/// <summary>
/// Calculates solar position for a given location and point in time
/// </summary>
/// <param name="date">time and date calculate for</param>
/// <param name="latitude">latitude in degrees</param>
/// <param name="longitude">longitude in degrees</param>
/// <returns></returns>
public static SunPosition GetPosition(DateTime date, double latitude, double longitude)
{
double lw = Constants.Rad * -longitude;
double phi = Constants.Rad * latitude;
double d = Calendar.ToDays(date);
SunCoordinates c = Sun.Coordinates(d);
double H = Position.SiderealTime(d, lw) - c.RightAscension;
return(new SunPosition
{
Azimuth = Position.Azimuth(H, phi, c.Declination),
Altitude = Position.Altitude(H, phi, c.Declination)
});
}
/// <summary>
/// Calculates lunar position for a given location and point in time
///
/// based on http://aa.quae.nl/en/reken/hemelpositie.html formulas
/// </summary>
/// <param name="date">time and date calculate for</param>
/// <param name="latitude">latitude in degrees</param>
/// <param name="longitude">longitude in degrees</param>
/// <returns></returns>
public static MoonPosition GetMoonPosition(DateTime date, double latitude, double longitude)
{
var lw = Constants.Rad * -longitude;
var phi = Constants.Rad * latitude;
var d = Calendar.ToDays(date);
var c = Moon.Coordinates(d);
var H = Position.SiderealTime(d, lw) - c.RightAscension;
var h = Position.Altitude(H, phi, c.Declination);
// formula 14.1 of "Astronomical Algorithms" 2nd edition by Jean Meeus (Willmann-Bell, Richmond) 1998.
var pa = Math.Atan2(Math.Sin(H), Math.Tan(phi) * Math.Cos(c.Declination) - Math.Sin(c.Declination) * Math.Cos(H));
h += Moon.AstroRefraction(h); // altitude correction for refraction
return(new MoonPosition
{
Azimuth = Position.Azimuth(H, phi, c.Declination),
Altitude = h,
Distance = c.Distance,
ParallacticAngle = pa
});
}
