Phased array ultrasonics[0] and Multibeam echo sounding[1] has been around for decades[2]. This project in particular is an example of what's called an air coup

Phased array ultrasonics[0] and Multibeam echo sounding[1] has been around for decades[2]. This project in particular is an example of what's called an air coupled ultrasonic phased array. It's an interesting project, but it's not first. Congrats on making it happen though, and thanks for the write up. [0] https://en.wikipedia.org/wiki/Phased_array_ultrasonics https://en.wikipedia.org/wiki/Phased_array_ultrasonics [1] https://en.wikipedia.org/wiki/Multibeam_echosounder https://en.wikipedia.org/wiki/Multibeam_echosounder [2] https://patents.google.com/patent/US5675552 https://patents.google.com/patent/US5675552