critical issue with all sky polar alignment in the Southern Hemisphere

outsideoursphere

I’m based in Australia, and am attempting to polar aligning using the ASPA feature. The process initially works and displays the alignment error, but this alignment error increases almost linearly every time I press refresh to update it. This happens even without touching the mount or tripod at all. It’s as if tracking is disabled, although I’ve confirmed through the ASIAIR that the mount is tracking.

My mount is a Star Adventurer GTI, and I’m in the southern hemisphere. I have attempted to aim towards the north or south of the sky (avoiding the east or west), and I have also ensured that the telescope doesn’t pass the meridian throughout the process. I’m hoping ZWO can chime in and fix this bug for us!

bgastro

outsideoursphere

Hi outsideoursphere , I've the exact same issue as you and i'm also in Australia. I'm using asiair mini & Heq5 pro mount. Its been a known issue for a long time already and i resolved it by downgrading to a much older software version, v1.9.1, and this issue will go away. Also you should point your mount/scope to the south since we're in southern hemisphere

There's a long thread discussing on this (since DEC 2022), you can read it all here
https://bbs.zwoastro.com/d/15513-polar-alignment-error-increasing-by-itself-at-somewhat-constant-rate/69

RKUzjEdJ

@bgastro How are you dealing with this issue now? Also in Australia, new user and have never got polar alignment to work. I need ASPA as I don’t have a clear southern view. Every article i have read about rolling back does not work or is expired for iOS. I’ve looked at NINA, but it looked intimidating for a newbie in the hobby who has yet to take a single photo, but I might not have a choice by the looks of things.

Corsair

RKUzjEdJ Have a look at Cuiv's channel over on YouTube.

Here's a link to one of his more recent videos on NINA: https://youtu.be/xFPDHl3SDnw?si=SpEWC54TqSN5Geux

bgastro

RKUzjEdJ

hey RKUzjEdJ ,the issue was not really resolved but what I did was to downgrade to v1.9.1 and once I did that everything worked, i've since had many sessions and never had an issue with polar alignment. I'm happy to stick to v1.9.1 as long as its not giving me any issues, its just too risky to move up to the newer versions.

lucasdanda

bgastro

Dear bgastro, it seems like we're alone in this sea. Now, have you been able to use the ASIAir mini features, such as live stacking, with the 1.9.1 software/firmware? Any updates as of 2026?

Thanks for the feedbacks!

AdrianW

I'm also in Australia and have the same issue.
It seems someone at ZWO forgot there are people living south of the Equator.
The problem was solved by buying a mini computer and using Three Point Polar Align in NINA.

bgastro

lucasdanda

Hi @lucasdanda , i don't use live stacking feature, so i can't comment on this.

PMTeam@ZWO

Hello, we've been aware of this issue for some time but haven't been able to reproduce it internally.

To help us investigate more effectively, could anyone who encounters this problem please upload the relevant logs? Additionally, it would be very helpful if you could attach a photo of your setup showing the mount's initial pointing position.

Thank you in advance for your support!

Luxo

PMTeam@ZWO
Simple - ASIAir all-sky polar alignment does not work in the southern hemisphere - the maths is messed up.
I tried it and it wants to post the scope the wrong way - the azimuth and altitude corrections are all wrong.
The original PA method works fine.

Ill do some screenshots tonight from version 2.5.

Could you please test your software - properly.

AdrianW

PMTeam@ZWO . One thing you should look at is the fact that the rotation of the Earth is counter clockwise in the northern hemisphere and clockwise in the southern hemisphere.
This difference may be allowed for in the ASPA program for the north because it seems to be biased toward the northern hemisphere.
When I try to use it it's virtually impossible to use ASPA when pointed to the north because it seems that if I don't readjust the RA quick enough - for instance to the left - the target I'm using has drifted to the right to follow the rotation because it doesn't seem to be tracking or guiding and allowing for a clockwise rotation.
This may be the answer as to why - if adjusting Dec - the Ra error seem to get bigger.

Mario851

PMTeam@ZWO his is a long-standing issue that has been reported multiple times. I am more than willing to provide the system logs to help investigate this—please let me know the exact steps to generate and send them to your team.
Currently, my workaround is to run the ASPA (All-Sky Polar Alignment) routine several times. Because the first reading is accurate, I run an ASPA, adjust the RA and DEC manually, then run a second ASPA to verify the correction, and repeat as needed. It's a very tedious and time-consuming process, but it is the only viable workaround to stay within the ASIAIR ecosystem.

I uploaded the log just a few minutes ago. It shows that in my last ASPA, the error was initially down to 4 arcseconds, but without touching any axis at all, the RA and DEC begin increasing at a constant rate

Luxo

Well well.. tried all-sky polar align tonight and it worked.

Set up the scope
used the mount handset to do 1-star alignment on Sirius to get the azimuth close to correct.
-set to park position (Dec -90 and counterweight down),
connected ASIAir, focused on Octans.
slewed of to some random patch of sky approx 10 degrees west of the SCP and started PA.

Was a at a site near home so sent a log in. Scope was mak Newtonian 900mm focal length f/5 with ASI2600MC DUO.

From memory the other time I tried the scope was much further from the pole - maybe 30 degrees. That failed.

bgastro

AdrianW

When I try to use it it's virtually impossible to use ASPA when pointed to the north because it seems that if I don't readjust the RA quick enough

Hi @AdrianW, are you in Australia / Southern hemisphere? If so just wondering why you said you're pointed to the North?

TheGap50

Like many others in the Southern Hemisphere, living in Brisbane, and having recently purchased a ASI 2600mc Pro. I find myself like many other unable to use the Polar Alignment app. Like others have stated when you finish the initial polar alignment and hit the refresh button to try and improve the alignement the alignment progressively gets worse. I'm near the point of selling all my ZWO cameras and Asi Air equipment and buying QHYCCD cameras and going back to NINA. At least their polar alignment software works. Maybe ZWO should look at the source code for the Nina PA progam and rewiite something for SH customers.

shamrock

Mario851

I do the same .. it is, as you say, tedious but it does work.

Corsair

Mario851
So hang on - are you saying you:

Start the ASPA routine and tap through until you get to the screen that shows how far off your in RA and DEC (assuming you have the Refresh set to be done manually as well rather than auto).
Make adjustments to RA and DEC
Stop the ASPA routine
Home the mount.
Start the ASPA routine again to then see what the RA and DEC error is now.
Repeat until total error low enough.

Mario851

@PMTeam@ZWO Any updates on this issue? I uploaded the logs on March 17th. Thanks."

shamrock

Corsair

Yes, that’s what I do, until I get the smiley face; and I’ve had hours of good tracking after doing that.
As others have commented, it shows that the first reported deviations are reality; when you click ‘refresh’, the reported deviations are spurious.

Though it could be that ZWO have very recently tried something to fix the problem.

My experience had been similar to others – on first ‘refresh’ without any physical adjustment to the mount, the polar deviation values were different from those after ‘calculate’; on each subsequent ‘refresh’, the deviation values seemed to get progressively larger.

However the other night, I noticed a change in the pattern. The different deviation values (around 2 degrees in this case) still occurred after the initial ‘refresh’; but on each subsequent ‘refresh’, the values remained quite close (within around 2 arc minutes) to those initial values – and this margin is probably to be expected given that the ASPA methodology is an approximation (ie mathematically imperfect).
The attached screenshots show the base ‘calculate’ values, the initial ‘refresh’, and some subsequent ‘refreshes’.

Unfortunately, the clouds rolled in at that point, so my ad hoc testing was cut short.
I have designed a set of test scenarios to better identify the pattern.
Hopefully the skies will be clear on Saturday night.

Mario851

Corsair That is correct, the first drift reading provided by 'ASPA' is always correct; it's just that as it updates, it starts to deviate. That’s why you run an 'ASPA', adjust the axes, and then start a fresh 'ASPA' from the beginning to verify the correction, repeating the process as needed. I’ve been using this method for a year now, often achieving guiding below 0.5" RMS. It’s tedious, but it’s the only way that works without leaving the ASIAIR ecosystem

Corsair

Mario851

Wow. That's nuts.

shamrock

I do hope they have done something to rectify it

Luxo

Mario851

What sort of declination are the stars you're using for ASPA ?

I tried ASPA out of curiosity around Xmas after slewing the scope to some random place around dec -70 and it seemed to work. I then set the scope to PARK and ran a normal PA to see what the difference was - the ASPA was several arc minutes off compared to where the PA routine put the scope.

It left me thinking ASPA is OK for those with scopes under 1000mm focal length - the field rotation will not be noticeable at their image scale, but I doubt its a good idea with my beast at 3000mm and 0.25 arcsec/pixel.