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Re: #APCC - V1.9 Tracking Error
#APCC
Rouz
Roland,
I'm not entirely sure. The target moves "down" mostly with a 90 degree camera angle. I have solved the 1st and last image of the session. First image Observation start time ... 2021-08-20 09:16:09 UTC Image center ............. RA: 20 11 56.941 Dec: +38 22 33.21 Last image: Observation start time ... 2021-08-20 10:07:53 UTC Image center ............. RA: 20 11 58.590 Dec: +38 22 21.79
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Re: #APCC - V1.9 Tracking Error
#APCC
Bill Long
This is unguided imaging right? If so as a best practice I dial in my PA as close as I can with SharpCap before I build the model. When I was not using encoders I would ensure my PEC curve was solid (~1" or less) using PEMPro and build a new curve if it
was no longer correcting as well. Also switch your balancing to neutral in both axis of you haven't already.
Not saying any of these are the cause, just some things to do if you're trying to image unguided.
From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Rouz <rbidshahri@...>
Sent: Friday, August 20, 2021 1:22 PM To: main@ap-gto.groups.io <main@ap-gto.groups.io> Subject: Re: [ap-gto] #APCC - V1.9 Tracking Error Also, I suspect polar alignment isn't perfect. Could that be the cause.
The model can correct for that right? To what degree. Is that polar az and polar Alt values in the model?
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Re: #APCC - V1.9 Tracking Error
#APCC
Roland Christen
It's not a flex problem, Ray.
Roland
-----Original Message-----
From: Ray Gralak <iogroups@...> To: main@ap-gto.groups.io Sent: Fri, Aug 20, 2021 3:31 pm Subject: Re: [ap-gto] #APCC - V1.9 Tracking Error > I believe its not a flex problem as its very consistent.
It's good that it is consistent, but it is possible that it is unmodeled flexure. The pointing terms best model a solid object with consistent flexure characteristics. When you have a large mirror on one end of the scope the flexure can be uneven as a whole across the scope. That's what the dec-arc tracking is supposed to handle but the path that the hour-angle point creation strategy takes can introduce random flexures that are not there when doing a declination arc. -Ray > -----Original Message----- > From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Rouz > Sent: Friday, August 20, 2021 1:08 PM > To: main@ap-gto.groups.io > Subject: Re: [ap-gto] #APCC - V1.9 Tracking Error > > Here is another blink clip of the previous nights tracking with a model with less points. > > I believe its not a flex problem as its very consistent. > > > https://www.dropbox.com/s/ke6l2foort7jpod/tracking%2018-Aug-21.wmv?dl=0 > > -- Roland Christen Astro-Physics
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Re: #APCC - V1.9 Tracking Error
#APCC
Ray Gralak
I believe its not a flex problem as its very consistent.It's good that it is consistent, but it is possible that it is unmodeled flexure. The pointing terms best model a solid object with consistent flexure characteristics. When you have a large mirror on one end of the scope the flexure can be uneven as a whole across the scope. That's what the dec-arc tracking is supposed to handle but the path that the hour-angle point creation strategy takes can introduce random flexures that are not there when doing a declination arc. -Ray -----Original Message-----
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Re: #APCC - V1.9 Tracking Error
#APCC
Roland Christen
If you can answer my question I could probably tell you what's happening.
Roland
-----Original Message-----
From: Rouz <rbidshahri@...> To: main@ap-gto.groups.io Sent: Fri, Aug 20, 2021 3:22 pm Subject: Re: [ap-gto] #APCC - V1.9 Tracking Error Also, I suspect polar alignment isn't perfect. Could that be the cause.
The model can correct for that right? To what degree. Is that polar az and polar Alt values in the model? -- Roland Christen Astro-Physics
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Re: #APCC - V1.9 Tracking Error
#APCC
Rouz
Also, I suspect polar alignment isn't perfect. Could that be the cause.
The model can correct for that right? To what degree. Is that polar az and polar Alt values in the model?
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Re: Re: #s ZS - V1.9 Tracking Error
Andrea Lucchetti
On Fri, 20 Aug 2021 at 22:17, Rouz <rbidshahri@...> wrote: Ray,
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Re: #APCC - V1.9 Tracking Error
#APCC
Roland Christen
You didn't answer my question. Which axis is showing the error?
Roland
-----Original Message-----
From: Rouz <rbidshahri@...> To: main@ap-gto.groups.io Sent: Fri, Aug 20, 2021 3:17 pm Subject: Re: [ap-gto] #APCC - V1.9 Tracking Error Ray,
Ah, so I shouldn't use "hour angle", I can try that. I tried pointing corrections on and Dec Arc off, seemed better. It looked like Dec arc made it worse but the object still moves. Some subs more than others. -- Roland Christen Astro-Physics
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Re: #APCC - V1.9 Tracking Error
#APCC
Rouz
Ray,
Ah, so I shouldn't use "hour angle", I can try that. I tried pointing corrections on and Dec Arc off, seemed better. It looked like Dec arc made it worse but the object still moves. Some subs more than others.
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Re: #APCC - V1.9 Tracking Error
#APCC
Rouz
Here is another blink clip of the previous nights tracking with a model with less points.
I believe its not a flex problem as its very consistent. https://www.dropbox.com/s/ke6l2foort7jpod/tracking%2018-Aug-21.wmv?dl=0
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Re: #APCC - V1.9 Tracking Error
#APCC
Roland Christen
Can you tell me which way the image drifts, RA or Dec?
Roland
-----Original Message-----
From: Rouz <rbidshahri@...> To: main@ap-gto.groups.io Sent: Fri, Aug 20, 2021 3:02 pm Subject: Re: [ap-gto] #APCC - V1.9 Tracking Error Hi Roland,
My camera orientation is 90 degrees and the image downwards mostly but at a slight diagonal. I have made a short video clip in the folder. https://www.dropbox.com/s/sf8gkmj1ks2c2pu/tracking.wmv?dl=0 Resolution ............... 0.929 arcsec/px
Rotation ................. 90.992 deg
Reference system ......... ICRS
Observation start time ... 2021-08-20 09:29:15 UTC
Observation end time ..... 2021-08-20 09:34:15 UTC
Geodetic coordinates ..... 123 ** 44 W 49 ** 45 N 0 m
Focal distance ........... 1670.25 mm
Pixel size ............... 7.52 um
Field of view ............ 48' 23.0" x 32' 19.1"
Image center ............. RA: 20 11 57.317 Dec: +38 22 29.95
-- Roland Christen Astro-Physics
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Re: #APCC - V1.9 Tracking Error
#APCC
Ray Gralak
Rouz,
toggle quoted messageShow quoted text
Unfortunately, I think the "Hour Angle" point ordering strategy may be the problem. Because the points are not collected in a declination-arc it is way more likely to be subject to random flexure at each declination. Did you try taking any images with all pointing terms enabled but with Declination Arc tracking off? -Ray
-----Original Message-----
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Re: #APCC - V1.9 Tracking Error
#APCC
Rouz
Hi Roland,
My camera orientation is 90 degrees and the image downwards mostly but at a slight diagonal. I have made a short video clip in the folder. https://www.dropbox.com/s/sf8gkmj1ks2c2pu/tracking.wmv?dl=0 Resolution ............... 0.929 arcsec/px Rotation ................. 90.992 deg Reference system ......... ICRS Observation start time ... 2021-08-20 09:29:15 UTC Observation end time ..... 2021-08-20 09:34:15 UTC Geodetic coordinates ..... 123 ** 44 W 49 ** 45 N 0 m Focal distance ........... 1670.25 mm Pixel size ............... 7.52 um Field of view ............ 48' 23.0" x 32' 19.1" Image center ............. RA: 20 11 57.317 Dec: +38 22 29.95
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Re: #APCC - V1.9 Tracking Error
#APCC
Rouz
Hi Ray,
Yes I used "Hour Angle" with APPM. I closed APCC, I'll open it again and see if I can create that zip file now. Thanks, Rouz
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Re: #APCC - V1.9 Tracking Error
#APCC
Roland Christen
The target will move a few hundred pixels over the coarse of the night. Did the target move in RA or Dec?
Roland
-----Original Message-----
From: roozbeh_bid <rbidshahri@...> To: main@ap-gto.groups.io Sent: Fri, Aug 20, 2021 2:10 pm Subject: [ap-gto] #APCC - V1.9 Tracking Error I'm very happy that V1.9 now works with NINA and ASTAP.
Model building was very straightforward and quick. For some reason, my unguided exposures have trailing stars. The target will move a few hundred pixels over the coarse of the night. Using the AP1100CP4, no encoders, CDK12 OTA, pier bolted to concrete floor in a remote dome (backyard). 1700mm focal length, 0.92 arcsec/pixel (bin2) Mechanical: I've double checked every bolt from the concrete to the focuser. The system is very rigid, mirror is bonded to permanent cell. Payload is about 70lbs. I also pointed near zenith to eliminate any potential sag with the same inconsistent results. Periodic Error: Unlikely as the image is constantly moving in on direction. I checked the mount with Pempro last year with a native error of 3" peak to peak. It was about 1" with PEC on. Model: Using NINA and ASTAP with "high precision slews" = on 1st attempt with points every 12 degrees 2nd attempt with very fine 6 degrees apart 184 points (I only have half the sky visible) Environmental sensor, pressure for local weather station. Its using a sensor on the telescope which was reading RH a bit higher (92 to 99%) than the weather station value of 82% Tracking: It seems when I turn Dec-arc tracking on it gets worse. I tied refraction correction on - off. Both on both off Some subs much worse than others, but moves in the same direction generally. Here is a folder with some 300s test subs, log file, appm files. I have named them with dec arc and refraction correction on or off https://www.dropbox.com/sh/80ktuhbtr8btnd9/AAB0FKWeeW9S1S4bp2ZHzMsma?dl=0 Any help would be much appreciated as I've been trying to solve this for days non-stop. Thanks, Rouz -- Roland Christen Astro-Physics
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Re: #APCC - V1.9 Tracking Error
#APCC
Ray Gralak
Hi Rouz,
toggle quoted messageShow quoted text
Thanks for the details! Could you also put a zip file created using the APCC Log zipper utility? Please include all the APCC, APPM, and ASCOM logs from the evening when you were doing the imaging. BTW, I see you are using a dome. When you used APPM did you use the "Hour Angle" strategy for accumulating the data points? -Ray
-----Original Message-----
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#APCC - V1.9 Tracking Error
#APCC
Rouz
I'm very happy that V1.9 now works with NINA and ASTAP.
Model building was very straightforward and quick. For some reason, my unguided exposures have trailing stars. The target will move a few hundred pixels over the coarse of the night. Using the AP1100CP4, no encoders, CDK12 OTA, pier bolted to concrete floor in a remote dome (backyard). 1700mm focal length, 0.92 arcsec/pixel (bin2) Mechanical: I've double checked every bolt from the concrete to the focuser. The system is very rigid, mirror is bonded to permanent cell. Payload is about 70lbs. I also pointed near zenith to eliminate any potential sag with the same inconsistent results. Periodic Error: Unlikely as the image is constantly moving in on direction. I checked the mount with Pempro last year with a native error of 3" peak to peak. It was about 1" with PEC on. Model: Using NINA and ASTAP with "high precision slews" = on 1st attempt with points every 12 degrees 2nd attempt with very fine 6 degrees apart 184 points (I only have half the sky visible) Environmental sensor, pressure for local weather station. Its using a sensor on the telescope which was reading RH a bit higher (92 to 99%) than the weather station value of 82% Tracking: It seems when I turn Dec-arc tracking on it gets worse. I tied refraction correction on - off. Both on both off Some subs much worse than others, but moves in the same direction generally. Here is a folder with some 300s test subs, log file, appm files. I have named them with dec arc and refraction correction on or off https://www.dropbox.com/sh/80ktuhbtr8btnd9/AAB0FKWeeW9S1S4bp2ZHzMsma?dl=0 Any help would be much appreciated as I've been trying to solve this for days non-stop. Thanks, Rouz
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Re: The last couple of weeks are the hardest...
Roland Christen
Any specific recommendations for that, still try for neutral balance, or is it better a bit heavy to one side in wind? Neutral balance.
Rolando
-----Original Message-----
From: ap@... <ap@...> To: main@ap-gto.groups.io <main@ap-gto.groups.io> Sent: Thu, Aug 19, 2021 11:03 pm Subject: Re: [ap-gto] The last couple of weeks are the hardest... Roland wrote:
Well, at least you have a dome. I have to race to move things inside.
But I used to commute for about 20 years off and on to Chicago. Regularly would fly 1200 miles NORTH and end up with it hotter there than where I left. I think I actually liked the winters better (though didn’t have to spend much time
outside).
But you do make up for it in great Steak places and food in general. My clouds seem to have cleared, think I’m going to get my first runs with wind (not a lot, 2-3 gusts 6) and encoders. Wind is main reason I got the AE version. Any specific recommendations for that, still try for neutral balance, or is
it better a bit heavy to one side in wind?
Linwood
-- Roland Christen Astro-Physics
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Re: Dec-Arc Tracking in APCC Pro v1.9 - an explainer please?
Ray Gralak
Each row should have at least five sky data points.If the scope flips to the other pier side, it counts as a new set of two dec arcs of 5+ points (20 total sky points minimum, 10 on each pier side). -Ray -----Original Message-----
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Re: Dec-Arc Tracking in APCC Pro v1.9 - an explainer please?
On Fri, Aug 20, 2021 at 07:11 AM, Ray Gralak wrote:
Each row should have at least five sky data points.Ray, are you talking about at least 5 points to the point where you do a meridian flip or 5 points horizon limit-to-horizon limit including meridian flip? -- Dean Jacobsen Astrobin Image Gallery - https://www.astrobin.com/users/deanjacobsen/
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