基于频偏应答的ADCP流速现场校准方法研究

针对声学多普勒流速剖面仪(ADCP)现场校准困难的问题,介绍了一种基于频偏应答的ADCP流速现场校准方法。通过声信号应答器,设置回发信号相对于发射信号的频偏实现速度矢量的模拟,并以频率为溯源量,对ADCP发射的信号及应答器回发频偏信号进行频率校准,进而实现ADCP流速参数的现场校准。研制了一套基于频偏应答的ADCP流速现场校准装置,在实验室消声水池条件下,以四波束300kHz ADCP为校准对象,开展了1～2m/s的流速校准实验,进行不确定度分析。结果表明,该装置对流速校准的不确定度达到1％模拟流速＋7mm/s,验证了该校准方法的可行性。

Research on Field Calibration Method of ADCP Velocity Based on Frequency Offset Response

With the regard to the difficulty in field calibration of Acoustic Doppler Current Profiler( ADCP),a field calibration method of ADCP velocity based on frequency offset response is introduced. Through the acoustic signal transponder,the frequency offset of the back signal relative to the transmitted signal is set to simulate the velocity vector,in addition,frequency is taken as the traceability quantity to carry out frequency calibration on the signals emitted by ADCP and the offset signals sent back by the transponder,so as to realize the field calibration of the velocity parameters of ADCP.A field calibration device of ADCP velocity based on frequency offset response is developed. In the laboratory anechoic tank condition,four-beam 300 k Hz ADCP was used as the calibration object,carried out a velocity calibration experiment of 1 to2 m/s and performed uncertainty analysis. The results show that the uncertainty of the flow rate calibration is 1% simulated flow rate + 7 mm/s,which verifies the feasibility of the calibration method.