Calibration Setting...
 
Share:
Notifications
Clear all

15th Feb 2024: Astro Pixel Processor 2.0.0-beta29 released - macOS native File Chooser, macOS CMD-Q fixed, read-only Fits on network fixed and other bug fixes

7th December 2023:  added payment option Alipay to purchase Astro Pixel Processor from China, Hong Kong, Macau, Taiwan, Korea, Japan and other countries where Alipay is used.

 

Calibration Settings for Plane/Satellite Trails?

12 Posts
6 Users
0 Likes
4,387 Views
(@whixson)
Black Hole
Joined: 6 years ago
Posts: 164
Topic starter  

What and where are the settings appropriate for dealing with airplane and satellite trails? Normally I have over 20 lights and darks. 

Wayne


   
ReplyQuote
(@schurig)
Neutron Star
Joined: 7 years ago
Posts: 71
 

Hello Wayne,

The good news is: airplane and satellite trails won't apprear on darks 🙂

And for the lights go like this: When using the outlier rejection filter (in combination with "average" when having approx. at least 20 frames), I always use the default, which is kappa 3 and iterations 1. I ALWAYS check the "create outlier rejection map" to see what pixels were rejected. If the final stack image still contains trails I increase the level of outlier rejection, either increasing iterations or lowering kappa to 2.5. But, I also review all singe frames before stacking and manually delete bad ones, e.g. when there is a heavy trail right through the object.

Kind regards, Stephan


   
ReplyQuote
(@jtrezzo)
Main Sequence Star
Joined: 6 years ago
Posts: 16
 

I am having trouble with this as well. The geosynchronous satellites in Orion, since they are are on EVERY frame and right in the same location, they are not getting rejected. So far I have tried increasing iterations to 2 and lowering kappa to 2.5, but they are still showing up in the integration. 

What is the most aggressive I can get with these settings before damaging the rest of the image? I am using LN MAD winsor clipping, average integration, weights by quality, and have about 350 frames.

This post was modified 5 years ago 2 times by jtrezzo

   
ReplyQuote
(@schurig)
Neutron Star
Joined: 7 years ago
Posts: 71
 

How do they appear in the image? As as a spot? If they are in every frame at the same position you cannot use outlier rejection. You can use photoshop to erase them.

stephan

 


   
ReplyQuote
(@jtrezzo)
Main Sequence Star
Joined: 6 years ago
Posts: 16
 

They are streaks across the top. See the heavily stretched image here. This was just the first 2.5 hours of data. They aren't the same in every frame by any means but they go right across the same general area and I'm guessing overlap in several frames. 

received 778913689120502

   
ReplyQuote
(@schurig)
Neutron Star
Joined: 7 years ago
Posts: 71
 

That's difficult. Try outlier rejection with different parameters (start with kappa 2,5 and decrease, increase iterations). But I think the trails cannot be eliminated completely when you describe them such present in every frame...


   
ReplyQuote
(@vincent-mod)
Universe Admin
Joined: 7 years ago
Posts: 5707
 

Yes that region of space is probably the worst concerning satellite trails. Most seem to be rejected I think, looking at the final stretch, but it might require some extra post-processing to get it completely gone, likely in another program. More aggressive dithering might help (I always do that especially on this region) as well as more aggressive rejection. If it hurts some details, but does remove the trails then that's the trade-off you will have to make given the data. If the date is dithered very well it might already improve.


   
ReplyQuote
(@jtrezzo)
Main Sequence Star
Joined: 6 years ago
Posts: 16
 

Here is the final image. I took more frames (over 300 total) and got up to 6.5 hours and I did dither fairly aggressively every 5 frames. If you look really hard you can see a faint trail where the satellite path was worst, but it is significantly less prominent than the image posted above. So it seems just having more images helped here, as I did not change the settings for rejection.

 

8dIMcpJGl4OV 1824x0 wmhqkGbg

   
ReplyQuote
(@vincent-mod)
Universe Admin
Joined: 7 years ago
Posts: 5707
 

Yes more images will give you more variation which is then averaged out better. I actually dither every frame for this object (set on High with Sequence Generator Pro), it really helped also with less images.

Very nice image btw, love the brown.


   
ReplyQuote
(@carsan)
Main Sequence Star
Joined: 2 years ago
Posts: 24
 

Can you tell me the settings to leave satellites in the integrated image? I want to show an image with lots all the satellites in it. (BTW the satellites have been removed very well from all but one of my images.) Thanks.

This post was modified 1 year ago by Carol Santulis

   
ReplyQuote
(@wvreeven)
Quasar
Joined: 6 years ago
Posts: 2133

   
ReplyQuote
(@carsan)
Main Sequence Star
Joined: 2 years ago
Posts: 24
 

@wvreeven Thanks Wouter!


   
ReplyQuote
Share: