声学多普勒流速剖面仪(Acoustic Doppler Current Profiler,ADCP)对河流进行流量测量时,ADCP一般采用底跟踪模式(以河底为参考系)获得流速、断面面积,进而获得当前流域的流量,但当河流存在大量走沙("动底")情况时,底跟踪速度缺少顺水流分量,致使底跟踪轨迹向上游偏移底跟踪速度偏小,进而导致流量偏小.文章通过对动底原理进行分析、对动底测量方法中的回路法进行研究,提出一种基于GGA的全球定位信息系统(Global Position-ing System,GPS)模式下平均动底速度测量方法以及两种动底流量补偿方法,并利用实测数据进行分析验证,结果表明本文提出的动底速度测量方法及动底流量补偿方法对"动底"检测与补偿有显著的效果.
Discharge compensation algorithm based on ADCP"moving bottom"measurement
In the discharge measurements of the river,the acoustic Doppler current profiler(ADCP)generally adopts the bottom tracking mode(i.e.taking the river bottom as the reference system)to obtain the discharge velocity and cross-sectional area and then to obtain the discharge of the current watershed basin.But,when there is a large amount of sediments in the river,the"moving bottom"appears,therefore the bottom tracking velocity lacks the downstream component to cause the bottom tracking trajectory shifting upstream,and so the bottom tracking velocity is small,resulting in a small flow.In this paper,the principle of moving bottom is analyzed and the"loop method"in the dynamic bottom measurements is studied,and then a measurement method of average dynamic bottom velocity based on global positioning system fix data(GGA)mode and two moving bottom flow compensation methods are proposed.Through the analysis and verification of the measured data,the results show that the moving bottom velocity measurement method and the moving bottom flow compensation method proposed in this paper are significantly effective for"moving bottom"detection and compensation.
acoustic Doppler current profiler(ADCP)moving bottombottom trackingdischarge compensation
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