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Comment by sandworm101 | Hacker News Reader

Satellite images are to drone footage what Poleroid is to 4k hdr. Both are images but that is where all practical similarity ends.

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Also:

Drones fly under the clouds.

And:

If you've subverted the drone imaging you can use it to hide stuff.

If you've subverted drone control you could use it as an active agent in conflict.

What evil things can you do with 4K HDR images of crops that you couldn't do with what's on google maps satelite view?

You can get way higher zoom/detail from cheap drones compare to GoogleMaps:

https://www.mobiddiction.com.au/wp-content/uploads/2019/12/D...

You can use stereoscopy from overlapping drone images to get depth maps:

https://www.mobiddiction.com.au/wp-content/uploads/2019/11/T...

I have no doubt major world powers have satellites that can match and exceed those sorts of capabilities from space, instead of from 100m up, but if you can get end users to pay for it themselves, why the hell wouldn’t you take it.

(Note, that was a DJI drone, and I would have no real surprise if the Chinese couldn’t have taken all my imagery if they’d wanted to. I _might_ have noticed them exfiltrating a few 10s of GB of data somehow, but I might not have as well… They are already geo fencing every single flight it makes, to trigger a warning and ensure I can’t fly over airports (or out the front of my house, since I’m only a few km out one on the flight path from my local airport). I’d hardly be surprised if the drone triggered some other action if someone chose to fly one near/over a nuclear reactor or a military base…

Also think of angles. At 100m your drone is looking down, in basically the same direction as a satellite. But during those few seconds when you takeoff/land your camera is probably pointing sideways, a perspective that a satellite cannot replicate. Rather than simply a higher resolution, those few seconds at low altitudes give a very different perspective on an object. If you want to see the underside of a bridge, to determine if its support can handle tanks, you won't get that information looking down from 100m. You will get it looking sideways from 2m.

You can get much better detail from drones if the drone happens to be pointing at what you're interested at in a time frame you're interested in. And, as you point out, if they can get the GB of data back.

China has access to better Earth Observation resources than Google Maps anyway, so a collection of EO imagery from tasked satellites of different types up to 0.25m pixels of something they actually want to monitor when they want to monitor it is a lot more useful than even higher resolution image collections of some random farm at random times. The latter wouldn't be entirely useless for intelligence purposes if the backdoor exists, but neither is Googling for images of locations voluntarily uploaded to the public web by smartphone users...

Determine whether that crop field is firm enough to support a tank driving over it. Or whether a helicopter can land on it without getting stuck. Or whether the crop is dry enough to catch fire. Or is the crop high enough to mask troop movements. And that is just the field. The nearby hedgerows, roads and other infrastructure is a big deal too.

The hedgerows of France! The allied forces greatly underestimated how difficult it will be to travel through them during WWII.

Because of American planners. The age of the oldest hedge in the US is measured in decades. Hedges in France are aged in centuries. American tanks thought they were driving though some bushes. They ran into oak trees.

Are you sure about this, or just speculating?

Definitely not the case for US DoD / NRO satellites.

I wonder how long this will be true. Right now I think the US has 10cm/pixel resolution, but I imagine it's not long before that is far better? It might already be, we just wouldn't know about it

We got the Hubble after they made spy satellites about the same size. Maybe there is the equivalent of the JWST looking down at us?

JWST would be totally useless as a spy satellite. It sees in IR. It is in space specifically because IR does not penetrate the atmosphere very well. That applies when looking down equally as up. Everything from the mirror and sensors to the entire cooling operation is optimized to see that IR blocked by earths atmosphere. So any spysat version wanting to actually see through that atmosphere would share almost nothing in terms of design or parts.

This is what real spysats looks like. They make JWST look like a toy.

https://en.wikipedia.org/wiki/Orion_(satellite)

"is according to NRO director Bruce Carlson "(...) the largest satellite in the world".[3] It is believed that this refers to the diameter of the main antenna, which might be well in excess of 100 m (330 ft)."

I think its kind of amazing how little is known about Orion. Not even the manufacturer is publicly known.

Impressive job keeping secrets.

Its not only in space, but very far away from the Earth and the Moon, so it doesn't become saturated with IR. That apart, there is a lot of important IR a spy satellite would search for. The heat signature from a fighter jet is much larger that its visual signature, for example.

IR is how satellites see clouds at night. Seems to work pretty well.

Weather-related sats see the clouds because IR is blocked by moisture, the stuff that clouds are made of. Spy sats generally want to see things that are not made of water.

Yawn. https://www.usgs.gov/special-topics/water-science-school/sci...

Depends? Humans are made out of water (mostly) ;->

Orion is a spy satellite for radio frequencies ("sigint satellite"). While it is massive, it's not an optical spy satellite and certainly does not have <10cm resolution.

JWST is fairly old tech now so probably better - by better I mean in some colloquial sense based on the passage of time, i.e. JWST would be pretty useless pointed at the earth one imagines.

Pointed at earth from k2 it would be useless.

But a similar diameter in the same orbit as current spy satelites may be able to resolve objects 1/3 of the size. If OP is correct about 10cm, that would place it at around 3.7cm.

It still is incredibly poor compared to what a high flying aircraft could capture, much less a drone spraying chemicals.

There are other considerations. The atmosphere is wobbly. You can have a mirror 100f across. That won't help the distortion. The only option is active optics, mirrors that adjust in real time, something very hard to on the ground let alone in space.

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