public static AltAzm RaDec2AltAzm(Coordinates coord, LatLon location, DateTime time, double elevation)
{
var utils = new ASCOM.Astrometry.AstroUtils.AstroUtils();
var MJDdate = utils.CalendarToMJD(time.Day, time.Month, time.Year);
MJDdate += time.TimeOfDay.TotalDays;
var tfm = new ASCOM.Astrometry.Transform.Transform();
tfm.JulianDateTT = MJDdate;
tfm.SiteElevation = elevation * 1000;
tfm.SiteLatitude = location.Lat;
tfm.SiteLongitude = location.Lon;
tfm.SiteTemperature = 0;
tfm.SetApparent(coord.Ra, coord.Dec);
tfm.Refresh();
var res = new AltAzm(tfm.ElevationTopocentric, tfm.AzimuthTopocentric);
return res;
}
public static AltAzm RaDec2AltAzm2(Coordinates coord, LatLon location, DateTime UTCtime, double elevation)
{
var utils = new ASCOM.Astrometry.NOVAS.NOVAS31();
var ra = coord.Ra * 15;
var dec = coord.Dec;
var time = UTCtime.TimeOfDay.TotalHours;
var lat = location.Lat;
var lon = location.Lon;
var j200Time = utils.JulianDate((short)UTCtime.Year, (short)UTCtime.Month, (short)UTCtime.Day, time);
j200Time -= 2451545.0;
var LST = 100.46 + 0.985647 * j200Time + lon + 15 * time;
LST = LST.ToRange(0, 360);
var HA = (LST - ra).ToRange(0, 360);
var sinALT = Math.Sin(dec.ToRad()) * Math.Sin(lat.ToRad()) + Math.Cos(dec.ToRad()) * Math.Cos(lat.ToRad()) * Math.Cos(HA.ToRad());
var ALT = Math.Asin(sinALT);
var alt = ALT.ToDeg();
var cosA = (Math.Sin(dec.ToRad()) - Math.Sin(ALT) * Math.Sin(lat.ToRad())) / (Math.Cos(ALT) * Math.Cos(lat.ToRad()));
var A = Math.Acos(cosA).ToDeg();
var Azm = Math.Sin(HA.ToRad()) < 0 ? A : 360 - A;
return new AltAzm(alt, Azm);
}
public static Coordinates AltAzm2RaDec(AltAzm altAzm, LatLon location, DateTime time, double elevation)
{
var JDdate = JDtime(time);
var tfm = new ASCOM.Astrometry.Transform.Transform();
var jdtt = tfm.JulianDateTT;
//tfm.JulianDateTT = JDdate;
tfm.SiteElevation = elevation * 1000;
tfm.SiteLatitude = location.Lat;
tfm.SiteLongitude = location.Lon;
tfm.SiteTemperature = 0;
tfm.SetAzimuthElevation(altAzm.Azm, altAzm.Alt);
tfm.Refresh();
// var res = new Coordinates(tfm.RAJ2000, tfm.DecJ2000);
// var res = new Coordinates(tfm.RAApparent, tfm.DECApparent);
var res = new Coordinates(tfm.RATopocentric, tfm.DECTopocentric);
return res;
}
