Research on DOA technique of non-ideal array based on rotating projectile

Objective This paper proposes an online calibration direction-of-arrival (DOA) estimation algorithm to solve the problem of error interference by strong clutter in the flight of a rotating missile direction-finding system.

Method Using the prior condition of the known array-rotation angles, the maximum likelihood criterion-based method is used to estimate the conformal array errors and spatial-polarization parameters of the signal.

Results The simulation experiment results show that the proposed algorithm can achieve online error calibration and signal parameter estimation for arrays with angle-dependent amplitude-phase inconsistency errors. Moreover, the estimation performance of the algorithm is related to the rotation times of the array platform and signal-noise ratio (SNR) ratio. When the number of rotations exceeds 24, the estimation error of the spatial domain parameters is less than 1° under the condition of low SNR = 10 dB.

Conclusion The proposed algorithm uses the idea of fractal dimension alternating processing to solve the multi-parameter estimation problem, enabling it to ensure the convergence of parameters and greatly reduce computational complexity.