面向顺飞双站小卫星条带SAR的电扫多普勒中心导引方法  

Electric Scanning Doppler Steering Method for Pursuit Bistatic Small Satellites Strip-map SAR

作　　者：李喆 丁泽刚[1,2] 王岩 孙晗伟 卢晓军[1,4] LI Zhe;DING Ze-gang;WANG Yan;SUN Han-wei;LU Xiao-jun(Radar Research Lab, School of Information and Electronics, Beijing Institute of Technology, Beijing 100081, China;Beijing Key Laboratory of Embedded Real-time Information Processing Technology, Beijing 100081, China;Beijing Institute of Radio Measurement, Beijing 100854, China;China International Engineering Consulting Corporation, Beijing 100048, China)

机构地区：[1]北京理工大学信息与电子学院雷达技术研究所,北京100081 [2]嵌入式实时信息处理技术北京市重点实验室,北京100081 [3]北京无线电测量研究所,北京100854 [4]中国国际工程咨询有限公司,北京100048

出　　处：《信号处理》2018年第11期1313-1320,共8页Journal of Signal Processing

基　　金：北京理工大学青年教师学术启动计划;国家杰出青年科学基金(61625103);高等学校学科创新引智计划(B14010)资助的课题

摘　　要：多普勒导引是保证星载条带SAR正常工作的重要手段。传统星载双站SAR通过分别对主、辅星进行偏航控制实现多普勒导引,该方法对天线安装、波束宽度、基线长度等因素有较高的依赖性。高频段小卫星条带SAR波束较窄,对主、辅星分别进行多普勒导引会引入较大的增益损失;且对于天线指向星下点的小卫星,调整偏航角不再改变信号的多普勒中心,传统方法失效。为解决上述问题,本文提出了一种面向顺飞双站小卫星条带SAR的电扫多普勒中心导引方法。该方法采用电扫描的方式对主、辅星波束指向进行联合调整,并通过多普勒方程的联立保证调整后多普勒中心为零,因此实现了在不降低回波增益的条件下抑制多普勒中心的变化,从而大幅放宽了顺飞双站小卫星SAR受天线安装指向、雷达波段、基线长度的限制。本文使用Ka波段双站小卫星的参数进行了仿真实验,实验结果符合预期,验证了本文方法的有效性。Doppler steering is an important means to ensure the good operation of the spaceborne stripmap SAR. The traditional Doppler steering method of pursuit bistatic SAR is achieved by the separate yaw steering of master and slave satellites, which has a heavy dependence on factors such as antenna installation, beam width and baseline length. The beamwidth of high-band SAR is narrow, and the traditional Doppler steering would introduce a large gain loss; and for small satellites whose antenna points to the nadir, the yaw angle no longer changes the Doppler centroid. In order to solve the problems, this paper proposes a new method of Doppler steering for bistatic small satellite stripmap SAR. This method uses electric scanning to jointly adjust the beam pointing directions of the master and slave satellites, and ensures that the Doppler center is zero by solving the Doppler equation. Then the Doppler centroid variance can be suppressed without reducing the echo gain, and the limitation of the antenna installation orientation, frequency band, and baseline length is eliminated. Besides, computer simulations using the parameters of bistatic Ka-band small satellite SAR are conducted. The results are consistent with expectations, and the effectiveness of the proposed method is verified.

关 键 词：合成孔径雷达 多普勒中心 偏航导引 双站小卫星 电扫描 

分 类 号：TN958[电子电信—信号与信息处理]