Methodologies for broadband reverberation data processing and analysis

摘要

Data processing methodologies used to analyse broadband reverberation signals from an explosive sound source are presented in this paper. Reverberation data was collected at deep (2070 m) and shallow water (57 m) sites in the Bay of Bengal. In these experiments, TNT charges (0.450 kg) were used as sound sources. The received signals were recorded using two hydrophones deployed from the ship. The sonic surface duct thickness at the shallow water site is around 32 m with a limiting ray angle of 3.16 degrees and a lower cut off frequency at 416 Hz. The deep water location had deeper duct (63 m) with a limiting ray angle of about 4.47 degrees and a lower cut off frequency of 177 Hz. One third octave band analysis using multirate filters and time frequency analysis were used to study the reverberation characteristics. Comparison of deep water and shallow water reverberation characteristic across a broad band of frequencies are presented along with analysis based on ray modelling.