Re: APCC pointing model effects on DEC tracking


Ray Gralak
 

Another question......what kind of problems might i see if i accidently left the pointing model
running during a camera guiding calibration and running of pempro?
That won't be a problem. You don't need to turn off tracking rate correction for autoguider calibration.

-Ray

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of david w pearson via groups.io
Sent: Tuesday, February 23, 2021 7:32 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] APCC pointing model effects on DEC tracking

Thanks Ray! Another question......what kind of problems might i see if i accidently left the pointing model
running during a camera guiding calibration and running of pempro? I think i had a brain fart and forgot to
turn off.
thanks
dave


On Tuesday, February 23, 2021, 06:39:10 PM PST, Ray Gralak <iogroups@...> wrote:


Hi Dave,

The initial dec tracking error is probably just dec backlash runout. Until the backlash is taken up the dec axis
wasn’t moving despite the non-zero dec tracking rate.

Regarding pointing accuracy, try opening APPM and doing a plate solve and recal with APPM. If that doesn’t
help it may be time to create a new model.

-Ray

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of david w pearson via groups.io
Sent: Tuesday, February 23, 2021 2:29 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] APCC pointing model effects on DEC tracking

sorry for confusion......AP1200.
I understand that the APCC pointing model not only improved pointing but helped tracking according to Ray.
I experienced it myself after creating a pointing model.
Since i have an issue that involves APCC pointing model, maxim DL guiding, and AP1200 i need to
understand
APCC part in the process to determine how to resolve. I thought that APCC issues delta mount RA/DEC
commands according to the pointing model.
My question is does these delta RA/DEC commands require a convergence over time or not?
Meaning if the polar alignment error was vastly different from what the pointing models assumes, what
happens and how does APCC and mount behave?
thanks
dave



On Tuesday, February 23, 2021, 10:23:52 AM PST, Roland Christen via groups.io
<chris1011@...> wrote:




The DEC axis tracking error grows up to about 2-3 arc-sec tracking error

The Dec axis doesn't track. There is no tracking in Dec, only the RA axis tracks at sidereal rate. Do you mean
Dec Guiding by any chance?

APCC pointing model does not set custom tracking unless you turn on the custom rate in APPM.

Which mount are we talking about?


Rolando

-----Original Message-----
From: david w pearson via groups.io <p.davidw@...>
To: main@ap-gto.groups.io
Sent: Tue, Feb 23, 2021 11:43 am
Subject: [ap-gto] APCC pointing model effects on DEC tracking



Notice something new with my autoguiding, Maxim DL,APCC pointing model setup upon initial guiding during
startup. thereafter it doesn't happen.
The DEC axis tracking error grows up to about 2-3 arc-sec tracking error before converging back to normal at
0.1 to 0.3 arcsec in about 60 seconds.
During this time, i use an aggressiveness of 10 In maxim DL. Does the APCC pointing model tracking
algorithm try to compensation for DEC tracking
errors, using the pointing model, that would account for the 60 sec tracking error convergence? Also i
have
noticed that my pointing point model probably needs to be redone as
my pointing errors seem to be worse than right after model build. My first impression is my polar alignment
may be further off than the pointing model is assuming?
Any insight that would direct me toward the solution would be appreciated.
thanks
dave

--
Roland Christen
Astro-Physics






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