An Efficient Coherent Integration Method for High-Speed Maneuvering Target with Nonlinear Motion

Abstract

Long-time coherent integration (LTCI) can effectively improve the target detection and motion parameters estimation ability of radar for high-speed maneuvering target. However, the range migration (RM) and Doppler frequency migration (DFM) effects caused by maneuvering target will defocus the signal energy, which may seriously degrade the performance of detection and estimation. In this paper, an efficient coherent integration approach based on second-order keystone transform (SKT), modified axis rotation (MAR) and linear canonical transform (LCT), i.e., SKT-MAR-LCT, is proposed to accomplish target detection and motion parameters estimation. The proposed algorithm first uses SKT to eliminate the range curvature, and then uses the geometric relationship between the radial velocity and the slope angle of pulse compression signal to correct the linear range walk through MAR. Finally, after the target energy is concentrated in one range bin, we extract the signal and complete the energy integration via LCT. In comparison with the existing representative coherent detection methods, SKT-MAR-LCT can achieve a better balance between target detection performance and computational complexity. Mathematical analysis and simulations demonstrate the effectiveness of SKT-MAR-LCT.