Characteristics of underwater acoustic channels in SAS and evaluation of the impact of acoustic wave absorption on echo signal structure

Characteristics of underwater acoustic channels in SAS and evaluation of the impact of acoustic wave absorption on echo signal structure

연구 분야: Infrastructure

학회: Signal, Image and Video Processing

Signal processing in sound navigation and ranging (Sonar) systems is a highly intricate process that necessitates the integration of multiple input parameters to achieve accurate underwater imaging. Among these, the characteristics of the acoustic propagation channel play a pivotal role in determining the quality of the Sonar images. This paper focuses on analyzing the critical properties of underwater acoustic channels that influence the signal processing in Sonar, including the speed of sound propagation in water, the Doppler shift effect, the attenuation of acoustic signals during propagation, and the phenomenon of multipath interference. This paper develops a mathematical model of the echo signal, incorporating the frequency-dependent characteristics of acoustic wave absorption in water. As this absorption varies with frequency, linear frequency-modulated signals undergo significant distortion at the receiver. Simulation results demonstrate that, for a carrier signal with specified frequency and chirp rate, the received signal spectrum exhibits distortion with a noticeable deviation.