Backscattering of sound by nonlinear interaction in gas media and its possible application to a remote sensing acoustical probe

Abstract

We consider the non-linear interaction of non-collinear acoustical waves in gas media. Conditions for the resonant backscattering are formulated in analogy with the four-wave mixing known in optics. The efficiency of the phase-matched interaction is calculated in the resonant approximation for gas media. The possibility of using the resonant backscattering as a remote acoustical probe in the atmosphere is analyzed. It is found that for acoustical waves with wave number 10 m-1, sources of size 1 m, and a distance to the interaction region of 100 m the amplitude of the reflected wave can be larger than 10-10 times the atmospheric pressure.

Keywords

• resonant backscattering
• acoustical waves
• resonanz-rückstreuung