What is the principle of a reverse radar?

[VonSerenity]

The principle of a reverse radar is: radar detectors are installed on the rear bumper or both front and rear bumpers of the car to detect obstacles in the front and rear, helping the driver to see obstacles around the vehicle or the distance to other cars when parking. In addition to facilitating parking, this device can also protect the car body from scratches and improve driving safety. The full name of the reverse radar is reverse anti-collision radar, also known as a parking assist device. It is a safety assist device for car parking or reversing, consisting of ultrasonic sensors, a controller, and a display, among other components. The reverse radar also has certain blind spots, including obstacles that are too low, too thin, or ditches.