A New Satellite Can Peer Inside Buildings, Day or Night • Hacker News Board

Re: A New Satellite Can Peer Inside Buildings, Day or Night

#61

Post by Someone1234 » Thu, Dec 17, 2020, 4:17 PM UTC

sq_ wrote: post #52

SoapSeller wrote: post #45

Earlier quoted context omitted.

It doesn't looks like SAR to me(there are shadows, for example). More like standard optical image(the resolution and details are amazing, if it's a satellite, which is doubtful given the angle).

IIRC, the conclusion at the time was that that particular image was taken by an NRO KH-11 satellite - roughly equivalent to a Hubble Space Telescope pointed at earth and definitely not SAR.

Supposedly this was taken by a KH-11 Block 4 (USA-224) which means this is cutting edge as of 2005. We're currently on Block 5 as of 2018.

The biggest secrets within US Reconnaissance Satellites isn't really optical clarity anymore, it is their capabilities in other spectrums (and have supported at least infrared for 30+ years, but with signals intelligence well beyond that since).

Re: A New Satellite Can Peer Inside Buildings, Day or Night

#62

Post by hungryforcodes » Thu, Dec 17, 2020, 4:21 PM UTC

heyflyguy wrote: post #4

This is cool tech and there are new players entering this field with even better capability. The Clinton era laws of optical resolution restrictions seems silly now with this tech in the commercial marketplace.

I'm not really sure what is so cool about this. It seems incredibly invasive.

Re: A New Satellite Can Peer Inside Buildings, Day or Night

#63

Post by asdfadsfgfdda » Thu, Dec 17, 2020, 4:39 PM UTC

px43 wrote: post #14

I'd bet someone could pretty easily build an alarm that goes off every time one of these things is looking at you. That radar blast has got to be massive. This definitely couldn't be a 24/7 thing from those satellites. I wonder how much radar time one of those things has before it needs to recharge/refuel.

Or just track the orbits, these are all published by NOARD. Most satellites do not change orbits often.

Even easier, Capella-1 is in a sun synchronous orbit, so it will always pass overhead at the same local time, at noon or midnight.

https://www.n2yo.com/satellite/?s=43791

Re: A New Satellite Can Peer Inside Buildings, Day or Night

#64

Post by mrtnmcc » Thu, Dec 17, 2020, 4:42 PM UTC

>> Satellite can peer inside buildings

Looking at the examples of 'ghostly buildings', it seems these are just combining different perspectives as the satellite moves. It isn't actually seeing inside the building, just 3D rendered to look transparent.

10Ghz has (optimistically) a building penetration loss of 25dB [1], with any reflections back also seeing 25dB loss. I don't think this is workable with current satellite power flux density regulations. At least not at 10Ghz.

[1] ITU-R P.2346-1 https://www.itu.int/dms_pub/itu-r/opb/rep/R-REP-P.2346-1-201...

Edit: the claims to seeing 'individual rooms' are not backed by any examples, but maybe natural corner reflectors could rarely give a return. Still wouldn't be able to see anything within the room.

Re: A New Satellite Can Peer Inside Buildings, Day or Night

#65

Post by karmakaze » Thu, Dec 17, 2020, 4:44 PM UTC

> “There’s a bunch of gaps in how we’re currently observing Earth from space [...]”

It's weird to hear places that were expected to be private to be called 'gaps' like they should be visible but weren't until we had the technology to fix that.

> Capella launched a platform allowing governmental or private customers to request images of anything in the world

'or private customers' adds to the looming creepiness of our future.

Re: A New Satellite Can Peer Inside Buildings, Day or Night

#66

Post by walrus01 » Thu, Dec 17, 2020, 4:46 PM UTC

leoedin wrote: post #20

motohagiography wrote: post #9

In the 9ghz range, does that mean a sub-1mm wire mesh could mitigate this? Asking for a hypothetical house renovator friend. Thompson's adage of when the going gets weird, the weird turn pro suggests that the tinfoil hat crowd could be able to corner the emerging domestic Faraday cage market.

If you want to block SAR, just set up a big corner reflector near you. It'll completely blind the part of the image near you. It would also draw a lot of attention to you... So maybe not the best approach if you're trying to hide.

or a whole bunch of small corner cube reflectors (such as you would see attached to a sailboat mast for intentional greater radar visibility) in a grid like array.

https://www.westmarine.com/WestAdvisor/Selecting-a-Radar-Ref...

Re: A New Satellite Can Peer Inside Buildings, Day or Night

#67

Post by giantg2 » Thu, Dec 17, 2020, 4:59 PM UTC

credit_guy wrote: post #28

choeger wrote: post #12

Combine this technology with the launch cadence and pricing of SpaceX and the implications are astounding. First of all, security. If your opponent has that kind of capability, you cannot meaningfully deploy tanks or any other vehicles anymore. Even infantry will suffer massively once the resolution goes up a notch. On a much smaller level, one could easily detect brake-in attempts on unguarded property. Second, indu…

> governments [...] could easily inspect "their" people Governments can now spy on their people via old fashioned surveillance: wire-tapping, informants, social media analysis, etc. If a nation has the checks and balances to prevent that, then it's very likely they'll be able to prevent satellites peeking into your home. If not, it could potentially be another tool in their oppression toolkit, but not terribly effici…

There may not be specific laws preventing this sort of surveillance because it is unknown. Sure, you could have it considered as a general 4th ammendment violation which would protect the general population. You'll still have it used against small numbers of high-value targets.

I think the main thing preventing widespread use is that once you start using these technologies on a larger scale, then people can identify it's capabilities (making it less effective, especially against the highest value targets) and also creating public backlash once a sufficient number of 'normal' people have been targeted (without getting 'disappeared').

Re: A New Satellite Can Peer Inside Buildings, Day or Night

#68

Post by giantg2 » Thu, Dec 17, 2020, 5:07 PM UTC

asdfasgasdgasdg wrote: post #26

choeger wrote: post #12

Combine this technology with the launch cadence and pricing of SpaceX and the implications are astounding. First of all, security. If your opponent has that kind of capability, you cannot meaningfully deploy tanks or any other vehicles anymore. Even infantry will suffer massively once the resolution goes up a notch. On a much smaller level, one could easily detect brake-in attempts on unguarded property. Second, indu…

I thought tanks and infantry were already basically done against equiv-tech opponents. They are not sufficiently mobile to dodge the various smart weaponry we have available today.

As those offesive technologies advanced, so too have the countermeasures.

Another part is that you have equal-weight matchups occurring at each level. Your expensive and highly capable platforms will be busy targeting the adversarial platforms that pose the most threat to them (usually expensive systems as well), leaving less time/resources to commit to the lower weight targets. For example, you're not going to get as much air support from either side if the planes are dealing with each other.

Of course that is highly generalized as the whole system works as an interdependent mesh.

Re: A New Satellite Can Peer Inside Buildings, Day or Night

#69

Post by rademacher » Thu, Dec 17, 2020, 5:12 PM UTC

SAR has been around since the 70s and works using the same principles as CT scans (projection slice theorem). Think about observing an image by rotating it and projecting it orthogonally to the rotated direction. Take a bunch of these measurements (basically a radon transform) and then you can invert the process using the back projection algorithm.

The resolution of the image is proportional to the bandwidth of the waveform and the distance traversed by the satellite during the collection process.

This article is a bit of an exaggeration and Capella is certainly not the first or only SAR service.

Re: A New Satellite Can Peer Inside Buildings, Day or Night

#70

Post by aerostable_slug » Thu, Dec 17, 2020, 5:13 PM UTC

geomark wrote: post #5

lemonspat wrote: post #2

The DoD (or the NRO) had this tech in the 80s? Wasn’t this SAR originally in the form of ground penetrating radar invention for finding nukes in ground siloes?

Also used to track submerged submarines by detecting ocean surface disturbances caused by the underwater wake of the submarine. Same benefits: works at night and through cloud cover.

Tracking submerged boats from space is the holy grail of ASW, and as best as I can tell it doesn't work outside littoral zones (where sometimes you can optically detect the sub) and contrived tests. It has been tried with SAR, blue/green lasers, IR, all kinds of stuff, and luckily it doesn't work in the real world.

When it does, it will be massively destabilizing as it places the "invulnerable" second strike capability that guarantees deterrence against peer states at risk.