单矢量传感器的互谱估计与方位估计

Cross spectrum and DOA estimation based on a single vector sensor

单矢量传感器的互谱估计,将时域随机过程变换成了频域随机变量.该变量的统计特性,使得各向同性噪声场影响具有更加明确的物理解释.给出了互谱估计一、二阶矩和一维概率密度函数.由于拾取了振速信息,单个矢量传感器便能获得目标方位的最大似然估计.基于互谱估计的统计特性,给出了方位估计概率密度函数的通解形式,在纯噪声和高信噪比两种极端情况下推导了方位估计的数字特征.对低信噪比的方位有偏现象做出了解释,对高信噪比的判别条件给出了定量描述.理论分析与仿真结果一致,从而为湖海实验研究预备了统计知识.

Cross spectrum estimation based on a single vector sensor has turned random process in time domain into random variables in frequency domain. The statistical characteristics of random variables make the physical meaning of the influence imposed on them by isotropic noise field explicit. The first and second moment,and the probability density function(PDF) of cross spectrum estimation are proposed. Collecting the particle velocity information,a single vector sensor may obtain the maximum likelihood DOA(direction of arrival) estimation of the target.Based on the statistical characteristics of cross spectrum estimation,the general solution form of DOA estimation probability density function(PDF)was established,and the digital property is derived in pure noise and high SNR.The phenomenon that the DOA estimation is biased in the low SNR is explained, and the judging conditions for the high SNR are described quantificationally. The theoretical analysis is consistent with the simulation, and all these are providing statistical knowledge for lake and sea trails.