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INDI Library v2.0.6 is Released (02 Feb 2024)

Bi-monthly release with minor bug fixes and improvements

Strange guiding behaviour

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I’ve never had what I would describe as good guiding. On a good night I would say my guiding is OK. But recently I found my guiding to be horrible. I switched to PhD2 for a little while as that was getting me better results. But last night I tried to use the internal guider again. I was finding the guiding just as poor when using the multistar. So I started to test some of the other algorithms. What I noticed was when I switch to Fast my guiding was good. I did notice that when using Fast I would lose the guide star occasionally. But when it found it again it was not far off and would continue.

So I guess my question is why would I be getting good guiding from one algorithm an absolutely horrible guiding from what everybody else is saying is the best newest way to guide?

My set up is an aVX mount, 50mm Orion guide scope, and an Altair 224mc camera.

Any ideas are appreciated.

Kevin
3 years 1 month ago #67616

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SEP MultiStar is total dependent on star-extraction for its performance. All tracking is based on where stars are detected. The older schemes tend to have their own built-in ad hoc star extraction whereas SEP MultiStar uses the SEP library, as the name indicates, and the internal copy of the SEP library was replaced with StellarSolver at 3.5.0.

So, if I had to guess, I'd say your StellarSolver star-detection guiding parameters (go to: Guide Tab --> Options --> Guide --> SEP Profile --> pencil icon) are not properly matched with your equipment. Alternatively, perhaps an issue in the focal length or other image parameters for your guide scope and camera--look on the guide tab at the 2 lines containing "Focal, Aperture, F/D, FOV" to make sure they make sense.

Hy
3 years 1 month ago #67632

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Replied by S on topic Strange guiding behaviour

Just curious, as I'm also trying to optimize my guiding.
What is "horrible guiding" and what is "good guiding"?
3 years 1 month ago #67636

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Replied by Markku on topic Strange guiding behaviour

I'm curious what you men by "..switch to Fast my guiding was good.." ??
I'm thinking that guiding with less than 1 arcsec error is good guiding otherwise it's pretty good.

Br,
/Markku
3 years 1 month ago #67639

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Replied by Kevin on topic Strange guiding behaviour

Fast is a different algorithm that you can use for guiding. Multi star seems to be the default lately. You can switch it underneath the options. When my guiding is bad it’s in the 2s or worse. Thank Hy, i’ll check those settings out.
3 years 1 month ago #67652

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Replied by S on topic Strange guiding behaviour

My guiding is also a bit above 2" RMS which is the reason why I played with it last night. Adjusting the "proportional" parameter from 133 to 90 got the RMS down to about 1.3" RMS. Also, using bin2 helped. I think my problem might be the star shapes are not very good, so maybe the guidescope is to blame...

Are we supposed to go below 1" or what is a good goal here?
3 years 1 month ago #67653

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Replied by Markku on topic Strange guiding behaviour

Thanks Croz, I have to check that :)
Sometimes I get a good guiding but it seems to depend on if the scope it at West or East, I don't know why ? here is a guiding pic at East from last year and one of the best I ever had.

Br,
/Markku
3 years 1 month ago #67664
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Replied by Kevin on topic Strange guiding behaviour

I don't believe that I changed the settings. But it's possible? Below are my settings.



I'm beginning to think this might be an issue with my guide camera. I notice that the settings are never saved when I restart EKOS and the gain is always set to low. I always increase the gain before I guide.
3 years 1 month ago #67672
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Are you clicking on Save Configuration in the camera's Options tab after you change the gain?
See the image below, 3rd line, click on save.
I know the screenshot is from the simulator (what's convenient to me now)
but your guide camera should have the same Options tab with a Save Configuration button.
[And, yes, that Indi user-interface is not natural for me either, but it's been burned into my brain from many missed configuration changes.]


With regard to the StellarSolver parameters, not sure. You are using the default parameters, which are exactly what I'm using.
Of course, this can depend on your guiding optics and camera.
You might play with max size and min area (e.g. be conservative and increase max-size and reduce min area? but I'm not sure) . Probably you'd be better off not messing with that and making sure your gain was good first.

What I'd do is have guide debugging on and look at the number of stars detected during the problematic guiding, and see if there's a reasonable amount (e.g. under 10 seems too small, it should guide fine with 50, ...). Here's a single guiding iteration from my own log from last night. You can see that on the 7th line it says it detected 28 stars, which is fine. It found the guide star and all 9 reference stars, and had a successful guide update.
[2021-02-21T20:59:43.190 PST DEBG ][     org.kde.kstars.ekos.guide] - Capturing frame...
[2021-02-21T20:59:46.300 PST DEBG ][           org.kde.kstars.indi] - processBLOB() mode  2
[2021-02-21T20:59:46.301 PST DEBG ][           org.kde.kstars.fits] - Reading file buffer ( "1.2 MiB" )
[2021-02-21T20:59:46.492 PST DEBG ][     org.kde.kstars.ekos.guide] - Received guide frame.
[2021-02-21T20:59:46.492 PST DEBG ][     org.kde.kstars.ekos.guide] - Multistar: findTopStars 250
[2021-02-21T20:59:46.493 PST DEBG ][           org.kde.kstars.fits] - Sextract with:  "1-Guide-Default"
[2021-02-21T20:59:46.651 PST DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 28 stars, 0.16s"
[2021-02-21T20:59:46.651 PST DEBG ][     org.kde.kstars.ekos.guide] -  StarCorrespondence found guideStar at  0 found/not 9 0
[2021-02-21T20:59:46.651 PST DEBG ][     org.kde.kstars.ekos.guide] - StarCorrespondence found  0 at 137.454 533.402 SNR 41.927
[2021-02-21T20:59:46.682 PST DEBG ][     org.kde.kstars.ekos.guide] - ################## BEGIN PROCESSING ##################
[2021-02-21T20:59:46.682 PST DEBG ][     org.kde.kstars.ekos.guide] - Star    X :  137.454  Y  :  533.402
[2021-02-21T20:59:46.682 PST DEBG ][     org.kde.kstars.ekos.guide] - Reticle X :  137.452  Y  : 532.75
[2021-02-21T20:59:46.683 PST DEBG ][     org.kde.kstars.ekos.guide] - Star    RA:  180.816  DEC:  701.671
[2021-02-21T20:59:46.683 PST DEBG ][     org.kde.kstars.ekos.guide] - Reticle RA:  180.813  DEC:  700.814
[2021-02-21T20:59:46.683 PST DEBG ][     org.kde.kstars.ekos.guide] - -------> AFTER ROTATION  Diff RA:  -0.528318  DEC:  -0.674598
[2021-02-21T20:59:46.683 PST DEBG ][     org.kde.kstars.ekos.guide] - RA channel ticks:  4  DEC channel ticks:  4
[2021-02-21T20:59:46.683 PST DEBG ][     org.kde.kstars.ekos.guide] - Multistar getDrift, reticle: 137.452 532.75 guidestar 137.569 532.344 so offsets: -0.116821 0.406982
[2021-02-21T20:59:46.683 PST DEBG ][     org.kde.kstars.ekos.guide] - "            #   x      y      flux    HFR  SNR      Ref:    #   x      y      flux    HFR  SNR   dRA   dDEC"
[2021-02-21T20:59:46.683 PST DEBG ][     org.kde.kstars.ekos.guide] - "MultiStar   0  137.5  533.4   3516   2.76  41.9     Ref:    0  137.5  532.8   3864   2.36  44.0 -0.53 -0.67"
[2021-02-21T20:59:46.684 PST DEBG ][     org.kde.kstars.ekos.guide] - "MultiStar   1  252.1  218.9   3077   2.59  39.2     Ref:    1  252.4  218.2   3195   2.29  40.0 -0.82 -0.45"
[2021-02-21T20:59:46.684 PST DEBG ][     org.kde.kstars.ekos.guide] - "MultiStar   2  189.0  639.1   2230   2.38  33.4     Ref:    2  189.1  638.3   2441   2.19  34.9 -0.75 -0.74"
[2021-02-21T20:59:46.684 PST DEBG ][     org.kde.kstars.ekos.guide] - "MultiStar   3 1003.5  830.5   2128   2.09  32.6     Ref:    4 1003.8  830.0   1844   2.38  30.4 -0.70 -0.36"
[2021-02-21T20:59:46.684 PST DEBG ][     org.kde.kstars.ekos.guide] - "MultiStar   4  341.1  630.3   1740   2.17  29.5     Ref:    3  341.3  629.5   1910   2.18  30.9 -0.83 -0.64"
[2021-02-21T20:59:46.684 PST DEBG ][     org.kde.kstars.ekos.guide] - "MultiStar   5  470.4  238.7   1500   2.68  27.4     Ref:    5  470.5  238.0   1536   2.04  27.7 -0.69 -0.67"
[2021-02-21T20:59:46.684 PST DEBG ][     org.kde.kstars.ekos.guide] - "MultiStar   6  378.5  728.1   1099   1.75  23.4     Ref:    8  379.0  727.4    974   2.18  22.1 -0.98 -0.38"
[2021-02-21T20:59:46.685 PST DEBG ][     org.kde.kstars.ekos.guide] - "MultiStar   7  915.2  695.6   1067   1.95  23.1     Ref:    9  915.3  694.9    959   2.30  21.9 -0.68 -0.68"
[2021-02-21T20:59:46.685 PST DEBG ][     org.kde.kstars.ekos.guide] - "MultiStar   8  223.0  627.3   1027   2.01  22.7     Ref:    6  223.1  626.5   1073   2.18  23.2 -0.76 -0.72"
[2021-02-21T20:59:46.685 PST DEBG ][     org.kde.kstars.ekos.guide] - "MultiStar   9    6.5  527.6    882   2.19  21.0     Ref:    7    6.7  526.9    994   2.05  22.3 -0.78 -0.53"
[2021-02-21T20:59:46.685 PST DEBG ][     org.kde.kstars.ekos.guide] - MultiStar: Drift median  -0.754144 -0.656813 10  of  28 #guide 10
[2021-02-21T20:59:46.685 PST DEBG ][     org.kde.kstars.ekos.guide] - -------> MultiStar:      Diff RA:  -0.754144  DEC:  -0.656813
[2021-02-21T20:59:46.685 PST DEBG ][     org.kde.kstars.ekos.guide] - Processing Axes
[2021-02-21T20:59:46.685 PST DEBG ][     org.kde.kstars.ekos.guide] - At # 4 drift[ 0 ][ 4 ] =  -0.754144  , t_delta:  -0.754144
[2021-02-21T20:59:46.685 PST DEBG ][     org.kde.kstars.ekos.guide] - delta         [ 0 ]=  -0.754144
[2021-02-21T20:59:46.686 PST DEBG ][     org.kde.kstars.ekos.guide] - drift_integral[ 0 ]=  0.120476
[2021-02-21T20:59:46.686 PST DEBG ][     org.kde.kstars.ekos.guide] - "GPG::result(in= -0.75,snr= 41.9,ts=  3.00,ppt= -1.0)"
[2021-02-21T20:59:46.690 PST DEBG ][     org.kde.kstars.ekos.guide] - "PPEC rslt: input = -0.75, final = -0.83, react = -0.38, pred = -0.47, hyst = -0.38, hyst_pct =  0.04, period_length = 480.00"
[2021-02-21T20:59:46.690 PST DEBG ][     org.kde.kstars.ekos.guide] - pulse_length  [RA] = 112 Direction     : Increase
[2021-02-21T20:59:46.690 PST DEBG ][     org.kde.kstars.ekos.guide] - "GPG: elapsed 0.004s. RA in -0.754144, result: -0.829838 * 135.556 --> -112.49 : len 112 dir 1"
[2021-02-21T20:59:46.690 PST DEBG ][     org.kde.kstars.ekos.guide] - pulse_length  [ 0 ]=  112
[2021-02-21T20:59:46.691 PST DEBG ][     org.kde.kstars.ekos.guide] - Direction     :  Increase RA
[2021-02-21T20:59:46.691 PST DEBG ][     org.kde.kstars.ekos.guide] - At # 4 drift[ 1 ][ 4 ] =  -0.656813  , t_delta:  -0.656813
[2021-02-21T20:59:46.691 PST DEBG ][     org.kde.kstars.ekos.guide] - delta         [ 1 ]=  -0.656813
[2021-02-21T20:59:46.691 PST DEBG ][     org.kde.kstars.ekos.guide] - drift_integral[ 1 ]=  -0.145953
[2021-02-21T20:59:46.691 PST DEBG ][     org.kde.kstars.ekos.guide] - pulse_length  [ 1 ]=  87
[2021-02-21T20:59:46.691 PST DEBG ][     org.kde.kstars.ekos.guide] - Direction     :  Decrease DEC
[2021-02-21T20:59:46.706 PST DEBG ][     org.kde.kstars.ekos.guide] - ################## FINISH PROCESSING ##################
3 years 1 month ago #67689
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Replied by Kevin on topic Strange guiding behaviour

Yes, I save the config. Interesting that my options are quite different. I guess this depends on the camera itself. But I'd like to control the log level and I don't have those settings to enable.

Not sure if this has anything to do with my bad guiding...

3 years 1 month ago #67701
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The logging options are found by clicking on the left-most main tab, and then the Logs button near the top right




after doing that, this menu comes up






and you can control the logging levels. You can see that I have most Ekos modules being logged, but that's because I'm a developer.

Also, I was showing you the simulator page, because my scope wasn't setup.
Here's what the page looks like for my own guidecam (QHY 5Lii M). Not too different from yours.


3 years 1 month ago #67703
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For future reference: if you click on Individuals -> Error Reporting at the top of this forum then you end up at this page:
www.indilib.org/individuals/logs-howto.html
which explains how to enable and submit debug logs.
3 years 1 month ago #67707

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