Re: APPM Basic questions

Ray Gralak

Hi Linwood,

Have you already read the APCC help section for APPM? There's lots of information in there that can get you started.

If you don’t tear down or significantly change your setup, you can usually use the same model for many nights. However, if the model starts to become inaccurate, then you may need to redo it. For example, if the polar alignment changes because of mount settling, or the temperature change is significant enough to measurably change equipment flexure.

BTW, if it is just shifting polar alignment causing an issue, you might try tweaking polar alignment outside of APCC (e.g. via PEMPro, SharpCap, PHD2, polar alignment scope, etc.). Then do a RECAL in APPM, and the model should work well again.


-----Original Message-----
From: [] On Behalf Of
Sent: Saturday, August 7, 2021 6:29 PM
Subject: [ap-gto] APPM Basic questions

Could someone give me a sanity check.

I image with a tear down and set up nightly. I do it from fixed pavers that gives me a fairly good polar alignment
but not precise (tonight I was unusually close about 6' off in each direction once assembled). I then do a polar
alignment with other software to get it good.

Last time out I built a model. I think I'm not supposed to do that when not in a permanent setup, right? And
unliked tPoint there's no "recalibrate" model run, you build from scratch. So if I cannot (or do not want) to build a
model tonight, I should turn off the model corrections, right? (If they don't default to off).

Now tonight it's partly cloudy. I'm building a model but I think probably 1/3 or more of the sky I will get failures. It's
still running.

Let's assume I have a good polar alignment and have done a plate solve and recal from another program
(probably a sync that became a recal).

At what point is it better to use the model as opposed to dispose of it entirely, if clouds are the issue (i.e. and I am
not going to get a better one)? Am I better with nothing, or pretty much anything I can get?

OK... while writing this it finished. 12 failed, 28 good solves, most of the failures in the SE. So... I'm going to load it
just because, but... should I? How good or bad (relative to how much of the sky) is needed before the model does
more good than harm? Or is the answer it ALWAYS does more good than harm to pointing and tracking


PS. I image, I guide, I realize that the model is less relevant to me, but I'm trying to learn good practices for using it,
who knows, might do some unguided imaging at some point.

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