bool ScopeSim::Goto(double ra,double dec)
{
DEBUGF(DBG_SIMULATOR, "Goto - Celestial reference frame target right ascension %lf(%lf) declination %lf", ra * 360.0 / 24.0, ra, dec);
if (ISS_ON == IUFindSwitch(&CoordSP,"TRACK")->s)
{
char RAStr[32], DecStr[32];
fs_sexa(RAStr, ra, 2, 3600);
fs_sexa(DecStr, dec, 2, 3600);
CurrentTrackingTarget.ra = ra;
CurrentTrackingTarget.dec = dec;
DEBUG(DBG_SIMULATOR, "Goto - tracking requested");
}
// Call the alignment subsystem to translate the celestial reference frame coordinate
// into a telescope reference frame coordinate
TelescopeDirectionVector TDV;
ln_hrz_posn AltAz;
if (TransformCelestialToTelescope(ra, dec, 0.0, TDV))
{
// The alignment subsystem has successfully transformed my coordinate
AltitudeAzimuthFromTelescopeDirectionVector(TDV, AltAz);
}
else
{
// The alignment subsystem cannot transform the coordinate.
// Try some simple rotations using the stored observatory position if any
bool HavePosition = false;
ln_lnlat_posn Position;
if ((NULL != IUFindNumber(&LocationNP, "LAT")) && ( 0 != IUFindNumber(&LocationNP, "LAT")->value)
&& (NULL != IUFindNumber(&LocationNP, "LONG")) && ( 0 != IUFindNumber(&LocationNP, "LONG")->value))
{
// I assume that being on the equator and exactly on the prime meridian is unlikely
Position.lat = IUFindNumber(&LocationNP, "LAT")->value;
Position.lng = IUFindNumber(&LocationNP, "LONG")->value;
HavePosition = true;
}
struct ln_equ_posn EquatorialCoordinates;
// libnova works in decimal degrees
EquatorialCoordinates.ra = ra * 360.0 / 24.0;
EquatorialCoordinates.dec = dec;
if (HavePosition)
{
ln_get_hrz_from_equ(&EquatorialCoordinates, &Position, ln_get_julian_from_sys(), &AltAz);
TDV = TelescopeDirectionVectorFromAltitudeAzimuth(AltAz);
switch (GetApproximateMountAlignment())
{
case ZENITH:
break;
case NORTH_CELESTIAL_POLE:
// Rotate the TDV coordinate system clockwise (negative) around the y axis by 90 minus
// the (positive)observatory latitude. The vector itself is rotated anticlockwise
TDV.RotateAroundY(Position.lat - 90.0);
break;
case SOUTH_CELESTIAL_POLE:
// Rotate the TDV coordinate system anticlockwise (positive) around the y axis by 90 plus
// the (negative)observatory latitude. The vector itself is rotated clockwise
TDV.RotateAroundY(Position.lat + 90.0);
break;
}
AltitudeAzimuthFromTelescopeDirectionVector(TDV, AltAz);
}
else
{
// The best I can do is just do a direct conversion to Alt/Az
TDV = TelescopeDirectionVectorFromEquatorialCoordinates(EquatorialCoordinates);
AltitudeAzimuthFromTelescopeDirectionVector(TDV, AltAz);
}
}
// My altitude encoder runs -90 to +90
if ((AltAz.alt > 90.0) || (AltAz.alt < -90.0))
{
DEBUG(DBG_SIMULATOR, "Goto - Altitude out of range");
// This should not happen
return false;
}
// My polar encoder runs 0 to +360
if ((AltAz.az > 360.0) || (AltAz.az < -360.0))
{
DEBUG(DBG_SIMULATOR, "Goto - Azimuth out of range");
// This should not happen
return false;
}
if (AltAz.az < 0.0)
{
DEBUG(DBG_SIMULATOR, "Goto - Azimuth negative");
AltAz.az = 360.0 + AltAz.az;
}
DEBUGF(DBG_SIMULATOR, "Goto - Scope reference frame target altitude %lf azimuth %lf", AltAz.alt, AltAz.az);
GotoTargetMicrostepsDEC = int(AltAz.alt * MICROSTEPS_PER_DEGREE);
if (GotoTargetMicrostepsDEC == CurrentEncoderMicrostepsDEC)
AxisStatusDEC = STOPPED;
else
{
if (GotoTargetMicrostepsDEC > CurrentEncoderMicrostepsDEC)
AxisDirectionDEC = FORWARD;
else
AxisDirectionDEC = REVERSE;
AxisStatusDEC = SLEWING_TO;
}
GotoTargetMicrostepsRA = int(AltAz.az * MICROSTEPS_PER_DEGREE);
if (GotoTargetMicrostepsRA == CurrentEncoderMicrostepsRA)
AxisStatusRA = STOPPED;
else
{
if (GotoTargetMicrostepsRA > CurrentEncoderMicrostepsRA)
AxisDirectionRA = (GotoTargetMicrostepsRA - CurrentEncoderMicrostepsRA) < MICROSTEPS_PER_REVOLUTION / 2.0 ? FORWARD : REVERSE;
else
AxisDirectionRA = (CurrentEncoderMicrostepsRA - GotoTargetMicrostepsRA) < MICROSTEPS_PER_REVOLUTION / 2.0 ? REVERSE : FORWARD;
AxisStatusRA = SLEWING_TO;
}
TrackState = SCOPE_SLEWING;
EqNP.s = IPS_BUSY;
return true;
}
ln_hrz_posn NexStarEvo::AltAzFromRaDec(double ra, double dec, double ts)
{
// Call the alignment subsystem to translate the celestial reference frame coordinate
// into a telescope reference frame coordinate
TelescopeDirectionVector TDV;
ln_hrz_posn AltAz;
if (TransformCelestialToTelescope(ra, dec, ts, TDV))
{
// The alignment subsystem has successfully transformed my coordinate
AltitudeAzimuthFromTelescopeDirectionVector(TDV, AltAz);
}
else
{
// The alignment subsystem cannot transform the coordinate.
// Try some simple rotations using the stored observatory position if any
bool HavePosition = false;
ln_lnlat_posn Position;
if ((NULL != IUFindNumber(&LocationNP, "LAT")) && (0 != IUFindNumber(&LocationNP, "LAT")->value) &&
(NULL != IUFindNumber(&LocationNP, "LONG")) && (0 != IUFindNumber(&LocationNP, "LONG")->value))
{
// I assume that being on the equator and exactly on the prime meridian is unlikely
Position.lat = IUFindNumber(&LocationNP, "LAT")->value;
Position.lng = IUFindNumber(&LocationNP, "LONG")->value;
HavePosition = true;
}
struct ln_equ_posn EquatorialCoordinates;
// libnova works in decimal degrees
EquatorialCoordinates.ra = ra * 360.0 / 24.0;
EquatorialCoordinates.dec = dec;
if (HavePosition)
{
ln_get_hrz_from_equ(&EquatorialCoordinates, &Position, ln_get_julian_from_sys() + ts, &AltAz);
TDV = TelescopeDirectionVectorFromAltitudeAzimuth(AltAz);
switch (GetApproximateMountAlignment())
{
case ZENITH:
break;
case NORTH_CELESTIAL_POLE:
// Rotate the TDV coordinate system clockwise (negative) around the y axis by 90 minus
// the (positive)observatory latitude. The vector itself is rotated anticlockwise
TDV.RotateAroundY(Position.lat - 90.0);
break;
case SOUTH_CELESTIAL_POLE:
// Rotate the TDV coordinate system anticlockwise (positive) around the y axis by 90 plus
// the (negative)observatory latitude. The vector itself is rotated clockwise
TDV.RotateAroundY(Position.lat + 90.0);
break;
}
AltitudeAzimuthFromTelescopeDirectionVector(TDV, AltAz);
}
else
{
// The best I can do is just do a direct conversion to Alt/Az
TDV = TelescopeDirectionVectorFromEquatorialCoordinates(EquatorialCoordinates);
AltitudeAzimuthFromTelescopeDirectionVector(TDV, AltAz);
}
}
return AltAz;
}
