The influence of beam angle on Doppler frequency measurement result
The uncalibrated results of acoustic Doppler velocity measurement equipment with different beam angles are deviated.The influence of beam angle on the result of acoustic Doppler velocimetry is studied,in which underwater ellipse scattering model is adopted,and the conclusion is of practical significance to improve the performance of acoustic velocimetry measurement.When the ellipse scattering model is adopted,there are differences in propagation loss and scattering intensity from different directions,which result in asymmetric spectruman and small frequency measurement results.Using the asymmetry coefficient to quantify the degree of spectrum asymmetry,if the beam angle increases,the azimuth asymmetry coefficient increases,which leads to the growth of the frequency deviation.Besides,the expression of frequency measurement deviation caused by beam angle is derived.By analyzing the frequency measurement results of simulation and field test data,it can be seen that the frequency measurement deviation under different Doppler frequency shifts is consistent with the calculated value of the formula,and the actual frequency measurement deviation under different beam angles increases with the increasing beam angle.
NETL
NSTL
万方数据
维普
