Re: Adjust CP4 Clock Frequency

Ray Gralak


So Atrack is essentially an autoguiding program. It's been done before in many different ways. Closed loop guiding is usually more accurate, so nothing new here. Wait for machine learning though and you will see improvements without closed loop responses.

-Ray Gralak
Author of APCC (Astro-Physics Command Center):
Author of PEMPro V3:
Author of Astro-Physics V2 ASCOM Driver:

-----Original Message-----
From: [] On Behalf Of Craig Young
Sent: Tuesday, May 5, 2020 7:31 PM
Subject: Re: [ap-gto] Adjust CP4 Clock Frequency

I do agree with you that errors in polar alignment, tube flexure, mirror shift, cables, etc can all contribute to factors
that will reduce the effectiveness of using APCC for long duration unguided imaging on larger SCTs. I have seen
this also on Parmount mounts where ATrack is used to correct tracking over long periods of time, so it is not just
an AP problem. ATrack doesn't really care if the sidereal tracking rate is wrong or polar alignment or any other
problem with the system, it is similar to using an autoguider which also corrects tracking, but in a different way. So
there is no real need to try and diagnose the system when it is not really needed.

It is best to simply accept the limitations of the system, which includes the mount, the optical train, the pier and
foundation, sky conditions, etc and just plan to use an autoguider or a program like ATrack.


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