Received Pulse from an Aerial Ultrasonic Sensor Affected by Temperature and Relative Humidity

Abstract

In order to develop an aerial back sonar for a car, we predicted the waveforms of the received pulse calculated by the finite-difference time-domain (FDTD) method. The echo pulses reflected from the obstacle were calculated as a function of the object's height, the changing temperature and relative humidity in air. The maximum amplitudes of received pulses were changed by about 25% by the variation of relative humidity. The increase of temperature enlarged the variation of amplitudes on received pulses. The result shows that we need to consider the effect of the variation of temperature and relative humidity on an aerial back sonar.