Dithering in SGP requires you to set a Settling Option. What exactly is it monitoring to confirm that it has settled? When I watch the PHD graphs on my A-P Mach1GTO mount it seems to start the next image once the RA and Dec have converged on the X axis with PHD reporting the settling distance as less than the threshold.
My question is, what does it do with a mount that only guides in RA? My portable setup is an AstroTrac which doesn't have an Dec guiding. How does SGP/PHD tell that it is settled with a mount that only guides in RA? When I look at the PHD graph, there is some drift in Dec over multiple exposures because polar alignment isn't perfect so if PHD is looking for convergence of RA and Dec on the X-axis then at some point drift will exceed the settling distance. Will it reach a point where the convergence between Dec and RA will always exceed the settling distance, and thus never settle? Or will SGP ignore Dec altogether (Dec guiding is turned off in PHD) and just look for RA to settle on the X axis?
...Keith