Guide Star lost and repositioning

Question … when the guide star is lost, does SGP attempt to plate solve back to the target prior to reaquiring the guide star? There was a poster on CN who was mystified as to why he ended up doing a tracked mosaic through the skies while imaging a DSO … turns out that there were periodic clouds that caused the guidestar to get lost, and by the time another could be acquired the DSO had moved out of the frame and the new guidestar was in the wrong position. It would make sense that upon loss of a guidestar SGP would reposition by plate solving and THEN attempt to reacquire the guidestar to prevent this … does it? Thx!

As I understand it, if SGP enters recovery mode (assuming that you have it enabled) AND you have centering enabled for the target, SGP will attempt a center every time it attempts recovery.

The sequence I have observed, and which I think is the most logical is the following:

  1. PHD2 loses the guide star
  2. SGP stops any current image in process
  3. SGP waits for PDH2 to reacquire some guide star, may not be the one it was using
  4. SGP does a plate solve centering process. SGP will disable guiding during this center process.
  5. Guiding is turned back on and Imaging is resumed

It is a good idea to wait for PDH2 to reestablish guiding before doing the platesolve/center. The main reason, is if it did the center first, there is no guarantee that guiding could be reestablished, so may well have been a waste of time.