Re: Continuation of the discussion using APCC CW up within the East Limit slews with SGPro #APCC

Ray Gralak



> How does APCC dynamic meridian delay work? 


It is “dynamic” because the meridian delay can automatically change when declination changes. I'm going to copy a paragraph out of the APCC help, which you can find at this link:


Instead of just a single meridian limit for all declinations, you can configure an arbitrary number of different limits at different declinations. This is useful because at each declination there can be a different hour angle at which the telescope will touch the pier.  In declination regions where the telescope can theoretically go the full 6 hours past in the west, the meridian limits can establish horizon tracking limits for the practical distance past the meridian where you can reasonably continue to work.  Likewise, in the east, they can set the practical horizon ahead of the meridian where you can reasonably start an image.


To configure the dynamic meridian delay values you use APCC’s Meridian Limit Explorer (perhaps in the daytime) to map the counterweight-up limits of your specific scope on your mount. The limits (meridian delays) will be different depending on the scope and the latitude of the site. Once you do it once, you will see that it is pretty easy to use. Here are three different links explaining the operation in more detail:


After defining the limits, when using APCC with SGPro, APCC will be able to automatically use the pre-defined limit for the mount’s current declination and pier side.


I hope this information helps to explain what “dynamic meridian delay” means.




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