Analysis of backscattering data in the Tyrrhenian Sea

Abstract

Research has been conducted in the Tyrrhenian Sea basin to measure low-frequency basin reverberation and relate the measurements to backscattered strength. The receivers were a towed horizontal array and a suspended vertical array. Standard Italian Navy depth (74 kg) and SUS (0.818 kg) charges were used as sources. The unique factor in this broadband basin reverberation experiment was that data were collected simultaneously from the horizontal and vertical array. Towed-array data were taken on multiple headings; combining different headings permitted removal of the ambiguous directionality information from the towed array. Frequency-domain beamformed data are presented and reveal that, in the area examined, basin features are the strongest backscatterers. Receiver beam level data are presented primarily for 300 Hz, but some data are given for 100, 450, and 730 Hz as well. Estimates of backscattering strengths of different features are provided and are in the range quoted in other publications. A comparison of the horizontal and vertical array scattering strengths estimated for some selected basin features is also included. Statistics for the dominant backscatterers are given, and the results from one basin feature are presented showing detailed backscatter structure.