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INDI Library v1.9.3 Released (11 Nov 2021)

Bimonthly Stable INDI Library release introduces new drivers and fixes for existing ones. Some highlights:

Polar Alignment Assistant Tool and platsolve - part of view is blocked at Polaris, will it work?

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Hi Everyone,

I've setup my ASI 178 with a CCTV lens (50mm) and the FOV is 510 arcmin * 343.2 arcmin
I'm attempting to use the polar alignment assistant tool and knowing that it requires platesolve to work.
At my observing site (which is a remote site) there're trees blocking part of the view (see picture attached).

So my question is that if part of the view is blocked, would this affect the platesolve?

Stephen

Last edit: 6 months 3 weeks ago by Stephen Wong.
6 months 3 weeks ago #71140
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Starting with KStars 3.5.2, polar alignment works in any part of the sky.  You just need a stretch of clear sky.

For details, please see this post:
indilib.org/forum/general/8602-new-polar...me-and-features.html

So, for example, you could slew to just west of the Meridian a bit above Polaris, and set it to slew west at 30-degrees per slew. Start high enough so 2 slews of 30-degrees West in DEC would stay above the trees. Then click Start. If for some reason you didn't have those 60-degrees of unobstructed sky, you could set it to slew 20-degrees instead, and it would likely work fine.

Hy
Orion Atlas Pro, William Optics ZS105, Moonlight V2 focuser, GSO RC10 w/RSF focuser
ZWO ASI1600, Astronomik Filters, ST80, QHY 5L-IIm guidecam.
KStars/Ekos/Indi on NUC10 & RPi4 w/SSD -- Ubuntu
Projects: Terrain, Polar Align, Analyze, Linear Focuser, SEP MultiStar & GPG Guide, FITS autostretch.
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6 months 3 weeks ago #71141

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I do not see the Polaris and I can only see South and West.
I start tre procedure near the meridian at about -20 of DEC and I move of 20degree.
I make some adjustment of altitude and azimuth, than i come back changing the slew to EAST, to check again the error that is not equal.

I noticed that if do not made nothing and just measure the error when I start from South and slew to West and return to South, the error measured at West is greather than the one measured at South.

Do you have an explaintion regards this differences?
6 months 3 weeks ago #71150

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There is certainly significant noise is these estimates due to many of the different components (hardware and software) in the system. I would not expect (and do not experience myself) exactly the same numbers when repeating measurements like that. I do tend to get similar results, e.g. within an arc-minute or so.
Orion Atlas Pro, William Optics ZS105, Moonlight V2 focuser, GSO RC10 w/RSF focuser
ZWO ASI1600, Astronomik Filters, ST80, QHY 5L-IIm guidecam.
KStars/Ekos/Indi on NUC10 & RPi4 w/SSD -- Ubuntu
Projects: Terrain, Polar Align, Analyze, Linear Focuser, SEP MultiStar & GPG Guide, FITS autostretch.
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6 months 3 weeks ago #71178

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So I'd look at arc-min accuracy with the polar alignment assistant tool. Then for a more accurate alignment then I'll go to the drift tool.

Another question is that would Ekos consider to support additional camera (i.e. 3rd camera) in the equipment profile.
What I have is a rainbowastro mount, and there're no optical polarscope.

And I made myself a DIY "polemaster" like setup, which is an ASI 178 camera with a 50mm CCTV lens, mounting with the polemaster adapter locked rainbowastro mount body, and attempting to use Ekos polar alignment assistance.
I'm using OAG to guide - the OAG mounted to the main scope and will be too narrow for the polar alignment assistance to pickup at the platesolve.
So there're 3 cameras operating at the same time: the one used for polar alignment, the guide cam at the OAG and the main CCD.

What I'm doing now is to connect to different profiles: First I connect to a profile where the ASI 178 as the guidecam with the 50mm lens, and do the polar alignment.
After the polar alignment is done I will have to disconnect, and switch the equipment profile for guiding and imaging. This would work, but is a little time-consuming.
 
6 months 1 week ago #71663

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I get away with only one profile for 3 cameras, main, guide, and PoleMaster (auxiliary device). The main and guide (through OAG) cameras use the main telescope info (f.l. and aperture), and I have set the guide telescope info with the PoleMaster lens specs. So, when I perform the PA, I specify the PoleMaster as the camera to use, and the 'guide' scope, as the optics to use.

When the PA is done, I revert back to main camera and guide camera, through 'main' scope.

Works nicely.

In your situation, your ASI178 could be the auxiliary camera and the 50mm lens, your 'guider' optics.

Hope this helps.
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6 months 1 week ago #71664

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Thank you. Didn't realize camera can be an auxiliary device. I set up the camera and it works! Thanks again!
6 months 4 days ago #71765

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Trying to answer my own question.
I don't have access to the real northern sky, but I have done an experiment by using a tablet as the sky by opening SkySafari on it and let my mount takes images of the screen 

I blocked the screen for like around 40% and EKOS platesolve works effectively. I've pushed it and found if I covered more than half of the FOV then the platesolve will fail.
So if the FOV not block more than 40% I think it's fine.
 
6 months 9 hours ago #71972
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