Satellite Streaks in long exposures

[chemistorge]

Hi,

 

While taking my first go at part of the veil nebula, I noticed that I was throwing out 10 % + subs to satellite streaks. (106x 120s).

 

What is other people’s experience of streaks? Is it getting worse?

Edited August 18, 2021 by chemistorge

[Seelive]

I always a use kappa-sigma stacking method so I don't waste any subs with satellite or aircraft trails.

[chemistorge]

Ah, does that get rid of them?

[Seelive]

23 minutes ago, chemistorge said:

Ah, does that get rid of them?

Yes, you need at least a dozen or more lights for it to work its magic but if you stack sufficient lights they totally dissappear. I live underneath the flight path to an airport so planes are also a problem for me (and they are much brighter than satelites, but still are removed)

[nephilim]

If your guiding then I recommend dithering, not only will it get rid of plane/ satellite trails but it'll also remove hot pixels (I may be wrong but there looks like a fair few in your image) and can help decrease the amount of fixed pattern noise but mainly in DSLR's. 

Have a look at the YouTube clip in this link  https://astrobackyard.com/dithering-astrophotography/

[chemistorge]

@Seelive Thank you for that, I am using DSS and do use kappa-sigma, I didn't realise it got rid  of them.

 

@nephilim I didn't guide because I get good tracking with 120 sec subs. I use around 40 darks and 40 flats, but I forgot to turn on manual dithering in Ekos, it causes issues if you try and guide with manual dithering set, so I turn it off (and forget to turn back on when not guiding). I do need more practise at processing. Only just got all my equipment working well together (ASI294mc, Astroberry (kstars/ekos), SW130p (modded with dual crayford electronic forcuser) and SW eq5 (AstroEQ mod).  

[Chefgage]

2 hours ago, nephilim said:

If your guiding then I recommend dithering, not only will it get rid of plane/ satellite trails but it'll also remove hot pixels (I may be wrong but there looks like a fair few in your image) and can help decrease the amount of fixed pattern noise but mainly in DSLR's. 

Have a look at the YouTube clip in this link  https://astrobackyard.com/dithering-astrophotography/

Dithering will not get rid of satellite/plane trails though. The dithering is done between each image so the satellite/plane trail will still be there. Stacking software such as DSS can effectively remove them though using the kappa sigma stacking lime has been mentioned above.

[nephilim]

44 minutes ago, Chefgage said:

Dithering will not get rid of satellite/plane trails though. The dithering is done between each image so the satellite/plane trail will still be there. Stacking software such as DSS can effectively remove them though using the kappa sigma stacking lime has been mentioned above.

@Chefgage I didnt realise that I'd just seen it written here & AstroBackyard tends to be pretty reliable?? Copied from the Website.... Dithering improves the signal-to-noise ratio (SNR) and can remove artifacts like hot pixels and satellite trails. Images shot with a regular DSLR camera can benefit from dithering, by helping to decrease the amount of fixed pattern noise.  
 

Edited August 18, 2021 by nephilim

[nephilim]

1 minute ago, nephilim said:

@Chefgage I didnt realise that I'd just seen it written here & AstroBackyard tends to be pretty reliable?? Copied from the Website.... Dithering improves the signal-to-noise ratio (SNR) and can remove artifacts like hot pixels and satellite trails. Images shot with a regular DSLR camera can benefit from dithering, by helping to decrease the amount of fixed pattern noise.  
 

@Chefgage Although what your saying about it been done between imaging actually makes sense that it wouldnt remove them.

[Chefgage]

1 hour ago, nephilim said:

@Chefgage Although what your saying about it been done between imaging actually makes sense that it wouldnt remove them

I have found that yes, dithering helps reduce noise when using a dslr but certainly not removing trails from satellites and planes  (not sure why it is mentioned in that quote). I can only guessthat by having less noise the stacking software has an easier time removing the trails. Although i never delete any image with trails and dss removes them wether i dithered or not.