×

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

Bi-monthly release with minor bug fixes and improvements

Guiding csv file

  • Posts: 29
  • Thank you received: 5
Hi,

Does anyone have any ideas about what sort of information I could gleam from the .csv guide-log file saved using the KStars internal guider?

I can see the DEC and RA rms in the KStars guide-log in real time, but what else can i extract from the saved .csv file.
Using PhD2, there is a PHD2 log file viewer that allow you to see calibration data (stuff about orthogonality), and possible polar alignment error. I am trying to optimise my system to push towards 10minute subs.

My current setup is a follows using the Internal guider default settings and 2s exposures:
Mount:Celestron CGE
Primary Scope:ED120-ds-pro
Primary Camera: 450d
Guide Scope:WO 50mm/200mm Guidescope
Guide Camera:QHY5-L-ii-c.

5 minute subs are doddle but my 10 minute subs start to show drift.

Many thanks in advance,
Will.
Last edit: 5 years 9 months ago by Wilson Muchenje.
5 years 9 months ago #26669
Attachments:

Please Log in or Create an account to join the conversation.

Replied by Jasem Mutlaq on topic Guiding csv file

Robert is the man behind this feature, so I'll him tackle it, but I'd like to ask if you're using INDI Nightly or Stable PPA? Because we recently solved a guiding issue with Celestron (pulse guiding).
The following user(s) said Thank You: Wilson Muchenje
5 years 9 months ago #26676

Please Log in or Create an account to join the conversation.

  • Posts: 2876
  • Thank you received: 809

Replied by Rob Lancaster on topic Guiding csv file

So I added the ability to save the csv guide log so that you could save your guiding data so that you can come back to reference it later. Or maybe you might want to take the guiding data into a program like Excel to do some numerical analysis on it. Like for example, you might try to see if the guiding is better in certain areas of the sky, or perhaps it gets better at certain times. One thing you really might want to do is to analyze the data to see if there is a pattern to your guide error that relates to your worm gear cycle for your mount (there almost certainly is one). There might be other periodic errors as well. Basically I was thinking that we are recording all this great guiding data, why not make it available if somebody wants to save it or analyze it in another program. I was not thinking about one particular purpose at the time, just making it possible to easily save the data if somebody wanted to do something with it.
The following user(s) said Thank You: gehelem, Wilson Muchenje
5 years 9 months ago #26677

Please Log in or Create an account to join the conversation.

  • Posts: 29
  • Thank you received: 5

Replied by Wilson Muchenje on topic Guiding csv file

Thanks for the replies.
@Jasem, I am using the indi nightly. I've been following another topic on the Celestron mounts pulse guiding. I'm due some clear skies tomorrow for a test after updating kstars to the newest nightly.

I have used excel to plot to data. I can basically reproduce the guiding graph and the crosshair target showing deviations per guiding frame.
What sort of numerical analysis can I do to inspect for periodic error?
Another question is, does the internal guider perform any sort of periodic error compensation during the guiding process or is that something an external app like phd2 can do?

Best wishes,
Will.
Last edit: 5 years 9 months ago by Wilson Muchenje.
5 years 9 months ago #26697

Please Log in or Create an account to join the conversation.

  • Posts: 2876
  • Thank you received: 809

Replied by Rob Lancaster on topic Guiding csv file

I don't think either one can do that. What you want is actually a feature built into most mounts called Periodic Error Correction.

Offhand I do not know the algorithm for looking for periodic error in a program like excel, but I definitely remember some things I did back in college where we were looking for periodic trends in variable stars. I think it was called phase shifting. I would bet the same kind of algorithms can be used on these data as well. One thing you might want to do is to find out the period of the worm in your mount, then you could split the data up into segments corresponding to each cycle of your worm. You could then graph all of them on the same graph and see if you see the same bump in the guiding error on each cycle of the worm or something.

Thanks,

Rob
The following user(s) said Thank You: Wilson Muchenje
5 years 9 months ago #26699

Please Log in or Create an account to join the conversation.

  • Posts: 1029
  • Thank you received: 301

Replied by Eric on topic Re:Guiding csv file

As a side note, I watched this recent presentation from Dr Gaston Baudat on optimal guiding, and that might be of interest in your case:


-Eric
The following user(s) said Thank You: Wouter van Reeven
5 years 9 months ago #26901

Please Log in or Create an account to join the conversation.

Time to create page: 0.247 seconds