Study of under-water Sonar System for change in propagation speed, depth of water, bottom loss and estimating optimal PDFs

Underwater Acoustic Communication with Low Probablity of Detection(UWAC-LPD) is a significant technology, especially for military application as it helps the transmitter or receiver to stay undetected. Many studies have suggested that UWAC-LPD has comparatively low impact of marine lives as compared to traditional techniques and hence its application is extended to civilian use too. This has led to numerous research in this domain. In this work, the focus is to understand the variation of received pulses for change in propagation speed, depth of water and bottom loss. Both shallow and deep waters environments were used to send and receive the acoustic pulses. Two distinct targets in shallow water were found by an active sonar system using a rectangular waveform. The received signal showed evidence of several paths. The ‘Munk’ sound speed profile was then used to transfer pulses in deep water between a projector and hydrophone utilizing pathways created by Bellhop. The effects of spatially variable sound speed were observed.