public void NutationInObliquityTest()
{
var date = new AASDate(1987, 4, 10, 0, 0, 0, true);
double nutationInEcliptic = AASNutation.NutationInObliquity(date.Julian);
Assert.Equal(9.4425206987573933, nutationInEcliptic);
}
public void MeanObliquityOfEclipticTest()
{
var date = new AASDate(1987, 4, 10, 0, 0, 0, true);
double obliquity = AASNutation.MeanObliquityOfEcliptic(date.Julian);
Assert.Equal(23.440946290957317, obliquity);
}
public void NutationInLongitudeTest()
{
var date = new AASDate(1987, 4, 10, 0, 0, 0, true);
double nutationInLongitude = AASNutation.NutationInLongitude(date.Julian);
Assert.Equal(-3.7879310766037446, nutationInLongitude);
}
protected void CorrectForFK5SystemReduction()
{
double appGeoLon = GetGeocentricLongitude(vectorToEarthCorrected.x, vectorToEarthCorrected.y);
double appGeoLat = GetGeocentricLatitude(vectorToEarthCorrected.x, vectorToEarthCorrected.y, vectorToEarthCorrected.z);
double deltaLambdaFK5 = AASFK5.CorrectionInLongitude(appGeoLon, appGeoLat, jdeCorrected);
double deltaBetaFK5 = AASFK5.CorrectionInLatitude(appGeoLon, jdeCorrected);
lambdaFK5 = lambdaAberration + deltaLambdaFK5;
betaFK5 = betaAberration + deltaBetaFK5;
//correct for nutation
double deltaPhi = AASNutation.NutationInLongitude(jdeCorrected) / 3600;
double deltaEpsilon = AASNutation.NutationInObliquity(jdeCorrected) / 3600;
epsilon = AASNutation.TrueObliquityOfEcliptic(jdeCorrected);
double lambdaNutation = lambdaFK5 + deltaPhi;
double betaNutation = betaFK5 + deltaEpsilon;
//x=RA in decimal hours, y=dec in degrees
AAS2DCoordinate equatorial = AASCoordinateTransformation.Ecliptic2Equatorial(lambdaNutation, betaNutation, epsilon);
equatorialCoords.RA = new HourAngle(equatorial.X);
equatorialCoords.Declination = new DegreesAngle(equatorial.Y);
}
//obliquity of the ecliptic with correction
private double GetEpsilonCorrected()
{
double T = (jd - 2451545.0) / 36525;
double epsilon0 = AASNutation.MeanObliquityOfEcliptic(jd);
double omega = 125.04 - 1934.136 * T;
double deltaEpsilon = .00256 * Math.Cos(omega * M.DEG2RAD);
return(epsilon0 + deltaEpsilon);
}
private void CalculateEquatorialPosition()
{
DegreesAngle ecLon = new DegreesAngle(AASMoon.EclipticLongitude(jd));
DegreesAngle ecLat = new DegreesAngle(AASMoon.EclipticLatitude(jd));
double epsilon = AASNutation.TrueObliquityOfEcliptic(jd);
AAS2DCoordinate eq = AASCoordinateTransformation.Ecliptic2Equatorial(ecLon.Get(), ecLat.Get(), epsilon);
equatorialCoords.RA = new HourAngle(eq.X);
equatorialCoords.Declination = new DegreesAngle(eq.Y);
}
//obliquity of the ecliptic
protected double GetDeltaEpsilon()
{
return(AASNutation.MeanObliquityOfEcliptic(jd));
}
public void Ecliptic2EquatorialTest(double JD, double apparentEclipticLongitude, double apparentEclipticLatitude, double expectedX, double expectedY)
{
var equatorial = AASCoordinateTransformation.Ecliptic2Equatorial(apparentEclipticLongitude, apparentEclipticLatitude, AASNutation.TrueObliquityOfEcliptic(JD));
Assert.Equal(expectedX, equatorial.X);
Assert.Equal(expectedY, equatorial.Y);
}
public static AAS2DCoordinate MoonPosition(DateTime dateTime)
{
dateTime = dateTime.ToUniversalTime(); // NOTE: time must be converted to Universal Time
//Calculate the topocentric horizontal position of the Moon
AASDate dateMoonCalc = new AASDate(dateTime.Year, dateTime.Month, dateTime.Day, dateTime.Hour, dateTime.Minute, dateTime.Second, true);
double JDMoon = dateMoonCalc.Julian + AASDynamicalTime.DeltaT(dateMoonCalc.Julian) / 86400.0;
double MoonLong = AASMoon.EclipticLongitude(JDMoon);
double MoonLat = AASMoon.EclipticLatitude(JDMoon);
AAS2DCoordinate Equatorial = AASCoordinateTransformation.Ecliptic2Equatorial(MoonLong, MoonLat, AASNutation.TrueObliquityOfEcliptic(JDMoon));
double MoonRad = AASMoon.RadiusVector(JDMoon);
MoonRad /= 149597870.691; //Convert KM to AU
AAS2DCoordinate MoonTopo = AASParallax.Equatorial2Topocentric(Equatorial.X, Equatorial.Y, MoonRad, RT_LONG, RT_LAT, RT_HEIGHT, JDMoon);
double AST = AASSidereal.ApparentGreenwichSiderealTime(dateMoonCalc.Julian);
double LongtitudeAsHourAngle = AASCoordinateTransformation.DegreesToHours(RT_LONG);
double LocalHourAngle = AST - LongtitudeAsHourAngle - MoonTopo.X;
AAS2DCoordinate MoonHorizontal = AASCoordinateTransformation.Equatorial2Horizontal(LocalHourAngle, MoonTopo.Y, RT_LAT);
MoonHorizontal.Y += AASRefraction.RefractionFromTrue(MoonHorizontal.Y, 1013, 10);
//The result above should be that we have a rising Moon at Y degrees above the horizon at azimuth X degrees east of the southern horizon
//NOTE: for azimuth west is considered positive, to get east as positive subtract the result from 360
return(MoonHorizontal);
}
public static AAS2DCoordinate SunPosition(DateTime dateTime)
{
var bHighPrecision = false;
dateTime = dateTime.ToUniversalTime(); // NOTE: time must be converted to Universal Time
//Calculate the topocentric horizontal position of the Sun
AASDate dateSunCalc = new AASDate(dateTime.Year, dateTime.Month, dateTime.Day, dateTime.Hour, dateTime.Minute, dateTime.Second, true);
double JDSun = dateSunCalc.Julian + AASDynamicalTime.DeltaT(dateSunCalc.Julian) / 86400.0;
double SunLong = AASSun.ApparentEclipticLongitude(JDSun, bHighPrecision);
double SunLat = AASSun.ApparentEclipticLatitude(JDSun, bHighPrecision);
AAS2DCoordinate Equatorial = AASCoordinateTransformation.Ecliptic2Equatorial(SunLong, SunLat, AASNutation.TrueObliquityOfEcliptic(JDSun));
double SunRad = AASEarth.RadiusVector(JDSun, bHighPrecision);
AAS2DCoordinate SunTopo = AASParallax.Equatorial2Topocentric(Equatorial.X, Equatorial.Y, SunRad, RT_LONG, RT_LAT, RT_HEIGHT, JDSun);
double AST = AASSidereal.ApparentGreenwichSiderealTime(dateSunCalc.Julian);
double LongtitudeAsHourAngle = AASCoordinateTransformation.DegreesToHours(RT_LONG);
double LocalHourAngle = AST - LongtitudeAsHourAngle - SunTopo.X;
AAS2DCoordinate SunHorizontal = AASCoordinateTransformation.Equatorial2Horizontal(LocalHourAngle, SunTopo.Y, RT_LAT);
SunHorizontal.Y += AASRefraction.RefractionFromTrue(SunHorizontal.Y, 1013, 10);
//The result above should be that we have a setting Sun at Y degrees above the horizon at azimuth X degrees south of the westerly horizon
//NOTE: for azimuth west is considered positive, to get east as positive subtract the result from 360
return(SunHorizontal);
}
//obliquity of the ecliptic
private double GetEpsilon()
{
return(AASNutation.MeanObliquityOfEcliptic(jd));
}
public void TrueObliquityOfEclipticTest(double jd, double expectedTrueObliquity)
{
double trueObliquity = AASNutation.TrueObliquityOfEcliptic(jd);
Assert.Equal(expectedTrueObliquity, trueObliquity);
}
public void NutationInDeclinationTest(double x, double obliquity, double nutationInLongitude, double nutationInEcliptic, double expectedDeltaNutation)
{
double deltaNutation = AASNutation.NutationInDeclination(x, obliquity, nutationInLongitude, nutationInEcliptic);
Assert.Equal(expectedDeltaNutation, deltaNutation);
}
public void NutationInRightAscensionTest(double x, double y, double obliquity, double nutationInLongitude, double nutationInEcliptic, double expectedAlphaNutation)
{
double alphaNutation = AASNutation.NutationInRightAscension(x, y, obliquity, nutationInLongitude, nutationInEcliptic);
Assert.Equal(expectedAlphaNutation, alphaNutation);
}
public Coordinate GetMoonCoordinate(DateTime datetime)
{
AASDate date = new AASDate(datetime.Year, datetime.Month, datetime.Day, datetime.Hour, datetime.Minute, datetime.Second, true);
double JD = date.Julian + AASDynamicalTime.DeltaT(date.Julian) / 86400.0;
double MoonLong = AASMoon.EclipticLongitude(JD);
double MoonLat = AASMoon.EclipticLatitude(JD);
AAS2DCoordinate Equatorial = AASCoordinateTransformation.Ecliptic2Equatorial(MoonLong, MoonLat, AASNutation.TrueObliquityOfEcliptic(JD));
double MoonRad = AASMoon.RadiusVector(JD);
MoonRad /= 149597870.691; //Convert KM to AU
AAS2DCoordinate MoonTopo = AASParallax.Equatorial2Topocentric(Equatorial.X, Equatorial.Y, MoonRad, Location.Longitude, Location.Latitude, Location.Altitude, JD);
return(new Coordinate(MoonTopo.X, MoonTopo.Y));
}
public Coordinate GetSunCoordinate(DateTime datetime)
{
AASDate date = new AASDate(datetime.Year, datetime.Month, datetime.Day, datetime.Hour, datetime.Minute, datetime.Second, true);
double JD = date.Julian + AASDynamicalTime.DeltaT(date.Julian) / 86400.0;
double SunLong = AASSun.ApparentEclipticLongitude(JD, false);
double SunLat = AASSun.ApparentEclipticLatitude(JD, false);
AAS2DCoordinate equatorial = AASCoordinateTransformation.Ecliptic2Equatorial(SunLong, SunLat, AASNutation.TrueObliquityOfEcliptic(JD));
double SunRad = AASEarth.RadiusVector(JD, false);
// This line gives us RA & Declination.
AAS2DCoordinate SunTopo = AASParallax.Equatorial2Topocentric(equatorial.X, equatorial.Y, SunRad, Location.Longitude, Location.Latitude, Location.Altitude, JD);
return(new Coordinate(SunTopo.X, SunTopo.Y));
}
