Comparison of speed over ground estimation using acoustic and radar Doppler sensors

This paper deals with an automotive Doppler ground speed measuring system. Doppler sensors provide a contactless way of measuring speed, which recieved great interest in past decades and with recent technological improvement has become readily available for commercial purposes. One of the key problems for speed over ground measurement is the true speed estimation from the spread spectrum due to sensor beam width. In this paper, after a discussion of the basic principles of vehicle speed-over-ground, an alternative fast but effective Doppler estimation algorithm is used to estimate and compare the accuracy of speed estimation at various speeds for a 24 GHz radar and a 40 KHz acoustic experimental Doppler system. The results also show that radar system can always provide a reliable and accurate speed measurement. However the acoustic may not be capable of high speed measurement, depending on the accuracy required.