Audio FMCW
From SpenchWiki
Introduction
To demonstrate RADAR concepts without RF/an SDR, it's possible to use a sound card to generate a FMCW chirp and receive any returns. The caveat is that without special processing, it is usually not possible to synchronise the TX and RX streams in consumer audio cards.
This can be demonstrated in GNU Radio with a simple [flow graph https://github.com/balint256/gr-baz/blob/master/examples/Audio%20FMCW.grc] (and some additional visualisation blocks).
