空间目标双基地ISAR速度补偿研究

摘要

针对空间高速运动目标的双基地逆合成孔径雷达(ISAR)成像问题,提出了基于相位精确补偿的速度补偿算法.首先,根据双基地雷达几何关系推导了高速运动目标到收发双站的时间延迟,建立了双基地ISAR回波模型,分析了高速运动对一维距离像性能的影响;然后,通过构造相位补偿项完成了对回波数据的速度补偿,并提出了基于最小熵的速度估计算法;最后,研究分析了速度误差对脉冲压缩及成像的影响.仿真结果表明,速度补偿算法能够消除速度引起的距离像主瓣展宽和位置畸变,得到高质量的ISAR二维像,并验证了速度估计算法的有效性.该方法为RD全相参成像和BP算法等对目标位置精度要求很高的成像算法的实施提供了速度补偿依据.%Aiming at the problem of the bistatic inverse synthetic aperture radar (ISAR)imaging of high speed moving target in space,a speed compensation algorithm is proposed in this paper. Firstly,the delay time of target to transmitting and receiving station is derived according to the geometry relationship of bistatic radar,and the echo model of bistatic ISAR is built.The effect of high speed on range profile is analyzed.Then,the compensation phase item is created and the speed compensation is made.The speed estimate algorithm is proposed based on minimum entropy.Finally,the effect of speed error on pulse compression and imaging is analyzed.The simulation result shows that the compensation algorithm can eliminate mainlobe extension and location distortion of one-dimensional range profile.The algorithm provides the compensation basis for the implementation of coherent range doppler (RD ) imaging method and back projection (BP)algorithm which has high demand to target position accuracy.