I'm pretty sure this topic has been covered previously, but I haven't found a satisfactory explanation for the occasional 8-15 arc-second "bounce" that occurs on my GM811.? I'm running Gemini 2 L5, PHD2 for guiding, and N.I.N.A on a Celestron 9.25 Edge HD, using a Lodestar X2 guide camera and an OAG.? From the PHD2 log (see attached) the bounce occurs before any corrections are applied - that is, PHD2 is not commanding the RA motor prior to the bounce, but immediately starts correcting it..? Bounces are rare and aperiodic but they bug me.? They do not appear to be related to RA position (on a different night they will occur more often or less often, usually more often).? Calibration looks great and aside from the bounce, tracking looks excellent.? For anyone with expertise with the PHD2 log file, section 8 at 00:38 shows a good example of this.
Any plausible explanations would be appreciated.? I've so far ruled out earthquakes and curious raccoons, and I don't think it's wind but I'm not sure.
