分布式SAR时间同步误差的影响分析与试验验证  

Effect Analysis of Time Synchronization Error of Distributed SAR and Experiment Validation

作　　者：何志华[1] 何峰[1] 张永胜[1] 梁甸农[1] 

机构地区：[1]国防科学技术大学电子科学与工程学院,长沙410073

出　　处：《宇航学报》2011年第6期1373-1378,共6页Journal of Astronautics

摘　　要：时间同步是空间同步和相位同步的工作前提,是实现星载分布式SAR干涉测量的核心问题。基于多项式时间同步误差模型,给出了含时间同步误差的数字回波信号仿真模型。采用理论分析与全数字仿真试验相结合的方式分析了时间同步误差对干涉测绘带损失、双站SAR成像以及干涉测高精度的影响。基于包含SAR载荷和时间同步样机等实物在内的半实物仿真系统,提出了采用不同设备连接方案的误差隔离和溯源试验评估方法,通过试验结果对比分析得到时间同步误差对干涉测高的准确影响结果。最后综合得到对时间同步分系统的输入输出指标要求。本文工作对时间同步的工程实现提供有力支撑。Time synchronization is an important prerequisite for the beam and the phase synchronization in the spaceborne distributed SAR.It is a key problem for the interferometric measurement.Based on a polynomial time synchronization error model,a raw signal model containing time synchronization error is introduced in this paper.Then,the effect of the time synchronization error on the interferometric swath loss,the bistatic SAR imaging,and the interferometric height measurement accuracy is analyzed by using both the theoretical analysis and the computer-based simulation method.Based on the hardware-in-loop simulation system with the SAR payloads and the time synchronization prototype in the simulation loop,an error isolated evaluation method by different hardware configuration is proposed.Accurate effect of the time synchronization error on the interferometric height measurement accuracy is obtained by analyzing the simulation results.At last,the input and output specification requirements of the time synchronization subsystem are given.The work of this paper offers powerful support for the engineering realization of the time synchronization subsystem.

关 键 词：分布式SAR 时间同步误差 半实物仿真试验 干涉测高误差 

分 类 号：TN957[电子电信—信号与信息处理]