Design of Attenuation loss and Multipath propagation Model for Underwater Acoustic Communication in Tank

Abstract

The wireless sensor network uses some sort of sensors to detect in general physical quantity of interest. The wireless sensor network has potential to explore difficult-to access area on the earth and the concept is extended to underwater applications in future. Past several years studies has been focused on development of reliable and robust communication systems for underwater wireless sensor network for various underwater applications. The scenario of communication is different in underwater compared to that on land as environment is completely different. Also radio waves cannot propagate for longer distance, so instead of that acoustic waves are used. The efforts are made to devise a model for acoustic frequency ranges in the environment for underwater tanks using basic equations governing various physical phenomena occurring during acoustic wave propagation. The model uses scenario of underwater tank filled with raw water diluted with sodium chloride with communicating devices placed at various distances. Attenuation model can be proposed for such communication scenario with respect to distance between transmitter and receiver for acoustic frequency ranges. The acoustic wave travelling through propagating medium suffers from multiple reflections resulting into multipath propagation. The multipath propagation model is proposed for calculation of length of multipath signals propagating in bounded shallow water. Propagation delays of each multipath signals are proposed. Empirical relationship is developed between number of multipath components and distance between transmitter and receiver. Arrival time lag jitter of various multipath signals are developed with respect to distance between transmitter and receiver and height of transmitter and receiver with respect to water bottom is also proposed.