Reply to: ‘‘Comments on the influence of wind and temperature gradients on sound propagation calculated with the two-way wave equation’’ [J. Acoust. Soc. Am. 9 1, 498–500 (1992)

Abstract

As shown by Pierce [J. Acoust. Soc. Am. 87, 2292–2299 (1990)], the influence of the static pressure on sound propagation through the atmosphere is only of the second order. For very accurate predictions, the improvements suggested by Raspet et al. [J. Acoust. Soc. Am 91, 498–500 (1992)] can be used, but then other second-order effects and cross products should be taken into account as well. The two-dimensional Fourier transform can be used for three-dimensional sound-pressure predictions considering the method of stationary phase. Errors are well within 2% for common temperature and wind gradients, provided that the wind vector is parallel to the vertical plane through the source and receiver. For situations with a cross-wind vector full three-dimensional calculations are recommended. These situations were avoided in the original article [Nijs and Wapenaar, J. Acoust. Soc. Am. 87, 1987–1998 (1990)].