随机线性调频步进雷达波形设计及成像算法研究

Waveform Design and Imaging Algorithm Research of Random Frequency Stepped Chirp Signal ISAR

线性调频步进信号能在不增加系统瞬时带宽的情况下用数字信号处理的方法获得高的距离像分辨率,是一种高效的雷达信号形式。针对传统的线性调频步进信号抗干扰能力较差的问题,该文提出一种可以随机发射线性调频步进信号子脉冲的波形设计方法,结合压缩感知理论,运用较少的子脉冲实现了对运动目标1维距离像的重构和高分辨的2维成像。在此基础上,进一步分析了目标运动对随机线性调频步进信号雷达成像的影响,设计了包含测速脉冲的随机线性调频步进信号,并提出了基于时频分析、Radon变换和二值数学形态学相结合的运动速度估计及补偿方法。仿真实验验证了随机线性调频步进信号逆合成孔径雷达的性能及该文方法的有效性。

Frequency-stepped chirp signal is an effective radar signal which can utilize the digital signal processing to obtain high range resolution with relatively narrow instantaneous bandwidth.Because the anti-jamming ability of frequency-stepped chirp signal radar is not enough,the random frequency-stepped chirp signal is designed,and a random frequency-stepped chirp signal ISAR imaging algorithm based on compress sensing theory is proposed.The range profile and high resolution 2-D ISAR image can be obtained with fewer subpulses.Then,the target velocity＇s influence on frequency-stepped chirp signal radar imaging is analyzed,the random frequency-stepped chirp signal which contains velocity measuring subpulses is designed,and the velocity estimate and compensation method which is combined with time-frequency analysis,Radon transform and binary mathematical morphology is proposed.The simulation verifies the capability of random frequency-stepped chirp signal ISAR and effectiveness of the imaging algorithm proposed in this paper.