基于时延估计的海底线阵阵形估计方法研究

阵形估计是水听器阵列应用中的关键问题,基于时延估计的阵形估计方法比基于传感器测量和基于匹配场处理的方法具有更强的适应性和较高的精度。针对浅海水听器阵列中水平长线阵存在的纵向相关振荡现象引起的不能简单以某一阵元为基准求相对时延的问题,充分利用了阵元信号的高相关性,提出了基于子阵时延的阵形估计方法,针对子阵间时延估计误差向阵端累积的问题,该方法以时延估计的克拉美罗界为依据提出了合理的子阵方式,在一定程度上减小了误差传递。对已有海试数据阵形估计处理的结果表明,相对于单源固定间距方法和未分子阵的双源时延估计方法,基于子阵时延的阵形估计方法满足阵元间距的约束,有较好的空间谱特性,减小了阵形估计误差,对长水听器阵列的应用及阵形估计具有较大应用价值。

Estimate array shape based on time delay estimation

Applications of hydrophone arrays are limited by the error of array shapes.Array sh-ape estimation based on time delay estimation is a robust and precision method,in contrast with direct measurement using sensors and match-field inversion approaches.The relative time delay in long horizontal line arrays cannot be obtained simply by using only one element as a datum mark because of the vibration of horizontal correlations.In this paper a partitioned time delay method that makes full use of strong correlation between elements is presented for array shape estimation.It presents a reasonable method for sub-arrays based on CRLB boundary to reduce the passed error due to cumulating errors between sub-arrays and the end of arrays.Tests with data from sea trials show that the proposed method can be applied in practice compared with single source constrained by fixed inter-element distance method and double-sources method without using sub-arrays.The proposed method meets the need for distance between elements and reduces errors.It is applicable to long hydrophone arrays and array shape estimation.