Re: Valid Guide Rates for PEC on Gemini Level 4
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Thank you for those answers. I think Paul's ideas might be close to the mark.? I still don't quite "see" the issue in my mind's eye yet. I think now that the autoguide speed really applies to using PEC and Autoguiding actively AFTER the PEC curve has been generated.? The autoguide speed has zero to do with taking the PE data.? It can't because the video camera is just capturing the target star location in its image plane.? No autoguiding pulses are used at all in taking that tracking data. So the?autoguide speed recommendation must have to do after, with PEC turned on.? Then I can see how the?autoguide rate might come into play.?? However, if the corrections needed to be very fast, say for a very sharp worm or coupler induced error, the faster your autoguide rate that is "allowed" by Gemini would be able to counteract such severe trouble.? However, in my PEC experience, you want to "smooth out" any sharp impulses. That is why the Gemini-1 provides for you to run multiple PE runs, so the software can just average out the corrections.? You do not want to be "chasing the seeing" as the saying goes.?? If you?look at the PEC curves that typically go from -2 arcsec to?+ 2 arcsec over a worm period (4 minutes on G11) you would not need a very fast autoguide speed, so limiting that to 0.5 sidereal is sensible.? Anyway it will also matter if your FL is very high...so you are more sensitive to star movement.? At that point you might want to allow the autoguider to move the mount faster, at 0.8 of sidereal maybe.?? It's all one big experiment for us observers. Have fun, stay well, and (the lastest issue:thunderstorms!)?hope your power stays on! Michael On Mon, Aug 17, 2020 at 2:44 PM Brian Valente <bvalente@...> wrote:
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Michael Herman