H-ADCP代表流速与断面平均流速拟合精度研究

Research on fitting precision of relationship between representative velocity of H-ADCP and average velocity

水平式声学多普勒流速剖面仪(Horizontal Acoustic Doppler Current Profiler,H-ADCP)能实现流量在线监测,在其应用中,代表流速与断面平均流速的关系直接决定了H-ADCP流量测验的精度。为提高H-ADCP代表流速关系拟合精度,以小河坝水文站为例,研究了粗大误差剔除、线性回归损失函数、代表单元格选取对拟合精度的影响。结果表明:①粗大误差对拟合精度影响较大,在进行代表流速关系拟合前,需对其进行剔除;②以相对误差平方和最小作为损失函数,不仅更符合水文实际,也能提高拟合精度;③选择各单元格流速参与建立多元线性回归关系,可使H-ADCP流量测验的物理意义更加明确,并能有效提高拟合精度。

The horizontal acoustic doppler current profiler(H-ADCP)can realize real-time online monitoring of discharge.The relationship between the representative velocity of H-ADCP and the average velocity had significant effect on the accuracy of discharge monitoring.In order to improve the fitting precision,the Xiaoheba hydrological station was taken as an example,the effects of elimination of gross errors,optimization of the linear regression loss function,and the representative cell selection on the H-ADCP representative velocity were studied.The results showed that:①the gross error had a great influence on the fitting accuracy,so it was necessary to eliminate it before fitting.②The minimum sum of relative error square was used as loss function,which was in accord with the hydrological reality and can improve the fitting accuracy.③Selecting the velocity of each cell to participate in the establishment of multiple linear regression relationship could make the physical meaning of H-ADCP discharge monitoring more clear and effectively improve the fitting precision.