Reverberation-Derived Scattering Strength of the Shallow Sea Bed

Abstract

Measurements of explosive reverberation level and transmission loss have been made at a location off the west coast of Florida in water 200 ft deep. The measurements were reduced to scattering strength by means of a simple formula that ignores the details of the propagation paths to and from the scatterers. These reverberation-derived scattering strengths are found to be comparable to those previously measured for the deep sea bed. In addition, the reverberation tails of off-set sources, displaced by distance up to 5 miles from the receiving hydrophone, are found to be identical to the reverberation tail of a nearly source when time-shifted by the travel time from source to hydrophone. Although no direct scattering measurements on the shallow sea bed were made, the agreement of the reverberation-derived scattering strengths with the known scattering strength of the deep sea bed suggests the validity of the simplified model and its possible value for reverberation prediction, so as to make it analogous to the various existing prediction models for shallow water transmission.