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);
}
public void EclipticRectangularCoordinatesJ2000Test(double JD, bool bHighPrecision, double expectedX, double expectedY, double expectedZ)
{
AAS3DCoordinate sunCoord = AASSun.EclipticRectangularCoordinatesJ2000(JD, bHighPrecision);
Assert.Equal(expectedX, sunCoord.X);
Assert.Equal(expectedY, sunCoord.Y);
Assert.Equal(expectedZ, sunCoord.Z);
}
public void EquatorialRectangularCoordinatesMeanEquinoxTest(double JD, bool bHighPrecision, double expectedX, double expectedY, double expectedZ)
{
AAS3DCoordinate sunCoord = AASSun.EquatorialRectangularCoordinatesMeanEquinox(JD, bHighPrecision);
Assert.Equal(expectedX, sunCoord.X);
Assert.Equal(expectedY, sunCoord.Y);
Assert.Equal(expectedZ, sunCoord.Z);
}
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));
}
protected void CorrectForAberration()
{
double e = GetEarthEccentricity(jd);
double pi = GetEarthPerihelionLongitude(jd);
double theta = AASSun.GeometricEclipticLongitude(jdeCorrected);
double appGeoLon = GetGeocentricLongitude(vectorToEarthCorrected.x, vectorToEarthCorrected.y);
double appGeoLat = GetGeocentricLatitude(vectorToEarthCorrected.x, vectorToEarthCorrected.y, vectorToEarthCorrected.z);
double deltaLambda = GetAberrationDeltaLongitude(theta, appGeoLon, appGeoLat, e, pi);
double deltaBeta = GetAberrationDeltaLatitude(theta, appGeoLon, appGeoLat, e, pi);
lambdaAberration = appGeoLon + deltaLambda;
betaAberration = appGeoLat + deltaBeta;
}
public void GeometricEclipticLongitudeTest(double JD, bool bHighPrecision, double expectedLongitude)
{
double longitude = AASSun.GeometricEclipticLongitude(JD, bHighPrecision);
Assert.Equal(expectedLongitude, longitude);
}
public void ApparentEclipticLatitudeTest(double JD, bool bHighPrecision, double expectedLatitude)
{
double latitude = AASSun.ApparentEclipticLatitude(JD, bHighPrecision);
Assert.Equal(expectedLatitude, latitude);
}
