I too have experienced issues with plate solving. For my setup, I have indilib version 2.0.3 Code v1.8.2-1422-gce3be2ed2. Protocol 1.7 with Kstars version 3.6.7 beta. I have attached the EKOS Align log entries below - I don't think there is much there though:

[2023-08-25T21:20:42.174 CDT INFO ][ org.kde.kstars.indi] - iOptron CEM60 : "[INFO] Slewing to RA: 19:51:57 - DEC: 8:55:53 "
[2023-08-25T21:20:44.512 CDT INFO ][ org.kde.kstars.indi] - iOptron CEM60 : "[INFO] Slew complete, tracking... "
[2023-08-25T21:20:56.131 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "In Progress"
[2023-08-25T21:20:56.132 CDT INFO ][ org.kde.kstars.ekos.align] - "Capturing image..."
[2023-08-25T21:21:04.261 CDT INFO ][ org.kde.kstars.indi] - QHY CCD QHY163M-7fe6e24 : "[INFO] Exposure done, downloading image... "
[2023-08-25T21:21:05.832 CDT INFO ][ org.kde.kstars.ekos.align] - "Image received."
[2023-08-25T21:21:06.030 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "In Progress"
[2023-08-25T21:22:09.770 CDT INFO ][ org.kde.kstars.ekos.align] - "Solver aborted after 63.74 seconds."
[2023-08-25T21:22:09.770 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "Aborted"
[2023-08-25T21:22:17.250 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "In Progress"
[2023-08-25T21:22:17.252 CDT INFO ][ org.kde.kstars.ekos.align] - "Capturing image..."
[2023-08-25T21:22:25.382 CDT INFO ][ org.kde.kstars.indi] - QHY CCD QHY163M-7fe6e24 : "[INFO] Exposure done, downloading image... "
[2023-08-25T21:22:26.838 CDT INFO ][ org.kde.kstars.ekos.align] - "Image received."
[2023-08-25T21:22:27.081 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "In Progress"
[2023-08-25T21:24:08.377 CDT INFO ][ org.kde.kstars.ekos.align] - "Solver aborted after 101.30 seconds."
[2023-08-25T21:24:08.377 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "Aborted"
[2023-08-25T21:24:13.577 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "In Progress"
[2023-08-25T21:24:13.578 CDT INFO ][ org.kde.kstars.ekos.align] - "Capturing image..."
[2023-08-25T21:24:21.710 CDT INFO ][ org.kde.kstars.indi] - QHY CCD QHY163M-7fe6e24 : "[INFO] Exposure done, downloading image... "
[2023-08-25T21:24:23.116 CDT INFO ][ org.kde.kstars.ekos.align] - "Image received."
[2023-08-25T21:24:23.314 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "In Progress"
[2023-08-25T21:28:47.342 CDT INFO ][ org.kde.kstars.ekos.align] - "Solver aborted after 264.03 seconds."
[2023-08-25T21:28:47.343 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "Aborted"
[2023-08-25T21:28:55.599 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "In Progress"
[2023-08-25T21:28:55.600 CDT INFO ][ org.kde.kstars.ekos.align] - "Capturing image..."
[2023-08-25T21:29:03.731 CDT INFO ][ org.kde.kstars.indi] - QHY CCD QHY163M-7fe6e24 : "[INFO] Exposure done, downloading image... "
[2023-08-25T21:29:05.148 CDT INFO ][ org.kde.kstars.ekos.align] - "Image received."
[2023-08-25T21:29:05.375 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "In Progress"

Note that I tryed KStars 3.6.5 earlier but could not get plate solve working, even with the simulators. I was able to get it working with 3.6.7 Beta using the simulators. See log below:

[2023-08-25T22:05:42.369 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "In Progress"
[2023-08-25T22:05:42.371 CDT INFO ][ org.kde.kstars.ekos.align] - "Capturing image..."
[2023-08-25T22:05:51.074 CDT INFO ][ org.kde.kstars.ekos.align] - "Image received."
[2023-08-25T22:05:51.082 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "In Progress"
[2023-08-25T22:06:56.733 CDT INFO ][ org.kde.kstars.ekos.align] - "Solver aborted after 65.65 seconds."
[2023-08-25T22:06:56.733 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "Aborted"
[2023-08-25T22:06:56.971 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "Failed"
[2023-08-25T22:07:03.157 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "In Progress"
[2023-08-25T22:07:03.159 CDT INFO ][ org.kde.kstars.ekos.align] - "Capturing image..."
[2023-08-25T22:07:11.890 CDT INFO ][ org.kde.kstars.ekos.align] - "Image received."
[2023-08-25T22:07:11.899 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "In Progress"
[2023-08-25T22:07:12.309 CDT INFO ][ org.kde.kstars.ekos.align] - "Solver completed after 0.41 seconds."
[2023-08-25T22:07:12.309 CDT INFO ][ org.kde.kstars.ekos.align] - "Solver RA (297.75701) DEC (8.86855) Orientation (89.97037) Pixel Scale (0.44570) Parity (neg)"
[2023-08-25T22:07:12.310 CDT INFO ][ org.kde.kstars.ekos.align] - "Effective telescope focal length is updated to 1,758.59 mm."
[2023-08-25T22:07:12.318 CDT INFO ][ org.kde.kstars.ekos.align] - "Solution coordinates: RA (19h 52m 11s) DEC ( 08° 55' 49\") Telescope Coordinates: RA (19h 52m 11s) DEC ( 08° 55' 53\") Target Coordinates: RA (19h 51m 57s) DEC ( 08° 55' 53\")"
[2023-08-25T22:07:12.319 CDT INFO ][ org.kde.kstars.ekos.align] - "Target is within 00° 03' 32\" degrees of solution coordinates."
[2023-08-25T22:07:12.319 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "Successful"
[2023-08-25T22:07:12.322 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "Syncing"
[2023-08-25T22:07:12.324 CDT INFO ][ org.kde.kstars.ekos.align] - "Syncing to RA (19h 52m 11s) DEC ( 08° 55' 49\")"
[2023-08-25T22:07:12.363 CDT INFO ][ org.kde.kstars.indi] - Telescope Simulator : "[INFO] Sync is successful. "
[2023-08-25T22:07:12.363 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "Slewing"
[2023-08-25T22:07:12.365 CDT INFO ][ org.kde.kstars.ekos.align] - Target coordinates updated to JNow RA: "19h 51m 57s" DE: " 08° 55' 53\""
[2023-08-25T22:07:12.366 CDT INFO ][ org.kde.kstars.ekos.align] - "Slewing to target coordinates: RA (19h 51m 57s) DEC ( 08° 55' 53\")."
[2023-08-25T22:07:12.449 CDT INFO ][ org.kde.kstars.indi] - Telescope Simulator : "[INFO] Slewing to RA: 19:51:57 - DEC: 8:55:53 "
[2023-08-25T22:07:12.583 CDT INFO ][ org.kde.kstars.indi] - Telescope Simulator : "[INFO] Telescope slew is complete. Tracking... "
[2023-08-25T22:07:12.583 CDT INFO ][ org.kde.kstars.ekos.align] - "Slew complete. Target accuracy is not met, running solver again..."
[2023-08-25T22:07:12.583 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "In Progress"
[2023-08-25T22:07:14.084 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "In Progress"
[2023-08-25T22:07:14.084 CDT INFO ][ org.kde.kstars.ekos.align] - "Capturing image..."
[2023-08-25T22:07:22.766 CDT INFO ][ org.kde.kstars.ekos.align] - "Image received."
[2023-08-25T22:07:22.773 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "In Progress"
[2023-08-25T22:07:23.172 CDT INFO ][ org.kde.kstars.ekos.align] - "Solver completed after 0.40 seconds."
[2023-08-25T22:07:23.173 CDT INFO ][ org.kde.kstars.ekos.align] - "Solver RA (297.69614) DEC (8.86864) Orientation (89.97452) Pixel Scale (0.44570) Parity (neg)"
[2023-08-25T22:07:23.177 CDT INFO ][ org.kde.kstars.ekos.align] - "Solution coordinates: RA (19h 51m 56s) DEC ( 08° 55' 49\") Telescope Coordinates: RA (19h 51m 56s) DEC ( 08° 55' 53\") Target Coordinates: RA (19h 51m 57s) DEC ( 08° 55' 53\")"
[2023-08-25T22:07:23.178 CDT INFO ][ org.kde.kstars.ekos.align] - "Target is within 00° 00' 08\" degrees of solution coordinates."
[2023-08-25T22:07:23.179 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "Successful"
[2023-08-25T22:07:23.181 CDT INFO ][ org.kde.kstars.ekos.align] - "Target is within acceptable range."
[2023-08-25T22:07:23.182 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "Complete"

I know that the collimation of my C11 SCT is pretty bad and need to be addressed. Could this cause the issues? Take a look at the attach align.jpeg file (fits file is too large .)

FWIW, I had no issue running a blind solve on your align.jpg image using 3.6.7beta.
Solver success in 3.4s: RA 297.61 DEC 7.69 Scale 1.36 Angle -93.50
So, though it would be nice to collimate your scope, I don't think that's your plate-solving issue.

Common advice is to uncheck "use position" and "use scale", not because because they are bad to use, but because often somehow there are bad values in there.
You might first try to add the right scale and position (see above) and keep them checked and see if it solves.
If that doesn't work, then uncheck them.

You (probably accidentally) included your home address as the last attachment. You probably want to delete that.

When showing what settings you're using, you should include the "Scale & Position" tab, and the "Align Options Profile" tab, and perhaps the main Align page.

If you do want to share a fts file, just upload it somewhere (e.g. dropbox or google drive) and share the link

Hy

I also have had significant plate solving issues. I have finally settled on using astap local solving.
My setup is a 100 mm f9 OTA. My camera is a Canon 1300D.
Observations I have made include:
1. It is dependent on the number of stars it identifies. The threshold seems to be in the hundred range.
2. In order to increase identified stars I have switched to bin 2x2 or even 3x3. It appears to be star shape dependent so I have also managed exposure time.
It still has periods where it does not solve. I have found it is dependent on the above.
It also leaves artifacts in the /tmp directory, it is necesary to flush those periodically.
I am still looking for the astap logs.

Hy,

1. How did you perform a blind solve in Kstars? Load and Slew with no action selected?
2. It's cloudy, so I'm testing with the simulator. It's simply not working and I can't determine what is it doing. Is there a debugger I can run?
3. Under the StellarSolver Options, what options should I be using?

Is there any documentation? The Kstars Guide is based on the much older astrometry.net bits, and I don't know what the acronyms mean (what is SEP and Sextractor?)

I'm puzzled and don't know what to do. Below are the verbose logs, but they really don't indicate what is going on:

[2023-08-26T21:33:02.899 CDT INFO ][ org.kde.kstars.indi] - Telescope Simulator : "[INFO] Mount is unparked. "
[2023-08-26T21:33:12.658 CDT INFO ][ org.kde.kstars.ekos.align] - Target coordinates updated to JNow RA: "00h 10m 27s" DE: " 59° 16' 43\""
[2023-08-26T21:33:12.691 CDT INFO ][ org.kde.kstars.indi] - Telescope Simulator : "[INFO] Slewing to RA: 0:10:27 - DEC: 59:16:43 "
[2023-08-26T21:33:12.834 CDT INFO ][ org.kde.kstars.ekos.guide] - "Mount is moving. Resetting calibration..."
[2023-08-26T21:33:12.834 CDT INFO ][ org.kde.kstars.ekos.guide] - "PHD2 Error: Equipment not connected."
[2023-08-26T21:33:12.834 CDT INFO ][ org.kde.kstars.ekos.guide] - "Calibration is cleared."
[2023-08-26T21:33:18.452 CDT INFO ][ org.kde.kstars.indi] - Telescope Simulator : "[INFO] Telescope slew is complete. Tracking... "
[2023-08-26T21:33:21.557 CDT DEBG ][ default] - QSGTextureAtlas: texture atlas allocation failed, code=500
[2023-08-26T21:33:46.096 CDT INFO ][ org.kde.kstars.ekos.align] - "Changing filter to Luminance..."
[2023-08-26T21:33:46.096 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "In Progress"
[2023-08-26T21:33:46.139 CDT INFO ][ org.kde.kstars.indi] - CCD Simulator : "[INFO] Setting current filter to slot 8 "
[2023-08-26T21:33:46.164 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "In Progress"
[2023-08-26T21:33:46.165 CDT INFO ][ org.kde.kstars.ekos.align] - "Capturing image..."
[2023-08-26T21:33:54.873 CDT INFO ][ org.kde.kstars.ekos.align] - "Image received."
[2023-08-26T21:33:54.964 CDT DEBG ][ org.kde.kstars.ekos.align] - Align state changed to "In Progress"

I find that if I don't stop the Capture and Slew, kstars eventually crashes.

Regards,

jmh

What I did was use my new image overlay feature
indilib.org/forum/general/13702-image-overlays.html
and use the jpeg you provided as an overlay.
I'm not saying that's the main way to debug plate solving.

Another way to do it, I suppose, is to use the load and slew functionality in align, and uncheck Use Position and Use Scale.

StellarSolver also has a StellarSolver_Tester program, but you may need to compile it to run it.

I'd recommend you post the screenshots I requested, and I can have a look.
Those are: scale and position tab in align options, align options profile tab in align options, main align page, and share a fits file stored on dropbox or google drive.

Hy

Forgot to answer your documentation questions.

There is a KStars Handbook, and many of the sections are up-to-date,
docs.kde.org/trunk5/en/kstars/kstars/kstars.pdf
but just checking now, it does look, like Align can use a refresh.
Still it would be worth reading.

Jasem does post a lot of videos on StellarSolver
www.youtube.com/channel/UC1x4aSvnUVtBNafANsD_Izg/videos
and they almost always apply equally to generic KStars/Ekos
but I don't see one on solving.

There are a lot of tooltips in the UI.

Here's a user-generated video on plate solving (sorry, haven't watched it, but have seen some of his other excellent videos)


Quick answers re SEP and SExtractor.
SEP is a professional astronomy library of star that implements SExtrator (probably star-extractor or source-extractor), which is, again, a professional astronomy library/program. If you are curious about it, you can find documentation here: astroa.physics.metu.edu.tr/MANUALS/sextr...source_extractor.pdf We use SEP for star extraction, as does StellarSolver. Many of the parameters you might enter to improve your star extraction and/or plate solving are SEP parameters. Plate solving works by first extracting star positions, and then finding areas in the sky where similar star patterns are found.

Hy


Happy to help answer questions on the forum.

Thanks for your quick response. I had just un-checked all the options in the Scale & Position tab, and plate solving now works fine, at least with the simulator. Tomorrow night should have less clouds so I'll test again with the real bits.

I was also looking at the Align Options Profiles Editor, and at the bottom where the Astrometry Parameters are listed, the Min Degree width and Search Radius look like they have values of zero. Is this correct? Not that is matters as it appears to be working. I've been away from this hobby just over a year, so apologies if I'm asking some daft questions.

Regards,

jmh

0 values there often mean "no constraint". Check the tool tips and that video.