M15 Problem solving at FL 1645
Stacking program, astrometric (plate) solver, fits file viewer
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han59
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M15
Image generated vis SGP. I also use a rotater. This is on a C92.5 using a 0.7 FR.
Is this is a problem with too many or too few stars?
Hello Matt,
This is an interesting image for a further investigation. Somehow it doesn't solve. At the moment I don't know why.
Han
The image can be easilly solved if you set the option "slow". I suspect it is caused by the fact that the Gaia database has much more stars from M15 then you can image with an Earth based telescope. This is causing an unbalance resulting in different quad patterns.
I have to look into this more. Your are not the first to report this problem and having a setup with relative small field of view.
To set checkmark "slow", open ASTAP, press CTRL+A and go to tab Alignment. The press CTRL+
END to save at leave the program (or viewer FILE, EXIT (and save settings))
See attched screenshot.
Han
Last edit: han.k 2020-09-27
TY will try that on next available night. ASTAP mostly works well and fast; however, sometimes like this cluster it fails for some reason - and it takes a long time to fail. Would it be possible to add in some option that limits the amount of time ASTAP will try to solve? I would probably set it for 30 sec. and then let my failover solver kick-in.
The best way to limit it is to reduce the search area. So maybe 10 degrees instead of 30 degrees. In SGP this is translated from the number or regions. You can set this under Equipement Profile manager, Plate Solve. Set it at something like 400 regions for a radius of around 10 degrees.
I'm working on a better fix which seems to work. I will have a test version tomorrow. If you could get for me some more images of global clusters that would be nice for testing.
Han
M15 - not sure the FL in the Fits is accurate - it says 2350, but it's likely 1645.
A better M15
Sadly, that's all I have. Thought I had M14 but can't find it.
I found the thread over on the SGP forums:
https://forum.sequencegeneratorpro.com/t/astap-and-ps2-in-the-region-of-m13/13298/10
where you discuss this. I posted a request over there to supply more images.
Hello Matt,
Thanks for the images. All images solve now reliable in version 0.9.422 just released. It is only available from here:
http://www.hnsky.org/astap_setup.exe
This was a major overhaul of the solver. I tried several approaches and found one which works well. You can now switch off the option "slow"
I have considered updating the database and remove the global cluster center stars but the problem is wide spread. Now ASTAP ignores detected database quads with dimensions smaller then found in the image. The solving speed look a little better due to an improved program flow.
I you have time test it on some clusters and if have an image where it still fails, please share it.
Clear skies, Han
More adjustments where made and ASTAP 0.9.423 is now released on Sourceforge. This version seems to work better with global cluster images extracted from the Deep-Sky-Survey images then PS2.
M3 DSS image which can be solved by ASTAP and not by PS2:
http://nova.astrometry.net/user_images/4035345#annotated
nova.astrometry.net is unbeatable in reliability. If I crop this image further, ASTAP will fail and nova.astrometry.net not, but it is only 12.8 x 11.4 arcmin and 759 x 676 pixels so I´m happy with the performance.
Clear skies, Han
Han - thanks for the update. I havent' had the opportunity to test anything due to clouds and equipment issues.