METHOD TO MONITOR THE CHANNEL SILTATION IN REAL TIME BASED ON THE TRANSDUCER ARRAYS FIXED ON THE SIDES

摘要

A new real-time monitoring method of the channel siltation situation is presented. In this method, the emission transducer array and the receiving transducer arrays are laid out respectively on the sides of the channel with equal vertical distance. The emission transducers transmit the sonar signal of a certain frequency and pulse width. And applying double GPS high precision timing module and Programmable Logic Device (PLD), the transmission time of the sonar signal is measured. According to the transmission time, the power spectrum value of the received sonar signal and the layout of the transducers, the siltation range and thickness can be estimated. Moreover, by reducing the vertical distance between two transducers, the monitoring precision can be improved. In the anechoic tank, the baffle with sound absorbent foam was used to simulate the under-water silt environment and the experiment to monitor the siltation range and thickness was performed. The results show that when the baffle’s width and height are different, the change of the signal intensity and the transmission time is obvious. Moreover, the measuring precision and monitoring area is only related to the arrangement of the transducer arrays and is not affected by the situation of the hydrological conditions. Compared to the traditional measuring methods, the method has the advantages of low cost, excellent real-time characteristics etc.