Re: APCC - APPM - and ASTAP


ap@CaptivePhotons.com
 

Jack Huerkamp wrote:

 

[tried file images]


Has anyone else been successful in using ASTAP to do plate solving while doing an APPM run?  If so, what did you have to do to get ASTAP to work for you?


There’s two halves to your question, one is about using ASTAP with APPM.  I’ve done that, using NINA as a camera, and it works great, never misses.

 

The other is using file images (e.g. as a simulator).  I tried it with survey images and never got it to work reliably.  I don’t know why – scale (scale changes?, distortion, saturation, stretched vs linear… it just didn’t work.

 

Here are the settings I used last night with NINA that worked beautifully:

 

Camera: Bin 2, duration 3s, full frame (this is an ASI6200MM Pro).  I use these settings for both 540mm on a 4” refractor and 2800mm on a C11.

 

Plate Solve: ASTAP, Max solve 10s, x and Y scale = 1.39 (more on this), scale tolerance 30%, refine = yes, last as hint = yes

 

ASTAP Plate solve settings (on plate solve tab): Number of stars 1000, radius 5, min star size 0, tolerance 0, speed default, downsample default.

 

For the scale, I switched last night from 2800mm to 540mm and forgot to change scale.  It still worked.  My guess is it somehow solved anyway, then adjusted the scale on its own as the ‘refine’ was set.  But you should set the scale (unbinned though).

 

But while it works 100% of the time, I set up and tried NINA’s simulator which uses sky survey, and despite playing around with settings, I never got it to work reliably.  No idea why, decided I didn’t care so long as it worked in real life.  I’d be curious if people do get it to work with the sky survey.

 

Note that on failure it can be set to save the failed image (Setting, Plate solved images, choose failed or all, they go in C:\Users\username\Documents\Astro-Physics\APPM), and you can try running ASTAP manually and see what it does (run it, file, load fits, when it appears hit solve).   If it is not working at all, hit the SIGMA symbol, look under Alignment at the “Star database used” and make sure it is H18.   And/or the error messages may give a hint.

 

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