×

INDI Library v1.9.8 Released (29 Sep 2022)

Bi-monthly INDI Library released with new drivers and bug fixes.

How does PEC/PPEC & GPG work to help RA guiding

  • Posts: 915
  • Thank you received: 429
If you go to the GPG Options page (described above) and enter the mount period in "Major Period", and click apply, then KStars should remember it.
If "Estimate Period" is not checked, then the period should not be updated by GPG.
As I said, either look up the period if it's on the PHD2 Wiki page above, or keep a good estimate from a successful KStars GPG session that lasted
a long time, e.g. over an hour since the last slew or other GPG reset.

AP1100 & Orion Atlas Pro, WO/ZS105 w/Moonlight V2 focus, GSO RC10 w/RSF focus
ZWO ASI1600, Astronomik Filters, ST80, QHY 5L-IIm.
KStars/Ekos/Indi on NUC10 & RPi4 w/SSD -- Ubuntu
Projects: Greedy Scheduler, Terrain, Polar Align, Analyze, Linear Focuser, SEP MultiStar & GPG Guide, FITS autostretch.
1 year 10 months ago #66305
Attachments:

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

  • Posts: 10
  • Thank you received: 2
I have a question about the GPG period in seconds. I noticed that it must be an integer. If the period of my mount is 239.5 seconds, then after an hour (15 periods of 240 seconds) it will be 15*0.5=7.5 seconds off a multiple of 240. Does that mean that my GPG will then be out of sync by 7.5 seconds if I enter 240 as the period, and don't click the "estimate period" checkbox (as recommended)? If it does, can the integer period be changed to a floating-point number?
3 months 1 week ago #85520

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

  • Posts: 915
  • Thank you received: 429
Henk,

The period was changed to a float input, I believe in 3.5.8
invent.kde.org/education/kstars/-/merge_requests/542

Hy
AP1100 & Orion Atlas Pro, WO/ZS105 w/Moonlight V2 focus, GSO RC10 w/RSF focus
ZWO ASI1600, Astronomik Filters, ST80, QHY 5L-IIm.
KStars/Ekos/Indi on NUC10 & RPi4 w/SSD -- Ubuntu
Projects: Greedy Scheduler, Terrain, Polar Align, Analyze, Linear Focuser, SEP MultiStar & GPG Guide, FITS autostretch.
The following user(s) said Thank You: Henk Aling
3 months 1 week ago #85522

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

  • Posts: 10
  • Thank you received: 2
One last question: How is a linear trend accounted for? IMHO it should be considered separately as there will always be some trend due to polar misalignment, atmospheric refraction, clutch slippage, etcetera. A trend is a non-periodic signal so when not properly accounted for, it may to additional errors rather than reduced errors.
3 months 4 days ago #85688

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

  • Posts: 915
  • Thank you received: 429
Henk,

Check out Klenske's thesis here:
www.research-collection.ethz.ch/bitstrea...quence=2&isAllowed=y

In particular, look at chapter 6, "Software Implementation: PHD2 Guiding". We use the same GPG source library that PHD2 does, which was written by Klenske et al.
invent.kde.org/education/kstars/-/tree/m..._IS_gaussian_process

In particular, he does mention how there's both periodic error correction as well as correction for drifts built into GPG. Also, of course, there is standard control built in to the guider to account for other types of "random error".

Hy
AP1100 & Orion Atlas Pro, WO/ZS105 w/Moonlight V2 focus, GSO RC10 w/RSF focus
ZWO ASI1600, Astronomik Filters, ST80, QHY 5L-IIm.
KStars/Ekos/Indi on NUC10 & RPi4 w/SSD -- Ubuntu
Projects: Greedy Scheduler, Terrain, Polar Align, Analyze, Linear Focuser, SEP MultiStar & GPG Guide, FITS autostretch.
3 months 3 days ago #85707

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

Time to create page: 0.693 seconds