Array self-calibration method based on covariance matrix separation of error-free array

Because the array amplitude and phase errors will degrade the performance of the high-resolution direction of arrival (DOA) estimation method, an array self-calibration method based on the covariance matrix separation of the error-free array is proposed. This method applies the covariance matrix reconstruction method to obtain the covariance matrix of an approximate error-free array, which weakens the array error in the covariance matrix. Then, the eigenstructure method is used to solve the amplitude and phase errors. The above reconstruction method and eigenstructure method are iterated to separate the error-free array covariance matrix and the amplitude-phase error matrix from the covariance matrix of the uncalibrated array. Simulation results show that the proposed method can accurately estimate the array errors, and using the reconstructed covariance matrix for DOA estimation can improve the resolution and estimation accuracy. The lake experiment results show that the sound source and interference target with adjacent azimuth angles can be distinguished after calibrating the array using the proposed method.