Ultrasonic, infrared, laser, and microwave devices can be used for distance measurement. The time for a pulse of energy to travel to an object and be reflected back to a receiver is measured, from which the distance can be calculated, i.e.,
Ultrasonic, infrared, laser, and microwave devices can be used for distancemeasurement. The time for a pulse of energy to travel to an object and be reflectedback to a receiver is measured, from which the distance can be calculated, i.e.,