局部置信度增强的单矢量水听器互谱方位直方图

Local confidence level enhanced cross-spectral DOA histogram of single vector hydrophone

单矢量水听器互谱方位直方图具有一定的多目标分辨能力,但其性能受到目标信号分离正交性(Window Disjoint Orthogonality,WDO)的制约。WDO特性越强,表示主导目标的能量占比越大,互谱方位估计的结果越接近主导目标的真实方位。文章提出利用局部置信度增强互谱方位直方图的多目标分辨性能。局部置信度表示样本中主成分与其他成分之间的比值关系,因此可以作为信号WDO特性强弱的估计。在统计互谱方位直方图时,利用局部置信度对时频点的方位估计结果进行加权,增加WDO特性强的时频点的方位估计结果在方位直方图中的贡献,提高目标真实方位处的谱峰,从而增强方位直方图多目标分辨的效果。湖试数据的分析表明了利用局部置信度加权能够有效提高多目标分辨的效果。

The cross spectral DOA histogram obtained by a single vector hydrophone can distinguish multi-targets to a certain extent.However,its performance depends on the window disjoint orthogonality(WDO)of target signals.The WDO indicates the proportion of the dominant signal in the total signals.The stronger the WDO,the closer the estimation of the cross spectral DOA histogram is to the real DOA of the dominant target.In this paper,local confidence level is used to enhance the cross spectral DOA histogram for multi-target resolution.Local confidence level represents the proportion of the principal component in the total components,so it can be used as an estimate of WDO.In counting cross spectral DOA histogram,the DOA estimation results at time-frequency points are weighted by local confidence levels to enhance the contribution of the DOA estimation results at the time-frequency points with strong WDO,so that the spectral peaks near the real DOAs of the targets are increased,and the multi-target resolution is improved.The analysis of lake trial data confirms the availability of local confidence weighting in improving multitarget resolution performance.