Correlation between excess attenuation and geometric or meteorological parameters

Abstract

Extensive experimental measurements of sound propagation and vertical sound‐speed profiles over level agricultural terrain are presented. A high‐power speaker generating pure tones at approximately one‐third octave band center frequencies from 160–4000 Hz was used as the noise source. Sound levels were measured and recorded at ranges of 2, 125, 250, and 500 m from the source during various time periods of interest from 3–7 July 1990. Simultaneously, meteorological conditions were measured using a variety of tower mounted anemometers and temperature sensors. A total of 50 sets of 10‐min averaged data at each of 12 frequencies and 4 ranges was obtained. Temperature and velocity profiles were reconstructed using Monin‐Obukhov scaling theory. A statistical regression analysis to determine the correlation between excess attenuation and measurable geometric and meteorological parameters was completed. Sample measurements are presented and comparisons are made to the Daigle model [J. Acoust. Soc. Am. 65, 45–49 (1979)].