How does a Rangefinder Work - Physics of Probeware
Introduction to Rangefinders
Rangefinders, sometimes called motion sensors or motion detectors are commonly used in probeware, camera autofocus, and robotics. Rangefinders operate on the principle of a time-of-flight measurement and consist of a transmitter and receiver. The transmitter emits a signal (ultrasonic or optical) then the receiver detects the reflection or echo of the signal. The amount of time between transmit and receive is called the time-of-flight and is used to calculate the distance to the reflecting object: