A parametric study of long-range atmospheric sound propagation using underwater acoustics software

Abstract

In the context of a research on the measurement of long-range attenuation of noise from terrestrial sound sources, a parametric study of atmospheric sound propagation channel characteristics as a function of source height, ground characteristics and meteorological conditions is presented in this paper. The study relies on ray-tracing. The Bellhop ray tracing model which is well known in underwater acoustics has been used here. In this paper, the accuracy of Bellhop’s predictions in the atmosphere is first addressed by comparison with results from Salomons’s ray model and published benchmarks cases by Attenborough et al. No significant discrepancy was noticed with respect to these references. The second part of the paper presents a parametric study for source heights ranging from 0.05m to 200m, a grid of receivers at ranges between 200m and 2km from the source and between 2m and 50m height. A homogeneous flat absorbing ground described by a complex reflection factor is assumed. For the atmospheric conditions, a subset of five different classes in the wind and stability classification from ISO-standard 1996(2)2017, was considered. The results are analyzed from the point of view of the receiver and discussed in terms of attenuation, number of arrivals and number of reflections.