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Ask HN: Which is the most powerful satellite camera directed towards earth?

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Re: Ask HN: Which is the most powerful satellite camera directed towards earth?

#41

Post by planteen »

hyperbovine wrote: post #29
KiwiCoder wrote: post #2

I expect drones are now more relevant than satellites for localised imaging. For example http://www.cropcopter.co/uav-imagery-vs-satellite/

Yes. There was a piece on 60 Minutes a few years back where they had a big (~20 ft. wingspan maybe), loud drone circling overhead a few thousand feet up. It was inaudible and invisible. What's the point in solving a hard problem like hi-res imagery from space when you can just fly one of these over the target practically at will? (With a Hellfire missile attached, no less.) Range and airspace issues notwithstanding,…

> Range and airspace issues notwithstanding

Those are precisely the reasons satellites will remain relevant. Satellites are the reason the SR-71 fell out of service. Russia can and will shoot down US aircraft or drones in their airspace.

Re: Ask HN: Which is the most powerful satellite camera directed towards earth?

#42

Post by Const-me »

o2l wrote: post #34
Const-me wrote: post #27

High-rez satellite cameras don’t film videos. Satellite cameras don’t have a 2D sensor you can find in a traditional camera. Instead, they feature a long narrow sensor. As the satellite flies over the earth, the sensor records a single row below the satellite. That row is oriented perpendicular to the satellite’s velocity. As the satellite flies, it scans a long strip of land underneath. It works similar to a flatbed…

Sorry, my bad. They used drones for that. https://www.wired.com/2011/05/with-drones-and-satellites-u-s... This article explains more about how they used a combination of satellite imagery and drones.

Yep, unlike satellites, modern UAVs can deliver a live video feed just fine.

Re: Ask HN: Which is the most powerful satellite camera directed towards earth?

#43

Post by hyperbovine »

planteen wrote: post #41
hyperbovine wrote: post #29

Earlier quoted context omitted.

Yes. There was a piece on 60 Minutes a few years back where they had a big (~20 ft. wingspan maybe), loud drone circling overhead a few thousand feet up. It was inaudible and invisible. What's the point in solving a hard problem like hi-res imagery from space when you can just fly one of these over the target practically at will? (With a Hellfire missile attached, no less.) Range and airspace issues notwithstanding,…

> Range and airspace issues notwithstanding Those are precisely the reasons satellites will remain relevant. Satellites are the reason the SR-71 fell out of service. Russia can and will shoot down US aircraft or drones in their airspace.

SR-71 is about as far from a drone as you can possibly get. Politicians are going to (pretend to) care a lot less about airspace sovereignty when violating someone else's airspace does not involve risking pilots' lives. Range and stealth are only going to increase. This is why I said the future looks bleak.

Re: Ask HN: Which is the most powerful satellite camera directed towards earth?

#44

Post by jdhawk »

astrobase_go wrote: post #13
jdhawk wrote: post #3

41cm/pixel available to the government & 50cm/pixel available to Google through GeoEye-1 https://en.wikipedia.org/wiki/GeoEye-1 31cm/pixel through WorldView-4 https://en.wikipedia.org/wiki/WorldView-4

take it for what it's worth, but according to this bbc article published in 2014... > "The latest US spy satellites, in comparison, are reported to be able to pick out objects less than 10cm (4 inches) across." http://www.bbc.com/future/story/20140211-inside-the-google-e...

Wow - I figured they were ahead, but 3x...

Re: Ask HN: Which is the most powerful satellite camera directed towards earth?

#45

Post by njharman »

palunon wrote: post #19
antognini wrote: post #11

I'm assuming this is all pretty well classified, but I would be shocked if the US government hasn't had the ability to do that for a long time. Consider that back in 2012, the National Reconnaissance Office donated two surplus telescopes to NASA that were substantially better than the Hubble telescope. If those are the sort of telescopes that the government has no need of anymore, imagine what the state-of-the-art is…

Hubble was launched in 1990, is it surprising that 22 years later, NRO telescopes are substantially better ?

The point is they were giving them away. Meaning the sats they kept are even better than better than bubble.
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