#1  
Old 30-04-2022, 08:34 PM
Craig_
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ASI Air Plus P.A routine

I got my gear out tonight for first time in months (which was a mistake in hindsight as it was an incredibly damp night) and tonight was my first night to use the ASI Air Plus I got last November (!). Bloody cloud. Anyway, I really struggled with the polar alignment routine.

I have historically always used Sharpcap's polar alignment routine and never had any issues with it. Always able to dial in P.A with incredible accuracy very quickly. Tonight I did the usual - put the tripod down, level it, make sure it's pointing true south, etc. Boot up the ASI Air, at first P.A seems to work OK - it platesolves the initial image, adjusts by 60 degrees and platesolves again, and reports my error to the SCP. All OK so far. But then it just went off the rails after that.

It would tell me, for example, I had 10 degrees 14 minutes 27 seconds error on the azimuth and say 25 minutes 10 seconds error on the alt (these are just rough numbers but are approximately what it was reporting.) I would dial in a small adjustment in the direction it was telling me to, platesolve again and see the error improve - great. But pretty quickly I got to a point where continuing to dial in corrections on alt/az broke platesolving - as though I'd overcorrected - even though it was still telling me to keep correcting in a particular direction prior to it breaking. I was only making small adjustments; I am no newbie to polar alignment having done it in sharpcap countless times. I later figured out that I had to make say a small adjustment on alt, then a small adjustment on az, then alt, then az, etc, and that worked for a while, and then despite still reporting ~8 degrees of total error, got to a point where continuing to make even tiny adjustments on either axis in the directions it was telling me to just broke platesolving.

Any clues what I was doing wrong? At face value it seems to work much the same way as Sharpcap, except in SC I like that you get a continuously updated feed of what you have captured for each PS on screen and it includes arrows showing where you are relative to the SCP - it makes it very hard to go in the wrong direction or overcorrect dramatically. As far as I can tell ASI Air does not offer an ability to actually live view your platesolved images and just shows where you are relative to the SCP on a x/y axis.

If the night hadn't been so unbelievably wet I'd have plugged my laptop in and PS'ed the old fashioned way but I packed up as my gear was already drenched by 7pm. But I'd like to understand where I went wrong with the ASI Air for next time, as aside from this PA snafu it seems like a really impressive device.
Cheers
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  #2  
Old 30-04-2022, 09:22 PM
RyanJones
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Hi Craig,

I use the ASIair PA routine and always find it really easy. I can probably help but it would help if you explain what you mean by ď broke ď plate solving. Also the error youíre reporting of 8 degrees seems extreme. Was that minutes ? There is a option to do a continuous loop which isnít live view but means you donít have to press the button each time you make a correction. It still works on the crosshair though.

Cheers

Ryan
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  #3  
Old 01-05-2022, 12:54 AM
Craig_
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Quote:
Originally Posted by RyanJones View Post
Hi Craig,

I use the ASIair PA routine and always find it really easy. I can probably help but it would help if you explain what you mean by ď broke ď plate solving. Also the error youíre reporting of 8 degrees seems extreme. Was that minutes ? There is a option to do a continuous loop which isnít live view but means you donít have to press the button each time you make a correction. It still works on the crosshair though.

Cheers

Ryan
Hi Ryan, by broke I mean platesolving would just stop working. It picked up my location fine initially and immediately after it does the RA axis rotation but after I started dialing in corrections it became really intermittent. Pretty sure it was reporting error in degrees, which I agree seems extreme. It ďseemedĒ to know where I was - sometimes - in relation to the SCP but failed to get me there.
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Old 01-05-2022, 07:30 AM
RyanJones
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Itís possible that if it is reporting correctly and you are degrees away that itís confusing the plate solving ? That is a guess though. One of the things that I have had happen to me that confuse ASIair platesolving is if your focus is too far off. It doesnít have to be heaps either. It can platesolve one minute then refuse to the next. Iíd possibly check those two first and see how you go. Another possibly silly one is if you have ambient light nearby. Iíve had plate solving behave erratically when my kitchen light has been on nearby.

Hope this helps

Ryan
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  #5  
Old 01-05-2022, 10:40 AM
JA
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Battery or power supply issue perhaps? Also I'm not sure if it's the ASI air that does it, but as you get closer to perfect alignment with the pole the reticle scale changes and could give the appearance of being further from the pole based on the graphical image shown on the screen. The numerical values should however, show improvement.

Still waiting to use my ASI airs some day.

Best
JA
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Old 01-05-2022, 01:27 PM
Dave882 (David)
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I agree with Ryanís suggestions. Iíve been using the ASIAIR PA routine in various mounts for a couple years and never been too far away for it to work (sometimes Iíve been so far in my setup Iíve had to drag the tripod legs and it still followed me ok).

However I will say that platesolving will start to get problematic for me if
1) ASIAIR expects you to be in one particular position and you are a long way from it due to poor GOTO alignment (but this has never bothered the PA platesolves in my experience)
2) the inputted FL is off
3) mount tracking is turned off (happens sometimes if GOTO home)
4) external influence affecting seeing (cloud/light)
5) very long FL and/or small sensor giving small fov
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  #7  
Old 02-05-2022, 10:41 AM
Craig_
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Quote:
Originally Posted by RyanJones View Post
Itís possible that if it is reporting correctly and you are degrees away that itís confusing the plate solving ? That is a guess though. One of the things that I have had happen to me that confuse ASIair platesolving is if your focus is too far off. It doesnít have to be heaps either. It can platesolve one minute then refuse to the next. Iíd possibly check those two first and see how you go. Another possibly silly one is if you have ambient light nearby. Iíve had plate solving behave erratically when my kitchen light has been on nearby.

Hope this helps

Ryan
Thanks Ryan. Focus should have been fairly close, but possibly the issue as I had not run the AF routine yet (just wracked the focuser out to the approx focus position.) Next clear night I'll check that out.

Quote:
Originally Posted by JA View Post
Battery or power supply issue perhaps? Also I'm not sure if it's the ASI air that does it, but as you get closer to perfect alignment with the pole the reticle scale changes and could give the appearance of being further from the pole based on the graphical image shown on the screen. The numerical values should however, show improvement.

Still waiting to use my ASI airs some day.

Best
JA
Thanks, I doubt it was a power issue, the symptoms don't match what I'd expect to see from such a problem. The numerical values did change (for the better) for a while whilst correcting but then I did eventually reach a point where they did not improve at all and any further tweaks broke the PS routine.

Quote:
Originally Posted by Dave882 View Post
I agree with Ryanís suggestions. Iíve been using the ASIAIR PA routine in various mounts for a couple years and never been too far away for it to work (sometimes Iíve been so far in my setup Iíve had to drag the tripod legs and it still followed me ok).

However I will say that platesolving will start to get problematic for me if
1) ASIAIR expects you to be in one particular position and you are a long way from it due to poor GOTO alignment (but this has never bothered the PA platesolves in my experience)
2) the inputted FL is off
3) mount tracking is turned off (happens sometimes if GOTO home)
4) external influence affecting seeing (cloud/light)
5) very long FL and/or small sensor giving small fov
Thanks. For your points:
1) Sharpcap is similar in that if you're too far off where it expects to be it won't PS, I think for that it is 15 degrees from the pole if not mistaken. For non PA platesolving, yes if there is a significant misalignment to where the software thinks the mount is pointing you will get issues unless you blind solve.
2) I checked this, it was correct although ASIAir did keep changing it slightly (eg I input 840, it changed to 861) I assume this was based on the PS results.
3) Tracking isn't active for polar alignment but yes would definitely impact for other PS.
4) It was a very humid/damp night where I was imaging, possibly a factor. No condensation on the objective though.
5) 840mm with a 1" sensor, not too long I'd have thought.
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  #8  
Old 02-05-2022, 02:35 PM
AdamJL
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The ASI PA model (current one) is based off the NINA plugin (in fact, they took the entire code and copied it), and yes, you can chase PA sometimes with NINA as well with their three point polar aligning. I usually put it down to seeing conditions.
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  #9  
Old 02-05-2022, 03:24 PM
Craig_
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Worst case I will just plug my laptop in first and run PA over Sharpcap via a guide scope (this isn't connected in to the ASIAIR as I use OAG for actual guiding), then I can ignore the ASIAir routine if it continues to give me grief.
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  #10  
Old 03-05-2022, 01:00 AM
Hemi
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Hi Craig,

Did you enable the experimental PA routine? Itís under experimental features tab in the asi air app. It allows PA pretty much anywhere in the sky. Ie it does not need a view of the SCP. It works for me.

Hemi
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  #11  
Old 04-05-2022, 12:38 PM
Craig_
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Originally Posted by Hemi View Post
Hi Craig,

Did you enable the experimental PA routine? Itís under experimental features tab in the asi air app. It allows PA pretty much anywhere in the sky. Ie it does not need a view of the SCP. It works for me.

Hemi
I didn't (not that I was aware of anyway.)

I may have identified the issue. Last night I hooked up my laptop to polar align with Sharpcap first, and had massive issues with that too. In fact the symptoms were almost identical to those I had with the ASI Air - it would just keep sending me on a wild goose chase of corrections before eventually failing to platesolve at all.

After 20 minutes or so I realised that my laptop clock had reset to 2AM in October 2021 for some reason (rather than ~7PM in May). I fixed this and magic - quickly polar aligned to ~10sec of error.

Now, my ASIAir operates completely independently of the laptop. I never saw an option to configure the timezone and assumed it would just use the location of the linked iOS device to determine this, but perhaps not? Is this a setting I need to change?
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Old 04-05-2022, 06:14 PM
foc (Ross)
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Hope your issues are now solved Craig. In case not7, I mention that the main problem I have had with ASIAIR during PA., appears to be due to part of the field being obstructed by urban lit tree branches and leaves. I get through the initial plate solve and rotations but then it will not plate solve at the position correction step.

I should trial the ASIAIRPRO All sky routine then, but I usually fall back on my well remembered polemaster method.

Apart from that and not PA related, only daylight savings gives me issues with this device.
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