Quote:
Originally Posted by Shiraz
there is a repeating RA pattern at the 230 sec worm fundamental, which suggests to me that the guiding is too slow to correct for rapid slope transitions in the PE. With 4 second exposures, mount response time and aggressiveness/hysteresis, your tracking loop is trying to (partially) correct for errors that happened maybe 8 or more seconds ago, which will mean that it could even be correcting in the wrong direction if the PE slope changes quickly. Have you tried guiding with short exposures - maybe 1 second - to speed up the guide loop? Also, do you have any raw PE data?
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Hi Ray,
I had not considered that as I generally don't try to chase the seeing but I might just give that a try. I have been doing sub exposures pretty long between 4-10 seconds and that is generally selected by CCDAP as a setting I have to ensure good guide stars. I have PEC data on the dome computer I will chase this up and post it here. Several PMX users in the southern hemisphere say that the correction does not see to work properly even when you reverse the side of the meridian and I a have found that too. Perhaps you will see a corresponding similarity.