30 sec delay on align module

rbarberac wrote: s (no, I can't use ASTAP because my guide CCD is very small, with only 960px and ASTAP needs at least 1000px so the alignmen always fails)[/attachment]

The 1000 pixels is not an hard boundary. The reliability for poor image reduces below 1000 pixels but it should still work. Setting the tolerance form 0.005 will 0.007 will help.

Han

han.k wrote:

rbarberac wrote: s (no, I can't use ASTAP because my guide CCD is very small, with only 960px and ASTAP needs at least 1000px so the alignmen always fails)[/attachment]

The 1000 pixels is not an hard boundary. The reliability for poor image reduces below 1000 pixels but it should still work. Setting the tolerance form 0.005 will 0.007 will help.

Han

Good to know! I’ll give it another try

Hi Han,

This night I was able to use ASTAP to solve my images. I need to tweak continuously the exposure, because your algorithm is very sensitive (too much?) to image quality.

Anyway thanks to ASTAP I was able to polar align my AZ GTi mount to 31” from pole!! And refine el each goto landing place. Thanks!

But the problem with Astrometry.net remains, I can’t use it right now

Hello rbarberac,

Exposure time should not be critical. Either 1 or 300 seconds should work. Could you share a few images made with the guider, so I can have a look?

Han

I've uploaded some sample images from the guidescope/CCD combo. As you can see the stars images are very big (chromatic aberration and great IR sensibility)

www.dropbox.com/sh/geasd9s7ardfvg9/AADbz...m9PPwDXAvqzFt1a?dl=0

From tonight, I only have two screenshots . On them you can see how a simple 30º rotation around the pole (I'm in the middle of the polar alignment procedure), makes that ASTAP lost its north (pun indeed)

I have looked to the images. The big stars are not a problem for detection but the number of hot pixels due to the uncooled ASI120. You can see that if you load the images in the ASTAP directly and use the CCD inspector option (in viewer, menu Tools, CCD inspector). Normally one pixel stars are ignored but due to the noise some are seen as stars.

- NGC2175 image solves if I reduce the maximum number of stars to 80 and tolerance to 0.009. This removes the hot pixels
- M33 solves
- NGC281, fails due to oval stars.

The solving will improve a lot if you use a dark. This is an option in ASTAP but rarely used and also a good opportunity to test now.

First make a few darks with about the same exposure time. Or make several e.g 5 of 10 sec, 20 sec, 40 seconds

To set and test this option in ASTAP:

1) Start ASTAP from the education topic menu

2) Load an existing image in ASTAP e.g. NGC 2175_Light_40_secs_001.fits using the viewer menu, FILE, LOAD FITS OR OTHER FORMAT.
3) Open the stack menu CTRL+A and set the red marked options including "Calibrate prior to solving" in the tab ALIGNMENT:



4) Add the darks to the tab DARKS. If you have with more then one exposure time, then activated option classify on DARK EXPOSURE. In this last case the darks should have exactly the same exposure time as an image otherwise they are ignored. If not leave this option unchecked and ASTAP will use any dark.



5) Then hit the SOLVE button in tab alignment or in the viewer. The settings will be saved. Solving should work better now. ASTAP will remember the settings and dark(s) if called from EKOS.

Could you share a dark so I can test it here?

Regards, Han

I'll prepare a set of dark frames for your analysis but I'm unable to reproduce your success. For example, with M33 I've got a failure. After I've limited the analysis to 80 starts and increase the tolerance to 0.009 I'm still failing. I'm using macOS build (the most recent one is 0.9.305a from 2019-12-02)

On the other hand I don't see how can I use dark frames on a live alignment environment, because my CCD has not shutter, so I must put the cap ver the telescope to take darks

Taking dark(s) is easy. Just cap the (guide) telescope and take image(s) of the same exposure as the images you want to solve. Once you set the option "calibrate prior solving" ASTAP will calibrate any image first by subtracting the available dark(s) from the image. Solving will work better for your uncooled ASI120. This will work also when called from EKOS, but test it first in the ASTAP program. The dark subtraction will remove all hot pixels.


You screenshot looks like you have switched on de-bayer by accident. I assume you have mono camera. This de-bayer could spoil solving. In the viewer go to menu TOOLS and uncheck "activate-deactivate auto de-bayer". Or go to settting and activate restore defaults.

The M33 will solve if you activate options "slow" and tolerance 0.007 or 0.009 despite the hot pixels.


Han

Ouch! my fault. I've been working with some RAW files and I let activate the debayer option. When I removed it, I was able to solve M33 as you have said. Thanks a lot for all your help. Next time I'll try to use dark frames!

Happy New Year!

A weeks using ASTAP with random success. Some night it works like a charm and the next one it fails on each frame. Same equipment. Same configuration. Comparable sky quality.

Also in this week, astrometry.net was blocking the align algorithm for this 30” each time I’ve tested... except one night that worked perfectly.

It’s a shame to have a system so powerful, but with such great variance in availability.

Any way, I’m very happy work the Ekos platform in general. What an incredible automation tool. Thanks!

The issue remains. I cant believe that I’m the only one experiencing this odd behavior. What exacerbates the problem is that it has worked two or three nights randomly, so it doesn’t seems an installation problem.


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