Sparse recovery(SR)space-time adaptive processing(STAP)requires few training samples,and it performs well in the inhomogeneous clutter environments.However,the clutter ridges in the bistatic configuration do not fall on the uniform grid points,which causes off-grid problem and seriously affect the performance of the SR-STAP method.To overcome off-grid effect of bistatic airborne radar,this paper proposes a SR-STAP method that uses the prior information of clutter ridges to divide non-uniform grids.The proposed method firstly obtains the clutter space-time trajectory of the cell to be tested by the navigation system or parameter estimation method,and then determines the initial normalized Doppler frequency set from the space-time trajectory and the uniformly divided spatial frequency.Then,the proposed method updates the normalized Doppler frequency set according to the adjustable parameters.Finally,the proposed method constructs the corresponding non-uniform dictionary.The proposed method can be applied to any bistatic configuration.The simulation results show that the SR-STAP method with non-uniform dictionary has better clutter suppression performance than the traditional uniform dictionary,and it can perform robustly under non-ideal conditions.
维普
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