This guy has been working on their own SAR drone for a while, just had another really nice blog post. Definitely looks like it weighs <10 lbs. He post-processes, but I doubt that's that hard to rework.
https://hforsten.com/interferometric-synthetic-aperture-rada...
It looks like a DIY implementation of some of the commercial land surveying SAR payloads that companies will sell you (for $60,000) to fly below a DJI M400 or similar size craft for tasks like monitoring open pit mines, etc. Also not realtime data return over RF data link, it's a download and post-process workflow.
