Few suggestions for NINA

[Kasra Karimi]

So far loving the version 1.11 of NINA. The HIPS 2 addition is superb. Quite a lot to take in in the Sequencer tab, but it looks exciting. Just a few suggestions for your consideration:

1- In the Imaging tab, it would be nice to be able to change the exposure time without having to pause the imaging first.

2- Time to have an offline image source in the Framing tab that has images? I know it’ll make up a huge file and the maths calculations to get the FoV right is complicated. But it can come handy for those imaging in remote places with no access to internet. The cache option is a good alternative for now.

3- I’m not sure what percentage of NINA users use the PA in NINA. I understand the concept behind the current design and it’s very clever, yet a bit complicated and confusing and certainly not as fast. Implementing a PA routine with live plate solve like SharpCap Pro would be amazing.

[Andrzej Doroszenko]

like SharpCap Pro would be amazing

It is very good idea

[Stefan B]

the main issue is that i don’t understand how the math works for the polar alignment on/near the pole. If you can provide a paper or an in depth explanation, then this could be achieved.

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[Kasra Karimi]

Thank you for replying.

Regarding my first suggestion, I noticed in the 1.11 Nightly #5, now even for the plate solve you have to stop the loop exposure. Before, I could just click on the play button of Plate Solve and it would automatically stop the loop exposure. I know it’s a small thing, but when you’re out at night, cold and tired and short of clear nights, speed is key. (hence my suggestion for the SharpCap-like PA)

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Regarding the math explanation for the PA, I suggest you get in touch with the guy who designed it. He’s very approachable and friendly.

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Tonight I had a proper look at the new sequencer. It’s obvious that a lot of work has gone into it, like A LOT. It’s probably going to take some time to get used to and I understand that the aim is the ultimate automation. It would be good to still have the old way of setting the sequence up (like in 1.10) as an option.

There are so many places and tabs to control one single setting. For example, setting the chip temperature, there are 3 tabs that do that. The confusing bit is that which tab overwrites which.

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[Andrzej Doroszenko]

how the math works for the polar alignment on/near the pole

Maybe it'll help a little: https://www.sharpcap.co.uk/sharpcap/features/polar-alignment

[Tomáš Karabela]

If you can provide a paper or an in depth explanation, then this could be achieved.

As I would love to see a live platesolving feature a la SharpCap in NINA, I set out to figure out the math. By studying source code of PhotoPolarAlign (the script which SharpCap's feature is based on), recording a polar alignment session in SharpCap, and experimenting -- I was finally able to get within 1 arc-minute to SharpCap result using ASTAP and Python code. (It’s difficult to determine the accuracy from just one session, but after hitting many dead ends it seems that it finally “works”.)

@Stefan B , you can find description of the algorithm and my findings here: https://tkarabela.github.io/posts/2021/understanding-photopolaralign.html

Full source code and my polar alignment session data is on GitHub: https://github.com/tkarabela/platesolve-polar-align/blob/master/platesolve-polar-align.ipynb

In my Python implementation I use AstroPy and SciPy libraries. The tricky parts are:

• convert pixel coordinates in platesolved image <-> RA/DEC (J2000)
• convert RA/DEC (J2000) coordinates -> ALT/AZ
• know where the celestial pole is (in RA/DEC J2000, or ALT/AZ coordinates)
• numerically find the minimum of given function (doesn't need to be fancy, the function is nicely behaved)

One tip: look into SharpCap logs when a polar alignment session is running, it has quite a bit more info that it shows in the GUI.

Hope it helps

[Stefan B]

Hi,

thank you for your analysis.

In the meantime i have also made progress and built a three position polar alignment plugin for the advanced sequencer, that is currently being tested. You can find the source code here:
https://bitbucket.org/Isbeorn/nina.plugins/src/master/NINA.Plugin.Notification/NINA.Plugins.PolarAlignment/Instructions/PolarAlignment.cs

I will go through your details and compare it with my approach

[Tomáš Karabela]

Hi, glad this is being worked on :) Looking at your code, it’s quite similar, just the initial finding of the axis is different, and it needs just two images.

[Stefan B]

1 & 3 are available. 2 will be more sophisticated and would be best for a separate issue

[Stefan B]

Removing version: 1.11 Nightly (automated comment)