Calibration Settings for Plane/Satellite Trails?  

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(@whixson)
Red Giant Customer
Joined: 3 months  ago
Posts: 61
November 25, 2018 19:59  

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

Wayne


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(@schurig)
Red Giant Customer
Joined: 1 year  ago
Posts: 62
November 28, 2018 13:30  

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


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(@jtrezzo)
Brown Dwarf Customer
Joined: 11 months  ago
Posts: 9
December 6, 2018 17:38  

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 6 days  ago 2 times by jtrezzo

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(@schurig)
Red Giant Customer
Joined: 1 year  ago
Posts: 62
December 6, 2018 17:59  

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

 


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(@jtrezzo)
Brown Dwarf Customer
Joined: 11 months  ago
Posts: 9
December 6, 2018 21:11  

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


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(@schurig)
Red Giant Customer
Joined: 1 year  ago
Posts: 62
December 7, 2018 09:02  

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...


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