弹载合成孔径雷达自适应重频分析与设计

弹载合成孔径雷达(Synthetic Aperture Radar，SAR)的目标距离、视线角由于高速逼近目标而快速变化，这导致传统的固定脉冲重复频率(Pulse Repetition Frequency，PRF)(简称重频)波形难以兼顾弹载SAR雷达在成像各方面的约束条件，故需要根据当前弹体运动和弹目关系变化情况实时计算重频。详细分析了影响重频选择的各项因素，包括避免距离模糊、方位模糊、高度杂波、发射遮挡影响及SAR成像分辨率、系统相参性要求等影响因素，并设计了自适应重频计算的工作流程。某SAR雷达系统实验表明，该设计能够在实际飞行弹道条件下根据实际弹目关系自适应调整脉冲重复频率，从而更好地实现SAR雷达系统的工作性能，有效解决了固定重频波形不能适应弹载SAR工作条件的难题。

Self-adaption PRF Analysis and Design of Missile-borne SAR

The target distance and aspect angle of the missile-borne synthetic aperture radar(SAR) change rapidly due to high-speed approaching the target, it is difficult for the traditional fixed pulse repetition frequency(PRF) waveform to take all the constraints into account in missile-borne SAR imaging. Therefore, it is necessary to calculate the PRF in real-time according to the current missile motion and the change of missile-target relationship. In this paper, the factors that affect the choice of PRF are analyzed in detail, including the avoidance of distance ambiguity, azimuth ambiguity, height clutter and emission occlusion, SAR imaging resolution, system coherence requirements and other influencing factors. Then the work flow of adaptive PRF calculation is designed. A SAR system experiment shows that the design in this paper adaptively adjusts the PRF according to the actual missile-target relationship under the actual flight ballistic conditions to better meet the SAR radar system performance and effectively solves the difficulty of fixed PRF waveform could not adapt to missile-borne SAR working conditions.