The idea of doing a spectrum recording and having something else process it in non-real time was actually used for Mobile Assisted GPS used to locate mobile phone users ringing emergency services.

Iirc it was a stopgap measure to improve cell tower location without requiring handsets smart enough to process GPS or that didn't have enough time to get a fix. It's briefly mentioned in Wikipedia though details are scant: https://en.m.wikipedia.org/wiki/Radio_resource_location_serv...