عنوان مقاله [English]
Underwater Acoustic Tomography (AT) is a branch of remote sensing technique that transmits the acoustic waves into the water. The AT systems continuously measure the flow velocity and temperature in rivers, seas and the oceans. The AT systems are synchronized with a GPS clock (the clock is currently accurate to a few nanoseconds) connecting to the GPS Satellites. Hence, the systems transmit the acoustic waves at the same time. The systems record the arrival time of acoustic waves. After analyzing the received signals, the flow characteristics would be estimated. In the present study, the system evaluation of an AT system is investigated in the Kousar Channel, Malek-Ashtar University of Technology. Two Fluvial Acoustic Tomography Systems (FATS) were deployed on both sides of the channel. The horizontal distance between two systems was 127m. The FATS simultaneously transmitted sound pulses from the 30 kHz omnidirectional transducers every 60 seconds. The results showed that the underwater sound speed and the water temperature were 1482 m/s and 20.3 ˚C, respectively. The temperature sensor measured the surface temperature in the various points of the channel and confirmed the validity of the FATS measurement. The estimated flow velocity was zero. Due to the water stagnation in the channel, the accuracy of the velocity measurement by FATS was completely confirmed too.