Fast long‐time coherent integration algorithm for detecting manoeuvring targets with high‐order motion parameters based on GKT and ISCPF

Abstract

This study deals with the efficient correction of range migration (RM) and Doppler frequency migration (DFM) for long-time coherent integration in detecting manoeuvring targets with complex motions. A fast long-time coherent integration algorithm based on generalised keystone transform (GKT) and integrating smoothed cubic phase function (ISCPF) is proposed. In particular, GKT and blind velocity fold factor searching is performed to correct the RM. ISCPF is proposed to estimate the acceleration and jerk for correcting the DFM. Consequently, the focus of the target energy is improved. Compared with the algorithm based on generalised Radon Fourier transform, the proposed method achieves a good trade-off between the computational complexity and detection ability because the motion parameters are estimated via locating the peak of a univariate function instead of multi-dimensional searching. Furthermore, the proposed method has better performance compared with several methods based on higher-order ambiguity function and cubic phase function for multiple targets since ISCPF can effectively suppress the cross terms caused by multiple targets. Simulation results are provided to validate the effectiveness of the proposed method.