Relationship between Micrometeorology and Sound Propagation above Snow-Covered and Ground Surfaces

摘要

This report summarizes measurements of sound at 24 non-harmonically related frequencies which were simultaneously transmitted over the same snow-covered and bare ground over 30, 60 and 120 m paths. Eleven frequencies each were transmitted at approx. 1/2 and 2 m height and were received on microphones positioned at the same heights at each distances. The measurements above snow were recorded on 1 and 2 February 1984, and above bare ground on a synoptically similar (from a wind speed, etc., point-of-view) day, the 26th of April, 1984. Simultaneously, a diverse set of micrometeorological measurements were recorded which would allow later analysis of the SL sound propagation medium. The multi-tone transmitters, microphone receivers and recorder were operated a total of 225 min on the 1st and 2nd of February. A total of 79 minutes of measurements were logged on 26 April. On the basis of the analyzed micro-meteorological records, the time period 13:55 - 14:18 on 1 February and 13:56 - 14:19 on 26 April were chosen for initial compare and constrast purposes. (Author)