Re: APPM plate solve failure and then APCC stopping working

Ray Gralak

Hi Jian


Failed plate solves are a problem with the settings you are using, not APPM. APPM just instantiates the selected plate solver.


Some ways to handle plate solving problems:


·         Take the time to more accurately polar align your mount to within a couple arc-minutes of the pole.

·         Use full-frame images unbinned images (if you are not already)

·         Increase the Max Solve Time

·         Enable the “Try All-Sky plate solving if available” option.

·         Increase the image scale tolerance if you don’t know your image scale accurately.

·         Set the option to update image scale from next plate solve.

·         And very importantly, enable the “Use last plate solve’s offset as hint for next plate solve”.


Here’s a screenshot of how you might setup some of those settings in APPM:



-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 jypeng@...

> Sent: Thursday, June 11, 2020 3:52 PM

> To:

> Subject: [ap-gto] APPM plate solve failure and then APCC stopping working


> Hi Ray,

> I had tried to run APPM twice on June 8 and 10 with a clear sky. I got the same problems in the following steps.

> 1. Started APPM after Horizon and Meridian setup, and camera used SGPro, and selected Small Map Default.

> 2. APPM was able to solve the first two points and then always failed after the third point. See attached image 1.

> 3. So, I stopped the APPM at the fourth point and went to SGPro to plate solve the image. See attached image 2.

>    It seemed SGPro's image was pointing in the right direction.

> 4. Since APPM consistently failed to plate solve after the first two points, so I unchecked "Precess J2000 to JNow"

> and run again.

>   See image 3. Then APPM completes run without any failure.

> 5. However, If I enable Tracking/Pointing Correction in the Pointing Model, then the APCC application stops working.

>     The mount slew to park 3 after a timeout when APCC is no response anymore.

>     if I don't enable the pointing model, and APCC pro works fine,

> Could you help me to identify my problems? I guess that I should not uncheck Precess J2000 to JNow.

> I uploaded the June 10 log file to the following link



> Thanks,

> Jian Yuan Peng


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