public EquatorialCoordinate(Angle ra, Angle dec)
{
_ra = ra; _dec = dec;
}
// All wikipedia below is accessed 7 may 2012
/// <summary>
/// Calculates the alt/az coordinates on the specified time and view coordinates
/// </summary>
/// <param name="moment"></param>
/// <param name="longitude"></param>
/// <param name="latitude"></param>
/// <returns></returns>
public HorizontalCoordinate GetHorizontalCoordinate(DateTimeOffset moment, Angle longitude, Angle latitude)
{
// Careful reading of http://en.wikipedia.org/wiki/Hour_angle#Relation_with_the_right_ascension
var hourangle = moment.GreenwichMeanSiderialTime() - longitude - RightAscention;
// Code adapted from http://en.wikipedia.org/wiki/Horizontal_coordinate_system#equatorial_to_horizontal 20120504
// This is some sphere trigonometry
var sinAlt = sin(latitude) * sin(Declination) + cos(latitude) * cos(Declination) * cos(hourangle);
var cosAzCosAlt = cos(latitude) * sin(Declination) - sin(latitude) * cos(Declination) * cos(hourangle);
var sinAzCosAlt = -cos(Declination) * sin(hourangle);
var radius = Pythagoras(cosAzCosAlt, sinAzCosAlt);
// Using Atan2 makes sure that the angle from the right quadrant is calculated
var azimuth = (Angle)Math.Atan2(sinAzCosAlt, cosAzCosAlt);
var altitude = (Angle)Math.Atan2(sinAlt, radius);
var test = Pythagoras(radius, sinAlt);
return(new HorizontalCoordinate(altitude, azimuth));
}
public HorizontalCoordinate(Angle alt, Angle az)
{
_alt = alt.Normalized; _az = az.Normalized;
}
