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 directione-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 twenty-four, the estimation error of the spatial domain parameters is less than one degree 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.