声学悬浮泥沙观测数据现场定标研究

In-situ calibration of acoustic measurement of suspended sediment

用声学设备探测水体中悬浮泥沙浓度及其变化的关键问题是对观测数据进行标定。通过分析在长江口海域现场观测得到的声学后向散射强度数据和水样泥沙实测值，提出了三种将声学观测数据转换为泥沙浓度的现场标定方法。结果表明，采用特征时刻标定所得数据与实际值相比离散性较小，统计误差约为２０％。该方法比同步采水标定更为简便实用。

The key to the problem of probing the concentration of suspended sediment in water and its vari- ation with acoustic equipment is how to calibrate the obtained data. Combining the acoustic backscatter inten- sity data with the real concentration of suspended sediment from water samples collected from the Changjiang River Estuary, three in-situ calibration methods for transforming measured sediment are induced. Results show that the discrepancies between calibrated values given by characteristic times calibration and real ones are less than the values given by single shot method, and the statistical error is 20% approximately. Calibra- tion on characteristic times can be more simple and practice than synchronic calibration.