Underwater sound propagation characteristics at mini underwater test tank with varied salinity and temperature

Abstract

In this paper, we report the development of water tank for underwater acoustic communication. Compared to most of underwater test tank, the tank may be considered as mini in term of its size. However, the test tank is intended to serve as controlled environment to develop a theoretical model and its validation experimentally before full-scale test at sea. We present on how to analyze the physical characteristics of the test tank with respect to salinity and temperature affected to speed and pattern of propagation waves. We designed the test tank made of 12mm thick of glass with dimension 2 × 1 × 1 in meter, then we placed corrugated sponges inside the walls to reduce the echo from signal that we generated. The measurements were conducted by placing array of hydrophones and analyze the propagating waves in fresh water with variation temperature 15°C, 20°C, 25°C and 30°C to simulate depth. In term of salinity we fixed at room temperature 30°C and varied the salinity of 3.1%, 3.2% 3.3%, 3.4% and 3.5%, respectively. The results showed that the sound propagation characteristics are in agreement with previous studies. This may suggest that the test tank may serve as small scale underwater acoustic experiment with controlled environment.