Connection between acoustic and electromagnetic sea‐surface backscatter

Abstract

The performance of active high‐frequency acoustic systems operating under water is, in many cases, limited by backscattering from the sea surface. The strength of surface reverberation has been experimentally found to depend on the speed of the wind driving the ocean waves, while the Doppler spread of the scattered signals has been related to the waveheight. Electromagnetic sea‐surface backscatter may be used to remotely sense the ocean surface and, hence, provides a means of empirically predicting the properties of acoustic reverberation. We investigate the relationship between acoustic and electromagnetic surface backscatter. The physical mechanisms responsible for acoustic backscatter are discussed and the extent to which the relevant oceanic parameters may be extracted from electromagnetic backscatter data is assessed. It is concluded that electromagnetic remote sensing of the ocean surface provides a viable means of predicting both the strength and Doppler characteristics of underwater reverberation.