DOA Estimation of Two-Dimensional Coherently Distributed Sources Based on Spatial Smoothing of Uniform Rectangular Arrays

Tao Wu,Yijie Huang,Yiwen Li,Chaoqi Fu,Qingyue Gu,Xiaofeng Zhang

doi:10.1155/2019/4816183

Abstract

Aiming at the direction-of-arrival (DOA) estimation of two-dimensional (2D) coherently distributed (CD) sources which are coherent with each other, we explore the propagator method based on spatial smoothing of a uniform rectangular array (URA). The rotational invariance relationships with respect to the nominal azimuth and nominal elevation are obtained under the small angular spreads assumption. A propagator operator is constructed through spatial smoothing of sample covariance matrices firstly. Then, combination of propagator and identical matrix is divided according to rotational operators, and the nominal angles can be obtained through eigendecomposition lastly. Realizing angle matching automatically, the proposed method can estimate multiple DOAs of 2D coherent CD sources without spectral peak searching and prior knowledge of deterministic angular signal distribution function. Simulations are conducted to verify the effectiveness of the proposed method.

Highlights

In the field of array signal processing, traditional DOA estimation is based on point source models
All simulation experiments are based on array configuration as shown in Figure 1. e distance of adjacent sensor d is set at λ/2
We have considered the problem of estimation of 2D coherent coherently distributed (CD) sources utilizing uniform rectangular array (URA). e rotation invariance relationships within and between subarrays have been deduced under the small angular spreads assumption

Summary

Introduction

In the field of array signal processing, traditional DOA estimation is based on point source models. In the real surroundings of radar and sonar systems, because of multipath propagation between receive arrays and targets, especially when the distances of targets and receive arrays are short, the spatial scattering of targets cannot be ignored, and the assumed condition of point source models is no longer valid. In such a condition, DOA estimation based on distributed source models has presented better accuracy [1]. According to coherence of scatterers, distributed sources can be classified as coherently and incoherently distributed sources [1]. Distributed (ID) sources are defined as scatterers within a source which are uncorrelated

Methods

Results

Conclusion