Hello,

So last night I left the rig on an imaging run (Leo Triplet) that was meant to finish at around 0120 w a job (m81) scheduled to start from 0130.  I thought that the Leo run may not finish all its images (time added for dithering & settling etc), and was curious to see what would happen.

Looked this morning, and happily the scheduler took priority at 0130, the Leo run was terminated and the mount slewed and aligned successfully on M81.

But then the guiding seems to have been the problem - it couldn't calibrate.  But it was a clear night (the plateseolving & alignment worked so it can't be have been clouds at that time, and it was guiding fine for the Leo run).

Slightly disappointing b/c it was 4 hrs of missed moonless skies.  Hey ho, M81 will still be there in the future, but it would be good to understand how/why this happened b/c if Scheduler is going to be unreliable I am going to have to change my imaging sequencing.

Log file here: www.dropbox.com/s/20ydmtxbytvtpr2/log_20-37-09.txt?dl=0

Guidelog file here: www.dropbox.com/s/cs0gjg36k2syh03/guide_...06T20-45-50.txt?dl=0

Thank you!

I looked through your log and wanted to mention a few things:

1) Calibration started at 1:33:29 and failed at 1:40:35

2) Looking at the log for the star detection output during that time you can see that it starts out OK, but has trouble finding stars before it fails:[2022-02-07T01:33:32.328 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 10 stars, 0.09s"
[2022-02-07T01:33:55.935 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 33 stars, 0.08s"
[2022-02-07T01:34:19.577 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 40 stars, 0.09s"
[2022-02-07T01:34:43.188 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 40 stars, 0.09s"
[2022-02-07T01:35:06.990 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 35 stars, 0.10s"
[2022-02-07T01:35:30.698 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 27 stars, 0.07s"
[2022-02-07T01:35:54.327 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 34 stars, 0.08s"
[2022-02-07T01:36:17.907 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 32 stars, 0.08s"
[2022-02-07T01:36:41.554 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 28 stars, 0.07s"
[2022-02-07T01:37:01.113 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 17 stars, 0.04s"
[2022-02-07T01:37:01.179 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 17 stars, 0.05s"
[2022-02-07T01:37:24.851 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 20 stars, 0.05s"
[2022-02-07T01:37:48.447 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 9 stars, 0.04s"
[2022-02-07T01:38:12.172 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 23 stars, 0.09s"
[2022-02-07T01:38:36.088 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 3 stars, 0.03s"
[2022-02-07T01:38:36.120 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 1 stars, 0.03s"
[2022-02-07T01:38:59.951 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 12 stars, 0.06s"
[2022-02-07T01:39:23.896 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 3 stars, 0.05s"
[2022-02-07T01:39:23.954 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 1 stars, 0.05s"
[2022-02-07T01:39:47.779 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 1 stars, 0.03s"
[2022-02-07T01:39:47.802 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 1 stars, 0.02s"
[2022-02-07T01:40:11.968 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 5 stars, 0.05s"
[2022-02-07T01:40:12.016 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 1 stars, 0.04s"
[2022-02-07T01:40:35.856 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Multistar: findTopStars returning: 1 stars, 0.03s"

So, I wonder if a cloud did pass by around 1:40am that wasn't there at 1:37am (or some other optical issue like perhaps shooting through a tree, etc).

3) Of course, it would be nice if Ekos recovered on its own after that--and, e.g. retried a few minutes later.
It does seem to retry, but fails to restart because of a scheduler configuration: See below:

Guiding fails and restars:

[2022-02-07T01:44:20.660 GMT INFO ][ org.kde.kstars.ekos.scheduler] - "Job 'M 81' is guiding, guiding procedure will be restarted in 20 seconds."

but then fails again

[2022-02-07T01:45:22.100 GMT DEBG ][     org.kde.kstars.ekos.guide] - Multistar: findTopStars 10
[2022-02-07T01:45:22.123 GMT DEBG ][     org.kde.kstars.ekos.guide] - "Select      #   x      y      flux    HFR  SNR   score"
[2022-02-07T01:45:22.123 GMT DEBG ][     org.kde.kstars.ekos.guide] - No suitable star detected.
[2022-02-07T01:45:22.124 GMT INFO ][     org.kde.kstars.ekos.guide] - "Failed to select an auto star."
[2022-02-07T01:45:22.211 GMT DEBG ][   org.kde.kstars.ekos.capture] - Guiding state changed from "Selecting star" to "Calibration error"

The scheduler then aborts the job, and I believe would try and restart it, but unfortunately the job had a "fixed start time" and the scheduler wasn't smart enough to ignore that.

[2022-02-07T01:45:22.360 GMT INFO ][ org.kde.kstars.ekos.scheduler] - "Job 'M 81' is stopping guiding..."
[2022-02-07T01:45:22.361 GMT INFO ][ org.kde.kstars.ekos.scheduler] - "Job 'M 81' is aborted."
[2022-02-07T01:45:43.125 GMT INFO ][ org.kde.kstars.ekos.scheduler] - "Only aborted jobs left in the scheduler queue, rescheduling those."
[2022-02-07T01:45:43.187 GMT INFO ][ org.kde.kstars.ekos.scheduler] - Option to sort jobs based on priority and altitude is true
[2022-02-07T01:45:43.298 GMT INFO ][ org.kde.kstars.ekos.scheduler] - "Warning: job 'M 81' has fixed startup time 07/02 01:30 set in the past, marking invalid."
[2022-02-07T01:45:22.218 GMT INFO ][ org.kde.kstars.ekos.scheduler] - "Warning: job 'M 81' calibration failed."I'd recommend constraining the scheduler without the fixed startup time.

4) This probably wouldn't have made a difference, but you don't need to recalibrate every time you slew. What I do is calibrate once near the meridian and equator, and reuse that as follows

 

Note that "reset guide calibration after each mount slew" is unchecked, and "store and reuse calibration when possible" is checked.
However, you have to know whether or not to check or uncheck "Reverse DEC on ..." which is a mount-specific setting.
You can find that out experimentally. Calibrate on one side of the merfian, then go over to the other side and try guiding for a minute. 
Guiding will be terrible in DEC if you have the setting wrong. It will be pushing in the wrong direction and should quickly move far from the target.

Thanks Hy, that's v helpful. I'll try that on the reverse DEC setting out of curiosity (I don't think I need to b/c when I've played w that in the past - out of sheer ignorance! - it's not been good; my mount is an HEQ5Pro).

Yes, I did look at the log the next day & wish it had kept trying (I'm still puzzled about what could have happened - the main scope with narrow FOV found & aligned fine, so I'd have thought that the guide scope with a much larger FOV would be less susceptible to a freak cloud since it would need to be a much bigger cloud which would also interfere with the primary scope; M81 was pretty much near the zenith at that time, so no way any trees or roof lines could have been a factor. A mystery).

On the keeping-trying aspect side of Scheduler, I didn't realise that was a one-time rule that it only tries at that time. The reason I set a time was b/c I was in the middle of an imaging run which was centred on empty space to get a particular framing. And so I just thought I'd set a time to switch to M81, b/c I couldn't figure out how to se the earlier target as a Scheduler run (the Scheduler seems to require a specified target, vs the ability to either put in specific co-ordinates, or put a load-and-solve file as the target - unless I'm missing something. If Scheduler could be set up to not need a named target that would be great b/c then I could do these all as Scheduler runs and w the Terrain tool also up & running, hopefully it would figure out by itself when to switch targets)?

Anyway, thanks for the pointers on the guide calibration - much appreciated.

@VIN
Centre your framed target -right click > centre and track- in kstars' and in the scheduler tab, hit the little '+' symbol as indicated to enter the coordinates of your centred target. Call it anything.
That's it.
HTH
 
 

Doh, I'm clearly an idiot, thanks @Alacant! I'd noticed that and hovered over the icon and where it says "Centre Sky Map Centre" just thought that was something else. This is v handy, thank you!

Can that be done for the Align function too? (I've noticed that if I load-and-slew to a particular FITS file location, and then meridian flip happens, the Align module seems to get lost about where it's meant to be looking for?).