High-speed maneuvering target detection approach based on joint RFT and keystone transform

Increasing the integration time is an effective method to improve small maneuvering target detection performance in radar applications. However, range migration and Doppler spread caused by maneuvering target motion during the integration time make it difficult to improve the coherent accumulation of target's energy and detection performance. In this study, a new method based on Radon Fourier transform (RFT) and keystone transform (KT) for high-speed maneuvering target detection is proposed. The proposed algorithm utilizes second-order KT to correct the range curvature, and the improved dechirping method to compensate for the Doppler spread. RFT is then used to correct the range walk for target coherent detection. The method is capable of correcting the range migration and the time-varied Doppler frequency of the target without knowing its velocity and acceleration. The advantage of the proposed method is that it can increase the coherent integration time and improve detection performance under the condition of Doppler frequency ambiguity. Compared with the second-order RFT algorithm, the computational burden of the proposed method is greatly reduced under the premise that the two methods have similar estimation accuracy of range, velocity and acceleration. Numerical experiments demonstrate the validity of the proposed algorithm.