Surface Backscattering Strengths Measured over an Extended Range of Frequencies and Grazing Angles

Surface backscattering strengths were measured in octave bands, using explosive sound sources in an experiment similar to that reported by Chapman and Harris [J. Acoust. Soc. Am. 34, 1592–1597 (1962)]. In the earlier experiment, measurements were made in the frequency range from 400–6400 cps and at grazing angles up to 60°. In the present experiment, a wider band of frequencies was covered, 100–6400 cps, and the maximum grazing angle was increased to 80°. Where results could be compared, the scattering strengths in the two experiments were in general agreement, any differences being consistent with the observed differences in ocean swell.