Coherent Accumulation Method for Short-Range High-Velocity Target Based on PRF Agile Radar

In pulse repetition frequency (PRF) agile radar systems, when the target has high velocity or the coherent processing time is too long, the random PRF variations cause the echo pulse to appear to shift across the range unit during coherent accumulation, making it impossible to obtain accurate velocity and range information through coherent accumulation. To address this issue, this paper proposes the utilization of the Keystone transform to correct the range migration caused by random variations in the PRF. Additionally, the non-uniform fast Fourier transform (NUFFT) is applied along the slow-time dimension, enabling accurate acquisition of target velocity and range information through coherent accumulation. Furthermore, in a multi-target scenario, the proposed method enables accurate detection of each target. Simulation test results demonstrate the effectiveness of the proposed method in correcting range migration during coherent accumulation in PRF agile radar, thereby accurately obtaining velocity and range information for each target in the multi-target scenario. Moreover, the computational complexity is reduced by utilizing the Chirp-z algorithm, which requires less computational resources, for implementing the Keystone transform.