ASIAIR Pro plate solving inop

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DJA777
Posts: 6
Joined: Fri Jun 19, 2020 5:02 pm

ASIAIR Pro plate solving inop

Post by DJA777 » Tue Jun 30, 2020 2:52 pm

I just purchased an ASIAIR Pro. Actually a while ago, but received it a month ago due to back order. It has been working well, but a week ago it suddenly stopped plate solving. I have 3 focal length scopes and I know the FL is set right. It stopped working in mid session with nothing changed. It continues to not work on a 1920mm, a 336mm and a 1000mm scope. Other than that, it seems to be fine. I’m out of ideas to deal with this. Any ideas what I can do? I don’t want to return it as it took quite a while to get it.

W7AY
Posts: 236
Joined: Fri Jan 25, 2019 3:38 am
Location: Portland, Oregon, USA

Re: ASIAIR Pro plate solving inop

Post by W7AY » Tue Jun 30, 2020 4:32 pm

If it not a case of wrong focal lengths, the only thing I can think of is that for some reason, the file that contains the database in the microSD card is no longer accessible. Perhaps ZWO has some better guesses.

You might try restoring (into a fresh microSD card) from the backup of the original microSD card that you had made when you took the ASIAIR out of the box. That should force the current ASIAIR app to update the firmware, and any databases.

If it is a matter of bad database file, this should fix it.

Chen

DJA777
Posts: 6
Joined: Fri Jun 19, 2020 5:02 pm

Re: ASIAIR Pro plate solving inop

Post by DJA777 » Tue Jun 30, 2020 6:51 pm

Egg on face. I never made a copy as I don’t have a way to read the mini SD card and I’m lazy. Is there a way to restore the system by downloading it from the internet? I’ll have to get a way to read and write on that little card. Thanks.

DJA777
Posts: 6
Joined: Fri Jun 19, 2020 5:02 pm

Re: ASIAIR Pro plate solving inop

Post by DJA777 » Wed Jul 01, 2020 4:54 pm

I managed to download the OS and copy in my license and get it up and running. No difference. It still won't plate solve anything. There are new features with the firmware upgrade even, but no plate solve. This is critical to the operation of this thing. I must be missing something. Is there more than the imaging camera page where you enter the focal length of the telescope? This all worked beautifully before and I am out of ideas.

W7AY
Posts: 236
Joined: Fri Jan 25, 2019 3:38 am
Location: Portland, Oregon, USA

Re: ASIAIR Pro plate solving inop

Post by W7AY » Wed Jul 01, 2020 7:11 pm

I assume that you have already tried setting focal length to zero, and let the plate solver figure out the plate scale (and thus focal length) by itself?

It takes a little longer to solve with focal length set to zero. If it is successful, ASIAIR will deposit the true focal length into the focal length box in the Camera setup window.

I would also try first with the short OTA and make sure the stars are tack sharp.

Set the camera gain and exposure time so that the plate solver reports between 25 and 100 stars; it seems to be happiest there.

Oh yeah, make sure there is no obstructions at all in the entire plate. The ASIAIR plate solver (or astrometry.net for that matter) don't like shadows of roofs and tree branches sticking into the plate.

Chen

davehudsn
Posts: 3
Joined: Sun Aug 25, 2013 3:14 am

Re: ASIAIR Pro plate solving inop

Post by davehudsn » Wed Jul 01, 2020 7:36 pm

I believe I may know what the problem is. I have been using ASI Air for a long time now, since it first came out.

I recently started having plate solving problems as well. I also just got the ASI AIR PRO and am also having plate solving issues.

What I discovered, is that when the camera is oriented "level on plane" (i.e. if using Alt - Az mount and image appears right side up and proper left right) plate solving fails. If I simply turn the camera about a 1/4 turn, take a picture and plate solve, it works just fine.

My guess is that the camera image "up" is somewhere around 350 to 360 degrees. If I understand plate solving correctly, what it does is try to map the image to know patterns and has to do this for all angles until it gets a match. I think it starts at 0 degrees and goes around clockwise. And being the "up" in the image is around 350-360 degrees, its just taking it too long to get there.

Thats my best guess, but its very repeatable for me.... if plate solve fails, i rotate the camera slightly and then it solves in about 3-5 seconds.

DJA777
Posts: 6
Joined: Fri Jun 19, 2020 5:02 pm

Re: ASIAIR Pro plate solving inop

Post by DJA777 » Wed Jul 01, 2020 10:33 pm

Thanks for those suggestions. I have tried entering 0 for focal length, but that didn't work. The plate solving was amazing before it stopped working. It would solve in sometimes less than a second. Now nothing. I use APT also and that solves, but usually takes about 30 to 40 seconds. I will try rotating the camera tonight. I am using the 336mm focal length - WO GT71 with 0.8 reducer flattener. It finds a ton of stars and solves them quickly. I will try it tonight and see what I get. The frustrating thing is that I can have my target on the field of view, just slightly off center and it will not solve the photo. I will be trying APT plate solving at the same time so see that works OK.

DJA777
Posts: 6
Joined: Fri Jun 19, 2020 5:02 pm

Re: ASIAIR Pro plate solving inop

Post by DJA777 » Wed Jul 01, 2020 10:33 pm

Thanks for those suggestions. I have tried entering 0 for focal length, but that didn't work. The plate solving was amazing before it stopped working. It would solve in sometimes less than a second. Now nothing. I use APT also and that solves, but usually takes about 30 to 40 seconds. I will try rotating the camera tonight. I am using the 336mm focal length - WO GT71 with 0.8 reducer flattener. It finds a ton of stars and solves them quickly. I will try it tonight and see what I get. The frustrating thing is that I can have my target on the field of view, just slightly off center and it will not solve the photo. I will be trying APT plate solving at the same time so see that works OK.

W7AY
Posts: 236
Joined: Fri Jan 25, 2019 3:38 am
Location: Portland, Oregon, USA

Re: ASIAIR Pro plate solving inop

Post by W7AY » Wed Jul 01, 2020 11:50 pm

"My guess is that the camera image "up" is somewhere around 350 to 360 degrees. If I understand plate solving correctly, what it does is try to map the image to know patterns and has to do this for all angles until it gets a match. I think it starts at 0 degrees and goes around clockwise. And being the "up" in the image is around 350-360 degrees, its just taking it too long to get there."

Hi Dave,

That is very interesting! I am purely equatorial and have the long edge of the camera parallel to the constant DEC lines. Never had a problem (yet).

The astrometry.net algorithm does not depend on absolute angles. What it does is to store a database of 4-star asterisms. I have seen 5-star asterism mentioned also, but their white paper showed 4, if memory serves.

What is stored as reference data are the relative distances of a trapezoid that is made by the 4 stars of each asterism. That is how it can handle different plate scales and different camera angles all in one fell swoop. It does not have to rotate the plate to test each angle.

I don't know what ZWO uses for plate solving in ASIAIR. Perhaps, as you described, they actually rotate absolute angles.

Chen
Last edited by W7AY on Thu Jul 02, 2020 12:05 am, edited 1 time in total.

W7AY
Posts: 236
Joined: Fri Jan 25, 2019 3:38 am
Location: Portland, Oregon, USA

Re: ASIAIR Pro plate solving inop

Post by W7AY » Wed Jul 01, 2020 11:59 pm

"The plate solving was amazing before it stopped working."

This is the really puzzling part, especially your original post mentioned it had stopped working in the middle of a session! You didn't rotate the camera back then, did you?

I am curious, does swapping the guide camera for the main camera allow you to plate solve the images from the guide scope?

Chen

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