Periodic Platesolving to combat dither drift

Sequence Generator Feature Requests
1

Hi Folks,

Firstly I want to say SG Pro was game changing for me, I honestly believe it has given me better value that any other piece of software or hardware I have bought. Sequence Recovery is simply a fantastic feature for me as I get clouds blowing past most nights.

Something I suffer from is that even medium drift will cause my image to drift over a few hours of imaging, this could be due to me having a smallish CCD sensor (Atik 460).

A feature that could mitigate this would be SG Pro periodically (say hourly) plate solving the latest sub exposure and if it the error is greater than a certain value it could correct or warn. I guess it comes down to:

  • Check-box to trigger Plate Solve every [x] mins, where x is user configurable.
  • Input field to allow user to define the number of pixel accuracy that is acceptable.
  • Option to either :
    • ‘Warn user of drift’ but continue imaging session.
    • SG Pro pause sequence and re-centre (or just trigger the sequence recovery dialogue).

I hope this is useful & thanks for providing such an amazing product.

Pete

2 Likes
2

Pete,

You may want to check out the Spiral Dither option in PHD2.

Description of the setting in the PHD Help:
https://openphdguiding.org/manual/?section=Advanced_settings.htm#Global_Tab

Details on how far dithering can be expected to wander with either dither mode:
https://groups.google.com/d/msg/open-phd-guiding/kDeNR8fRNs8/Cd7fH66aBQAJ

Andy

1 Like
3

As a work around, you could set up multiple targets for the each, with each one actually being the same target, and with centering on for each target. If you want to recenter hourly, set up each target to image for an hour. When it moves to the next target, it will recenter before imaging.

4

Thanks for the replies. I will swap over to square dither scale 1.0.

In the other link the chap suggests that 64 dithers is a lot of subs, for me it’s just 4hours of 3min luminance subs.