Author Topic: Help with rejection during stacking  (Read 2218 times)

Offline joelshort

  • PixInsight Addict
  • ***
  • Posts: 260
    • Buckeyestargazer.net
Help with rejection during stacking
« on: 2017 February 20 06:04:49 »
I've run into a stacking problem that I have not seen before.  I am stacking 18 images that were dithered, using either Linear Fit Clipping or Windsorized Sigma Clipping. 

Apparently there is a common satellite path in the area I was imaging.  The problem is that almost all of the subs contain satellite trails in the same general location in the images, and they are quite faint.  No matter what settings I use for rejection I cannot eliminate the satellite trails completely because they are just a little bit brighter than the background.  Actually, the trails are largely eliminated in the dark background areas but where the trails go through the nebula I can't get rid of them. 

Any advice?  Thanks in advance.
Joel Short
www.buckeyestargazer.net
CFF135 f6.7, SV80ST, G3-16200M, QHY163M, QHY183M

Offline pfile

  • PTeam Member
  • PixInsight Jedi Grand Master
  • ********
  • Posts: 4729
Re: Help with rejection during stacking
« Reply #1 on: 2017 February 20 09:22:12 »
i think there is a thread here somewhere where RickS suggested using pixelmath to "zap" the trails with a white line in each sub, thus making them easier to reject.

rob

Offline joelshort

  • PixInsight Addict
  • ***
  • Posts: 260
    • Buckeyestargazer.net
Re: Help with rejection during stacking
« Reply #2 on: 2017 February 20 09:29:58 »
Thanks pfile.  I believe this is the correct thread:  http://pixinsight.com/forum/index.php?topic=9917.msg62886#msg62886
Joel Short
www.buckeyestargazer.net
CFF135 f6.7, SV80ST, G3-16200M, QHY163M, QHY183M

Offline oldwexi

  • PixInsight Guru
  • ****
  • Posts: 627
    • Astronomy Pages G.W.
Re: Help with rejection during stacking
« Reply #3 on: 2017 February 20 09:34:52 »
max($T,1-d2seg(427,350,154,297))
creates a 1 pixel wide line from xy 427,350 to xy 154,297

max($T,4-d2seg(427,350,154,297))
creates a 4 pixel wide line from xy 427,350 to xy 154,297

etc..

into the actual image

Gerald