If you’re not familiar with synthetic-aperture radar (SAR) then I’d highly recommend taking a look. It’s a fascinating area of remote sensing that’s being used in a growing number of areas, particularly because it can ‘see’ through clouds and can even be used at night.
This video from ICEYE shows how SAR can be used to monitor movement on the ground, which is pretty impressive. The video is worth a watch for the visuals and soundtrack alone — it’s very Tron-like.