How satellite ‘megaconstellations’ will photobomb astronomy images

Re:How satellite ‘megaconstellations’ will photobomb astrono... by mdorazio on Thursday August 27, 2020 @11:00AM (#24294329)

I'm not sure you're thinking about it the right way. Or maybe I'm not. It seems you're assuming that every exposure you take will have a streak in the same spot from a satellite. It's more realistic that a large portion of exposures will have no streak at all, or that if you re-exposed a detector on the same piece of sky, any streak it would see the second time would be in a different place than the first. So if you expose twice and do some basic interpolation to remove the streaks, you would end up with an equivalent zero-satellite image from two exposures.

What am I missing?

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Re:How satellite ‘megaconstellations’ will photobomb astrono... by stripline on Thursday August 27, 2020 @02:31PM (#24296939)

The piece that people are missing is the concept of SNR, or signal-to-noise ratio. These streaks are noise, which raises your noise floor and thus raises your detection threshold. Think of the way your eyes adjust to bright light - you can no longer see dim things around it even if they aren't obscured.

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Re:How satellite ‘megaconstellations’ will photobomb astrono... by mdorazio on Thursday August 27, 2020 @04:25PM (#24298229)

Ok, I understand, thanks for clarifying. My next question would be how many exposures would you need in a real-world setting to mitigate the issue? Ex. what's the actual likelihood of a satellite crossing your target piece of sky during a randomly chosen exposure, and how long will it be in the exposure, messing with your SNR?

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