The acoustic sounder : pollution fighter's tool

A measurement of the depth of the mixing layer is shown to be an important parameter in understanding and dealing with the air pollution problem. A model is proposed which uses this measurement and surface wind measurements to provide a good approximation to the ventilation rate. The pure acoustic sounder (PASS) is capable of measuring the depth of the mixing layer by measuring the height and thickness of inversions and the height to which convections extend. The acoustic sounder continuously monitors this depth, even through smog, fog,or low clouds and thereby provides constantly updated information as well as information on the time rate of change of this depth.