Hi John and Chris, I think I'v got it now. Our mount is parallactic. So CdC sends RA and Dec to mount controller, which then will calculate AltAz regarding time. Mount then goes to AltAz. As this will last some time, controller has to recalculate AltAz. When target is reached, normal guiding in Az will start. All OK? Can I do it in this way??
Ulrich --- In [email protected], John Mahony <[EMAIL PROTECTED]> wrote: > > Since the relation between alt-az and RA-dec coordinates is time- dependent, if CdC were to send alt-az coordinates for pointing, it would have to know how fast your scope moves, so it could send the scope to where the object _will be_, at the time it gets there. That adds even more complexity, since the "time to get there" will depend on the distance to the target. RA-dec is the sky's natural coordinate system, so charting programs start with that. > > I'm assuming your mount is alt-az, otherwise there's no reason to be concerned with alt-az coordinates at all. So in this case your mount controller will need to routinely do the coordinate transformation anyway. > > -John > > > > > ----- Original Message ---- > > From: ulrichkorth <[EMAIL PROTECTED]> > > > > Hi Chris, > > next question from beginner: Is it true, that NOT CdC - or any other > > PC-Astro-Program - will always calculate Altitude and Azimut but > > this is task of the scope's controller itself. That was the > > intention of my first question - as we build the scopes controller > > ourselves we would like not to calculate here - but would like to > > get these data from PC, which has more calculation power and more > > accuracy. > > Ulrich > > > > --- In [email protected], Chris Rowland > > wrote: > > > > > > Ra and Dec are better for pointing to celestial objects because > > they > > > don't change as the Earth rotates. > > > > > > Look for ASCOM for a way to communicate with Ceil. > > > > > > Chris > > > > > > ulrichkorth wrote: > > > > Hi sky friends, > > > > we are beginners and want to use ciel. The communication to > > teleskope > > > > works well. But why does ciel only send RA and DEC and NOT also > > ALT > > > > and Azimut?? > > > > As we are building the teleskope control and SW ourselves it > > would be > > > > easier to have ALT and Azimut from ciel. > > > > > > > > For some help and advice we would be very thankful. > > > > > > > > Kind regards > > > > Ulrich and Michael Korth >
