All the hardware and software are open-source and available on GitHub. We covered another ultrasonic anemometer a few years ago, but it had a different sensor arrangement.

Qian Y, Han S W, Kwon H J. Design of an ultrasonic concentrator for vibro-tactile sensors using electro-mechanical analogy [J]. International Journal of Precision Engineering and Manufacturing, 2019, ...

Ultrasonic Fingerprint Sensor Using a Piezoelectronic Micromachined Ultrasonic Transducer Array Integrated with CMOS Electronics. Applied Physics Letters, 2015 DOI: 10.1063/1.4922915 ...