How satellite ‘megaconstellations’ will photobomb astronomy images • Hacker News Board

Re: How satellite ‘megaconstellations’ will photobomb astronomy images

#301

Post by mdorazio » Thu, Aug 27, 2020, 8:25 PM UTC

stripline wrote: post #264

mdorazio wrote: post #218

Earlier quoted context omitted.

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…

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.

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?

Re: How satellite ‘megaconstellations’ will photobomb astronomy images

#302

Post by elsonrodriguez » Thu, Aug 27, 2020, 8:33 PM UTC

verytrivial wrote: post #15

The article covers the mitigations already in place and how they only partially resolve the issue. These satellites are low, bright (at dawn/dusk) and very soon to be incredibly numerous. Yes, it is possible for data workflows to post-process these streaks away, but not all configurations allow this, and whereas previous intrusions were somewhat rare and could be ignored that simply won't be the case due to three com…

The future of the night sky was always one filled with satellites and space ships and drive plumes.

It's silly to die on a hill that's inevitable, it's much wiser to stand on the hill and reach higher. The future of space exploration is in space, not on the ground, and the proliferation of these satellites is a sign that space exploration is getting cheaper.

Just like people were shocked that there was only one or two computers in the world at one point, they will be shocked that we only had Hubble for so long.

Re: How satellite ‘megaconstellations’ will photobomb astronomy images

#303

Post by arthropodSeven » Thu, Aug 27, 2020, 8:36 PM UTC

it's hard to make the claim that the private development of space doesn't inspire people in the same way as the old national projects did. my heart swells watching a livestream of a satellite being delivered into orbit. but "memelord space magnate delivers global internet access" doesn't give the endeavor the gravity it deserves.

space is the last realm of mystery. to me, a glance toward the sky and the stars has always been the fastest way to feel the presence of God. it won't lose that for me, even if the daytime sky fills up with blinkenlights. but it might not provide that for anyone else, anymore, if it stays—forgive me—on this trajectory.

> The planets are all long gone. The inkblot finally closes overhead and the last star winks out. The gibbous Moon remains shining balefully down on the world for a tense and hopeful minute, but then, in an eyeblink, is swallowed up by one final event horizon, and spirited away.

> Left in utter darkness, the former astronomer tries and fails to deal rationally with his loss, and his isolation from the human race who, as the voice rightly tried to tell him, has really lost nothing.

https://qntm.org/astronomer

Re: How satellite ‘megaconstellations’ will photobomb astronomy images

#304

Post by beambot » Thu, Aug 27, 2020, 8:41 PM UTC

elsonrodriguez wrote: post #302

verytrivial wrote: post #15

The article covers the mitigations already in place and how they only partially resolve the issue. These satellites are low, bright (at dawn/dusk) and very soon to be incredibly numerous. Yes, it is possible for data workflows to post-process these streaks away, but not all configurations allow this, and whereas previous intrusions were somewhat rare and could be ignored that simply won't be the case due to three com…

The future of the night sky was always one filled with satellites and space ships and drive plumes. It's silly to die on a hill that's inevitable, it's much wiser to stand on the hill and reach higher. The future of space exploration is in space, not on the ground, and the proliferation of these satellites is a sign that space exploration is getting cheaper. Just like people were shocked that there was only one or tw…

Indeed! We're within reach of telescopes on the backside of the moon, or ultra-long baseline radio telescopes in high Earth Orbit. This is the dawn of a new era of space research. The transition may be unpleasant, but the future is exciting!

Re: How satellite ‘megaconstellations’ will photobomb astronomy images

#305

Post by batt4good » Thu, Aug 27, 2020, 8:58 PM UTC

I'm pretty pissed billionaires and their stupid toy internet projects have ruined my chances of taking a clear picture of the asteroid in my name (won at an Intel ISEF science & engineering olympiad in high school) for the foreseeable future :( .

It only transits the earth into a position where the sun lights it up every three years - I'm still working on finding a university to aim a spectrometer / laser at it so I can identify it's mineral composition and decide how much to charge asteroid miners for it ;)

Re: How satellite ‘megaconstellations’ will photobomb astronomy images

#306

Post by 0-_-0 » Thu, Aug 27, 2020, 9:04 PM UTC

klyrs wrote: post #221

0-_-0 wrote: post #163

Earlier quoted context omitted.

(can't reply below) If you had a localised shutter covering pattern X for 6 seconds, could you compensate for that by covering the inverse pattern of X for 6 seconds to get the same exposure for all pixels? So if you covered 3 satellite streaks of 6 seconds each using non-verlapping patterns (A,B,C) you could compensate for that by ending your exposure with covering the inverse of A+B+C for 6 seconds, adding only 6 s…

Herein lies the problem. Your proposed solutions are ever more complicated as you begin to grasp the magnitude of the issue. Implementing this idea, and I'm not saying that it's good enough, would require modifications to pretty much every major telescope in the world. And there's no economy of scale because most of them are custom builds. Who's gonna pay for that?

That is only necessary in a small fraction of cases. You can just ignore the part with the streak or lower the shutter when you're using existing equipment.

Re: How satellite ‘megaconstellations’ will photobomb astronomy images

#307

Post by ballooney » Thu, Aug 27, 2020, 9:19 PM UTC

gorgoiler wrote: post #300

mmaunder wrote: post #284

Earlier quoted context omitted.

I’m afraid you will die on that hill and be replaced by a happy rural resident who was being abused by a local telco monopoly, but is now using competitively priced, fast, low latency satellite internet. Using keps and scrubbing exposures in post is something we could already do decades ago. It’ll just be a new part of the workflow and eventually the space NIMBYs will quiet down.

Spaceships and radio waves are cool and provide a unique solution. Let’s not pretend this was the one true way to get around Comcast et al’s stranglehold though. That problem could have been solved politically with regulation plus (in the countryside) ground based radio, or (in cities) with regulation of cable infrastructure such that it was separated from packet-routing and customer-service. If satellite ISPs genuin…

This should be the top comment. It’s an especially prevalent view in the USA that bad politics is a law of physics and the only solutions are madly technological. It’s not true as many other parts of the world prove. You can just have a not-insane ISP/telco regulatory system if you so choose. (see also healthcare, food/agricultural standards, water quality, online privacy... all choices).

Re: How satellite ‘megaconstellations’ will photobomb astronomy images

#308

Post by ImaCake » Thu, Aug 27, 2020, 9:22 PM UTC

Balgair wrote: post #175

ImaCake wrote: post #116

Earlier quoted context omitted.

I guess you could statistically impute that data. But it is the long tail of unlikely readings which are generally interesting, and imputation will not find those.

Unfortunately, the 'glow' is from the optics, not the CCD (you'd see streaks or 'boxing' that way). You can't statistically impute the optics, as these issues are based on physics. A good starter article here; http://spiff.rit.edu/classes/phys312/workshops/w10c/telescop...

Thanks, that was a fun read. I think I have a better grasp of why you can't impute this now.

Re: How satellite ‘megaconstellations’ will photobomb astronomy images

#309

Post by jessaustin » Thu, Aug 27, 2020, 9:26 PM UTC

stickfigure wrote: post #296

mmaunder wrote: post #284

Earlier quoted context omitted.

I’m afraid you will die on that hill and be replaced by a happy rural resident who was being abused by a local telco monopoly, but is now using competitively priced, fast, low latency satellite internet. Using keps and scrubbing exposures in post is something we could already do decades ago. It’ll just be a new part of the workflow and eventually the space NIMBYs will quiet down.

We have pitchforks and know how to use them. -- Rural Resident

That's not the extent of our arsenal.

Re: How satellite ‘megaconstellations’ will photobomb astronomy images

#310

Post by jessaustin » Thu, Aug 27, 2020, 9:30 PM UTC

NationalPark wrote: post #180

reitzensteinm wrote: post #142

Earlier quoted context omitted.

This isn't about being able to afford infrastructure. It's about population density in rural areas. North America and Australia (where I'm from) have the exact same issue. No country is going to spend a million bucks to lay fiber to ten person towns in the middle of nowhere.

The U.S. actually does do this! The FCC alone spends more than $2bn annually subsidizing telecom infrastructure in rural areas. There are a number of other similar programs, and Ajit Pai (current FCC chairman) recently proposed another $20bn of spending on subsidies for rural internet connections: https://www.fcc.gov/document/fcc-proposes-204-billion-rural-...

If Ajit actually cared he'd unlicense more spectrum. Paying the Daughters Bell our own tax money to encourage them to further victimize us is fascist.