When does APPC/APPM model become invalid?


 

Hi folks,

this one is probably for Ray - 

under what conditions does an APPM generated pointing model become invalid?


I have been experiencing tracking/guiding issues, and when I turned off tracking corrections, the issues went away. Which leads me to believe i need to re-do APPM

I'm just thinking through what may have caused this, and didn't have a clear picture on what types of conditions would cause this (e.g., re-meshing worm, etc.)

Thanks

Brian 



Brian Valente


Ray Gralak
 

Hi Brian,

As you know, I responded to you offline earlier.

I will take a look at your logs and get back to you.

-Ray

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Brian Valente
Sent: Monday, August 9, 2021 2:19 PM
To: main@ap-gto.groups.io
Subject: [ap-gto] When does APPC/APPM model become invalid?

Hi folks,

this one is probably for Ray -

under what conditions does an APPM generated pointing model become invalid?


I have been experiencing tracking/guiding issues, and when I turned off tracking corrections, the issues went
away. Which leads me to believe i need to re-do APPM

I'm just thinking through what may have caused this, and didn't have a clear picture on what types of conditions
would cause this (e.g., re-meshing worm, etc.)

Thanks


Brian



Brian Valente
portfolio brianvalentephotography.com <http://brianvalentephotography.com>


Chris White
 

I'd be interested in the answer as well.  

My mount is on a tripod in an observatory and I adjusted PA the other night. 

I didn't update my model and guiding remained at around 0.35" RMS error in phd2. 

So it seems that just a small tweak in PA didn't cause any issues. 

I plan to do a grease job on the mount and possible redo the pempro curve. I imagine that these would require a new model but don't really know. 


Roland Christen
 


I plan to do a grease job on the mount and possible redo the pempro curve. I imagine that these would require a new model but don't really know. 
Re-doing a PemPro curve will not affect the model. Modeling cannot compensate for periodic error, it can only compensate for global errors. Think of periodic error as being potholes in the road and modeling as being the self driving software that keeps you going straight or following a slowly curving road. The modeling will not adjust itself for the potholes. That's what PEM correction is for.

Rolando


-----Original Message-----
From: Chris White <chris.white@...>
To: main@ap-gto.groups.io
Sent: Tue, Aug 10, 2021 9:18 am
Subject: Re: [ap-gto] When does APPC/APPM model become invalid?

I'd be interested in the answer as well.  

My mount is on a tripod in an observatory and I adjusted PA the other night. 

I didn't update my model and guiding remained at around 0.35" RMS error in phd2. 

So it seems that just a small tweak in PA didn't cause any issues. 

I plan to do a grease job on the mount and possible redo the pempro curve. I imagine that these would require a new model but don't really know. 

--
Roland Christen
Astro-Physics