However, the claim that this is "based on technology used to detect alien life on distant exoplanets" sounds dubious. Exoplanets are far too distant to use radar on them at all, let alone pick up alien life signs.
I would think the technology in question is a sensitive detector. In that case, it could work either passively for the exolife search, or in an active SAR situation.
I don't know where they got "exoplanets" from. I Googled a bit and the best [0] I could find indicates some connection to radar tech used on missions like Cassini's.
First thought was that it's likely a signal processing technique designed to pick out a periodic signal in noisy data which allowed them to pick up out the heatbeats. To me that doesn't seem like much of a leap, but I don't know what they actually did.
