Calibration of echosounder using standard target method

Abstract

In this work, we develop an underwater echosounder and use the standard target method to calibrate the performance of the device. In the calibration experiments, a solid tungsten carbide sphere of 38mm diameter is used as a standard target for calibrating a HPCTB-200-35 echosounder (manufactured by Hangzhou Applied Acoustics Research Institute) with a working frequency of 220 kHz. Further, the measurement data and uncertainty are presented and analyzed; these results demonstrate that the standard target method can calibrate the combined transmitting-receiving response of echosounders effectively. In our calibration experiment, the combined transmitting-receiving response of HPCTB-200-35 is about 33.8 dB, and the measurement uncertainty is about 1.0 dB (k = 2).