Sqrt(x * x + y * y));
double beta = CAACoordinateTransformation.RadiansToDegrees(betarad);
//Step 6
details.DE = CAACoordinateTransformation.RadiansToDegrees(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 = CAACoordinateTransformation.DegreesToRadians(N);
double ldash = l - 0.00697 / r;
double ldashrad = CAACoordinateTransformation.DegreesToRadians(ldash);
double bdash = b - 0.000225 * (Math.Cos(lrad - Nrad) / r);
double bdashrad = CAACoordinateTransformation.DegreesToRadians(bdash);
//Step 8
details.DS = CAACoordinateTransformation.RadiansToDegrees(Math.Asin(-Math.Sin(Beta0rad) * Math.Sin(bdashrad) - Math.Cos(Beta0rad) * Math.Cos(bdashrad) * Math.Cos(Lambda0rad - ldashrad)));
//Step 9
double W = CAACoordinateTransformation.MapTo0To360Range(11.504 + 350.89200025 * (JD - LightTravelTime - 2433282.5));
//Step 10
double e0 = CAANutation.MeanObliquityOfEcliptic(JD);
double e0rad = CAACoordinateTransformation.DegreesToRadians(e0);
CAA2DCoordinate PoleEquatorial = CAACoordinateTransformation.Ecliptic2Equatorial(Lambda0, Beta0, e0);
double alpha0rad = CAACoordinateTransformation.HoursToRadians(PoleEquatorial.X);
double delta0rad = CAACoordinateTransformation.DegreesToRadians(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 = CAACoordinateTransformation.RadiansToHours(alpharad);
double deltarad = Math.Atan2(v, Math.Sqrt(x * x + u * u));
double delta = CAACoordinateTransformation.RadiansToDegrees(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 = CAACoordinateTransformation.MapTo0To360Range(W - CAACoordinateTransformation.RadiansToDegrees(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 = CAACoordinateTransformation.DegreesToRadians(Lambda0);
lambda += NutationInLongitude / 3600;
lambdarad = CAACoordinateTransformation.DegreesToRadians(lambda);
e0 += NutationInObliquity / 3600;
e0rad = CAACoordinateTransformation.DegreesToRadians(e0rad);
//Step 16
CAA2DCoordinate ApparentPoleEquatorial = CAACoordinateTransformation.Ecliptic2Equatorial(Lambda0, Beta0, e0);
double alpha0dash = CAACoordinateTransformation.HoursToRadians(ApparentPoleEquatorial.X);
double delta0dash = CAACoordinateTransformation.DegreesToRadians(ApparentPoleEquatorial.Y);
CAA2DCoordinate ApparentMars = CAACoordinateTransformation.Ecliptic2Equatorial(lambda, beta, e0);
double alphadash = CAACoordinateTransformation.HoursToRadians(ApparentMars.X);
double deltadash = CAACoordinateTransformation.DegreesToRadians(ApparentMars.Y);
//Step 17
details.P = CAACoordinateTransformation.MapTo0To360Range(CAACoordinateTransformation.RadiansToDegrees(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);
CAA2DCoordinate SunEquatorial = CAACoordinateTransformation.Ecliptic2Equatorial(SunLambda, SunBeta, e0);
details.X = CAAMoonIlluminatedFraction.PositionAngle(SunEquatorial.X, SunEquatorial.Y, alpha, delta);
//Step 19
details.d = 9.36 / DELTA;
details.k = CAAIlluminatedFraction.IlluminatedFraction(r, R, DELTA);
details.q = (1 - details.k) * details.d;
return(details);
}