基于星载照射源的被动SAR系统时频同步误差影响分析

时间和频率同步问题是基于星载照射源的被动SAR系统的关键技术之一。为了研究时、频同步误差对其成像的影响,针对系统工作特性,分析了时、频同步误差的产生机理,建立了时、频同步误差模型,并利用二阶距离模型和RD成像算法,建立了完整的时、频同步误差到成像结果的传递模型,仿真验证了理论分析的准确性。理论推导和仿真计算结果指出了基于星载照射源的被动SAR系统对时间同步和频率同步的精度要求。分析结论对于指导基于星载照射源的被动SAR系统设计及同步方法研究具有重要意义。

Analysis of time and frequency synchronization error for the passive SAR system with spaceborne illuminators

The problem of time and frequency synchronization is a bottleneck technology for the passive SAR system with spaceborne illuminators. In order to analyze the impact of time and frequency synchronization error to passive SAR imaging, the mechanism of time and frequency synchronization error was studied based on the particular operation mode of passive SAR. Then the error model of time and frequency synchronization was established, and the integrated error transfer model from synchronization error to passive SAR imaging was established. In the end, the correctness of the theoretical analysis was validated by simulation experiment. The theoretical analysis and the simulation result show the accuracy requirement of time and frequency synchronization for such a system. The conclusion can be used as principal guidance for passive SAR system design and synchronization method research.