宽带声学多普勒流速剖面仪球面散射回波模型研究

宽带声学多普勒流速剖面仪通过处理水下体积回波信号进行流速估计,回波模型的准确度决定了理论仿真的正确性。针对回波的散射特性,通过分析水层回波信号的时空关系,提出一种球面散射水层回波模型,并利用坐标旋转方法推导出该水层回波解析式。相比其他方法,该模型解析式充分体现了散射体模型形状对回波的作用,更加接近实际情况。对该模型下回波信号进行频谱和自相关特性分析,采用复相关算法估算流速。通过与实测数据进行对比,结果证明了该回波信号模型与解析式的正确性。

Research on Spherical Scattering Echo Model for Broadband Acoustic Doppler Current Profiler

The broadband acoustic Doppler current profiler estimates current velocity by processing underwater volume echo. The accuracy of the echo model decides the correctness of theoretical simulation. According to the scattering characteristics of echo, a spherical scattering model was proposed through analyzing the space-time relation of echo. Using the coordinate rotation method, the analytical formula of echo was derived. Compared to other methods, the formula fully reflects the effect of scattering model shape to echo and matches reality more exactly. The spectrum and autocorrelation feature of the echo model were analyzed, and the current velocity was estimated by employing the complex self-correlation algorithm. By comparison with the measured data, the results show the echo model and analytic formula are correct.