/// <summary>
/// Finds a theoretical home position for the telescope to return to. It will be pointing to the Celestial Pole, but in such a way that
/// CW bar should be nearly vertical, and there is no meridian flip involved.
/// </summary>
/// <param name="currentCoordinates"></param>
/// <returns></returns>
private Coordinates GetHomeCoordinates(Coordinates currentCoordinates)
{
double siderealTime = Astrometry.GetLocalSiderealTimeNow(profileService.ActiveProfile.AstrometrySettings.Longitude);
if (siderealTime > 24)
{
siderealTime -= 24;
}
if (siderealTime < 0)
{
siderealTime += 24;
}
double timeToMed = currentCoordinates.RA - siderealTime;
Coordinates returnCoordinates = new Coordinates(Angle.ByHours(0), Angle.ByDegree(0), Epoch.J2000);
if (profileService.ActiveProfile.AstrometrySettings.HemisphereType == Hemisphere.NORTHERN)
{
returnCoordinates.Dec = 89;
returnCoordinates.RA = siderealTime + 6 * Math.Sign(timeToMed);
}
if (profileService.ActiveProfile.AstrometrySettings.HemisphereType == Hemisphere.SOUTHERN)
{
returnCoordinates.Dec = -89;
returnCoordinates.RA = siderealTime + 6 * Math.Sign(timeToMed);
}
return(returnCoordinates);
}
private async Task <bool> MeasurePolarError(IProgress <ApplicationStatus> progress, Direction direction)
{
if (CameraInfo?.Connected == true)
{
cancelMeasureErrorToken?.Dispose();
cancelMeasureErrorToken = new CancellationTokenSource();
Task moveBackTask = Task.CompletedTask;
try {
var siderealTime = Astrometry.GetLocalSiderealTimeNow(profileService.ActiveProfile.AstrometrySettings.Longitude);
var latitude = Angle.ByDegree(profileService.ActiveProfile.AstrometrySettings.Latitude);
var dec = Angle.ByDegree(TelescopeInfo.Declination);
var hourAngle = Astrometry.GetHourAngle(Angle.ByHours(siderealTime), Angle.ByHours(TelescopeInfo.Coordinates.RA));
var altitude = Astrometry.GetAltitude(hourAngle, latitude, dec);
var azimuth = Astrometry.GetAzimuth(hourAngle, altitude, latitude, dec);
var altitudeSide = azimuth.Degree < 180 ? AltitudeSite.EAST : AltitudeSite.WEST;
Coordinates startPosition = telescopeMediator.GetCurrentPosition();
double poleErr = await CalculatePoleError(startPosition, progress, cancelMeasureErrorToken.Token);
moveBackTask = telescopeMediator.SlewToCoordinatesAsync(startPosition);
string poleErrString = Deg2str(Math.Abs(poleErr), 4);
cancelMeasureErrorToken.Token.ThrowIfCancellationRequested();
if (double.IsNaN(poleErr))
{
/* something went wrong */
progress.Report(new ApplicationStatus()
{
Status = string.Empty
});
return(false);
}
string msg = "";
if (direction == Direction.ALTITUDE)
{
if (profileService.ActiveProfile.AstrometrySettings.HemisphereType == Hemisphere.NORTHERN)
{
if (altitudeSide == AltitudeSite.EAST)
{
if (poleErr < 0)
{
msg = poleErrString + " too low";
}
else
{
msg = poleErrString + " too high";
}
}
else
{
if (poleErr < 0)
{
msg = poleErrString + " too high";
}
else
{
msg = poleErrString + " too low";
}
}
}
else
{
if (altitudeSide == AltitudeSite.EAST)
{
if (poleErr < 0)
{
msg = poleErrString + " too high";
}
else
{
msg = poleErrString + " too low";
}
}
else
{
if (poleErr < 0)
{
msg = poleErrString + " too low";
}
else
{
msg = poleErrString + " too high";
}
}
}
}
else if (direction == Direction.AZIMUTH)
{
//if northern
if (profileService.ActiveProfile.AstrometrySettings.HemisphereType == Hemisphere.NORTHERN)
{
if (poleErr < 0)
{
msg = poleErrString + " too east";
}
else
{
msg = poleErrString + " too west";
}
}
else
{
if (poleErr < 0)
{
msg = poleErrString + " too west";
}
else
{
msg = poleErrString + " too east";
}
}
}
progress.Report(new ApplicationStatus()
{
Status = msg
});
} catch (OperationCanceledException) {
} finally {
await moveBackTask;
}
/* Altitude
* Northern
* East side
* poleError < 0 -> too low
* poleError > 0 -> too high
* Azimuth
* Northern
* South side
* poleError < 0 -> too east
* poleError > 0 -> too west
*/
}
else
{
Notification.ShowWarning(Locale.Loc.Instance["LblNoCameraConnected"]);
}
return(true);
}
