[craftinator]

Look into the physics of how this technology works. If you do that, and take the time to grok it, you'll have the information to understand that this type of radar cannot penetrate any of the materials that buildings are made.

[andi999]

10 Ghz is used in ground and wall penetrating radar

[jcims]

That's the disconnect here I think.

SAR is a technique for building up a two dimensional image by rasterizing one dimensional signal reflection data. Any type of radiant energy would presumably support SAR techniques, from sonar to x rays, although the 'R' in SAR presumably limits it to radio frequency range (~30Hz-300GHz). Some of which, as I mentioned originally, absolutely would see through buildings.

My point is that the headline and article are trying to make the case that 'SAR can't see through buildings', when it should be 'Why it looks like our satellites are seeing through buildings' because that is all that is explained.

[andi999]

Yes. And actually I wouldnt be surprised if their satellites actually can see through buildings (because the frequency band they use should allow that). Maybe just need to adjust the color-scale (or switch to logarithmic if it is not). I mean 10GHz SAR is capable: https://www.kurzweilai.net/seeing-through-walls-in-real-time (of course SNR might be too low for satellite, but this is nowhere written)