The DOA Estimation Method for Low-Altitude Targets under the Background of Impulse Noise

Abstract

Due to the discontinuity of ocean waves and mountains, there are often multipath propagation effects and obvious pulse characteristics in low-altitude detection. If the conventional direction of arrival (DOA) estimation method is directly used for direction finding, it will lead to a large error. In view of serious misalignment in the DOA estimation of multipath signals under the background of impulse noise, a DOA estimation method based on spatial difference and a modified projection subspace algorithm is proposed in this paper. Firstly, the covariance matrix of the received data vector is used for spatial difference to eliminate the multipath effects of low-altitude targets. Secondly, the modified projection matrix is constructed using the signal source estimated with the least squares criterion and then used for modifying the covariance matrix, thus eliminating the cross-covariance matrices that affect the estimation accuracy. Finally, the modified covariance matrix is used for the DOA estimation of targets. Simulations show that the proposed algorithm achieves a higher accuracy in the DOA estimation of low-altitude targets than conventional algorithms under two common impulse noise models, without requiring prior knowledge of impulse noise.

Angle of Arrival Estimator Utilizing the Minimum Number of Omnidirectional Microphones

“…For estimating the AOA of coherent signals in the ULA, MUSIC was modified by reconstructing a noise subspace [18]. In [19], a DOA estimation method based on spatial difference and a modified projection subspace algorithm was proposed for handling serious misalignment in the AOA estimation of multi-path signals under the background of impulse noise. The reference [20] introduced a modified MUSIC estimator to compute the AOA of multiple radio frequency signals, considering an antenna array with an imperfectly calibrated array response.…”

Kernel Function-Based Ambiguity Function and Its Application on DOA Estimation in Impulsive Noise

“…Direction of arrival (DOA) estimation is a key field of array signal processing and has broad applications in radar, sonar, source localization, wireless communications, and other areas [1,2]. After decades of development, a relatively complete DOA estimation theory has been established.…”