宽带多普勒计程仪速度解模糊方法研究

Solution to velocity ambiguity of broadband Doppler velocity log

为了解决宽带多普勒计程仪在较高速度下存在的速度模糊问题,建立了宽带多普勒计程仪的回波模型,分析了回波的自相关特性。在不改变系统结构的基础上,提出了采用回波自相关的第1个峰值位置的方法确定速度范围,并与复协方差方法结合实现无模糊地估计速度,从而解决测速模糊问题,同时提出采用三点相关插值算法估计自相关峰的位置。最后采用湖试数据分析和数字仿真证明了这种解模糊方法的有效性。

To solve the problem of velocity ambiguity under high speed in broadband Doppler velocity log,an echo model of broadband Doppler velocity log was established,and the autocorrelation characteristic of echo was analyzed.A solution to velocity ambiguity is proposed,which does not change the structure of Doppler velocity log.The velocity can be estimated unambiguously using the first peak of autocorrelation of echo;and the velocity range is decided,which is combined with complex covariance method and the velocity can be measured unambiguously,thus velocity ambiguity is solved.At the same time,a method of three-point interpolation of correlation for estimating the first peak of autocorrelation is proposed.Analyses of lake experiment data and digital simulation prove that the proposed solution to velocity ambiguity is effective.