I was asleep and didn't witness it. That's a good thing, right? Nevertheless, it seems I lost the guide star, or at least guiding just stopped working. Ekos aborted guiding and restarted automatically. Guiding resumed and the next image began. Also a good thing. But, I found my subs on either side looked like this:
I'm posting this both in search of ideas (below) and in hopes that others might benefit from ideas around troubleshooting guiding.
Properly centered:
Uh, what? Calculating the center of the two shows they're 0.20 degrees off from each other. Wow.
Checking the logs, I see this event directly between these two subs:
[2018-02-21T03:44:07.330 MST DEBG ][ org.kde.kstars.ekos.guide] - Received guide frame.
[2018-02-21T03:44:07.330 MST DEBG ][ org.kde.kstars.ekos.guide] - Tracking Square QRect(22,4 32x32)
[2018-02-21T03:44:07.331 MST DEBG ][ org.kde.kstars.ekos.guide] - ################## BEGIN PROCESSING ##################
[2018-02-21T03:44:07.331 MST DEBG ][ org.kde.kstars.ekos.guide] - Star X : 37.1411 Y : 19.6493
[2018-02-21T03:44:07.331 MST DEBG ][ org.kde.kstars.ekos.guide] - Reticle X : 71.6676 Y : 66.8336
[2018-02-21T03:44:07.331 MST DEBG ][ org.kde.kstars.ekos.guide] - Star RA: 29.0457 DEC: 15.3665
[2018-02-21T03:44:07.331 MST DEBG ][ org.kde.kstars.ekos.guide] - Reticle RA: 56.0468 DEC: 52.2665
[b][2018-02-21T03:44:07.331 MST DEBG ][ org.kde.kstars.ekos.guide] - -------> BEFORE ROTATION Diff RA: -27.001 DEC: 36.9
[2018-02-21T03:44:07.331 MST DEBG ][ org.kde.kstars.ekos.guide] - -------> AFTER ROTATION Diff RA: 27.1894 DEC: -36.761[/b]
[2018-02-21T03:44:07.331 MST DEBG ][ org.kde.kstars.ekos.guide] - RA channel ticks: 22 DEC channel ticks: 22
[2018-02-21T03:44:07.331 MST DEBG ][ org.kde.kstars.ekos.guide] - Processing Axes
[2018-02-21T03:44:07.331 MST DEBG ][ org.kde.kstars.ekos.guide] - At # 22 drift[ 0 ][ 22 ] = 27.1894 , t_delta: 27.1894
[2018-02-21T03:44:07.331 MST DEBG ][ org.kde.kstars.ekos.guide] - delta [ 0 ]= 27.1894
[2018-02-21T03:44:07.331 MST DEBG ][ org.kde.kstars.ekos.guide] - drift_integral[ 0 ]= 9.75255
[2018-02-21T03:44:07.331 MST DEBG ][ org.kde.kstars.ekos.guide] - pulse_length [ 0 ]= 3624
[2018-02-21T03:44:07.331 MST DEBG ][ org.kde.kstars.ekos.guide] - Direction : Decrease RA
[2018-02-21T03:44:07.331 MST DEBG ][ org.kde.kstars.ekos.guide] - At # 22 drift[ 1 ][ 22 ] = -36.7613 , t_delta: -36.7613
[2018-02-21T03:44:07.331 MST DEBG ][ org.kde.kstars.ekos.guide] - delta [ 1 ]= -36.7613
[2018-02-21T03:44:07.331 MST DEBG ][ org.kde.kstars.ekos.guide] - drift_integral[ 1 ]= -12.5693
[2018-02-21T03:44:07.331 MST DEBG ][ org.kde.kstars.ekos.guide] - pulse_length [ 1 ]= 4900
[2018-02-21T03:44:07.331 MST DEBG ][ org.kde.kstars.ekos.guide] - Direction : Decrease DEC
[2018-02-21T03:44:07.331 MST DEBG ][ org.kde.kstars.ekos.guide] - ################## FINISH PROCESSING ##################
[b][2018-02-21T03:44:07.332 MST DEBG ][ org.kde.kstars.ekos.guide] - Aborting "Guiding"[/b]
Guiding aborted, presumably because the guide star moved outside of the box (64x64). I'll be testing guiding without a box the next good night of weather. Regardless, I like to know how and why a system does the things that it does.
I happen to log RA/Dec to a different system every 10 seconds and noticed that both diverged in a very short time frame in between the two subs above. No slew commands were captured, so the input must have been from the guiding system in Ekos:
And here is the result of the diffs in the Ekos log file during the event:
And for reference, what it looked like in a normal state (RA & Dec swapped here? This is from the logs. Hmm):
So, in spite of all of this data I can still only guess:
- Maybe clouds came through? Some of the subs suggest it as a possibility but I'm not sure of it.
- Did the quality of the guide star change somehow?
- Did the guide star really move? Not sure - sometimes I find it guiding or focusing on nothing.
- Did the mount slew or otherwise get moved? External logs show the mount did not slew, but RA and Dec did adjust by way of guiding.
Is there any other data point I'm missing? If not, it might be good to have two things for the wish list:
- A way to log the quality of the guide star. Perhaps ADU count of the guide star from guide frame to guide frame would be good?
- Also nice - the RA & Dec of the guide star used!
- Greg