DISTANCE MEASURING APPARATUS AND METHOD

摘要

A distance measuring apparatus and method using an acoustic signal. It includes a transmitting probe for transmitting an acoustic signal from a transmitter, a plurality of receiving probes having resonance frequencies different from the central frequency of the signal transmitted from the transmitting probe, and a control circuit for controlling the functions of those probes. The acoustic signal is received by a receiving probe having a resonance frequency which provides the maximum received-signal sensitivity at the central frequency of the received acoustic signal under the control of the control circuit to thereby measure a long distance accurately.