It’s highly likely that Tesla compared the results from ultrasonic sensors and cameras and used them to calibrate Tesla Vision for distance measurements.

An evaluation kit from TDK showcases its USSM1.0 PLUS-FS ultrasonic sensor module for designs requiring obstacle detection and distance measurement.

Shenzhen Dauxi Vision Technologies develops sensors that measure distance using ultrasonic waves. The sensors can determine whether there is an obstacle in the path of a robot to prevent collisions.

New findings show that Tesla will offer parking distance measurements for cars without ultrasonic sensors using Tesla Vision with the 2022.45.11 software update ...

Ultrasonic range-finding sensors can measure the distance between workers with centimeter accuracy and alert those who are within minimum distance limits.