Yes, certainly not SAR. My point is there is a big heritage of space-based radar expertise the linked project is drawing on, and I was trying to choose examples that people might be familiar with. SRTM was a main source for the DEMs that people use in GIS.
http://www.timedomain.com/news/wall.php
UWB has been around for 20+ years, and IIRC there was a big patent dispute back in the late 90's.
https://books.google.com/books?id=6_XVg-nX9qgC&pg=PA7&lpg=PA...