/// <summary>
/// Compute solar time for given julian date, time fraction, angle, latitude and direction.
/// </summary>
/// <param name="julianDate">
/// Julian date of solar time to be computed.
/// </param>
/// <param name="timeFraction">
/// Time fraction of the day of solar time to be computed.
/// </param>
/// <param name="angle">
/// Sun's angle of solar time to be computed.
/// </param>
/// <param name="latitude">
/// Location's latitude.
/// </param>
/// <param name="direction">
/// <see cref="Direction" /> value which determine whether sun is before or after mid day.
/// </param>
/// <returns>
/// Solar time for given julian date, time fraction, angle, latitude and direction.
/// </returns>
internal static double ComputeSolarTime(double julianDate, double timeFraction, double angle, double latitude, Direction direction)
{
var sunDeclination = ComputeSunDeclination(julianDate + timeFraction);
var midDay = ComputeMidDay(julianDate, timeFraction);
var solarTime = 0.0666666666666667 *
AngleMath.InverseCosineInDegree((-AngleMath.SineOfDegree(angle) -
(AngleMath.SineOfDegree(sunDeclination) * AngleMath.SineOfDegree(latitude))) /
(AngleMath.CosineOfDegree(sunDeclination) * AngleMath.CosineOfDegree(latitude)));
return(midDay + (direction == Direction.CounterClockwise ? -solarTime : solarTime));
}
/// <summary>
/// Compute sun's right ascension for given mean obliquity and ecliptic longitude.
/// </summary>
private static double ComputeSunRightAscension(double eclipticMeanObliquity, double sunEclipticLongitude)
{
return(AngleMath.InverseTangent2InDegree(AngleMath.CosineOfDegree(eclipticMeanObliquity) * AngleMath.SineOfDegree(sunEclipticLongitude),
AngleMath.CosineOfDegree(sunEclipticLongitude)) /
15.0);
}