Last night I happened to start an imaging run about 10 minutes before the target crossed the meridian. The exposure time for the image was 30 minutes. After the flip occured, the autoguider did not guide correctly in the DEC axis. I aborted the run and restarted it after the target had passed the meridian; the guiding was OK then. This problem seems repeatable since the same thing happened the previous night. It seems like the sign of the DEC axis guide speed might be wrong after the flip (?)

Oops, forgot to attach the log.

ccdap20080919_194800.log (8 Kb, 21 downloads) Autoguider problem

Hi Richard,

When starting in the east, you must take at least one image to set the guide calibration - it is just the way CCDAP is architected. If you want to start just before meridian crossing, then take a 5 sec. throwaway image before going into the 30 minute ones. Or, start your run after the target has crossed the meridian.