Noise reduction in underwater acoustic signals for tropical and subtropical coastal waters

Abstract

Growing interest for underwater acoustics leads to take-up underwater applications in a commercial aspect, not only viewing it in a research aspect. This expects a good signal reception at the user end point. The received signal inherently acknowledges the high quality communication system. On the whole practicing efficient signal processing techniques for the end to end process with acceptable tradeoffs is the need of the hour. Processing the received signal is focused here which is a challenging task. Noise reduction is important in underwater acoustic signal processing. However, minimizing error does not guarantee a smooth filtering result. Using wavelet soft thresholding (STH) and time scale filter (TSF) techniques, noise reduction for the underwater signals degraded by ambient noise sources is analysed. In this work, typical noises like snapping shrimp sound and rainfall sound which can interfere with sonar and underwater communication signal causing severe degradation to the received signal is handled. Based on the typical evaluation metrics, results were compared.