系绳卫星体制高精度INSAR系统设计

High precision INSAR system design for tethered satellite system

针对现有分布式干涉系统难以实现更高比例尺高效率地形测绘的问题,提出了一种基于系绳卫星体制的InSAR系统。首先,结合系绳卫星动力学仿真,给出了系绳干涉系统的几何模型,提出了系绳干涉系统的工作模式,然后研究了系绳卫星SAR载荷的具体工程实现途径,提出了基于系绳电缆解决实现同步和相位同步的方法。首次建立了系绳长度及面内角等参数与模糊高度的关系,对SAR载荷的工作频段、发射峰值功率、天线口径、入射角范围等进行了优化设计。对系绳InSAR系统的关键性能指标进行仿真分析,仿真结果表明该系统可以实现0.5 m测高精度等核心指标。该研究提出了一种1:5000比例尺的高精度测绘SAR系统,相对测高精度比德国的Tandem-X系统提升了4倍,可为我国后续开展高精度星载InSAR工程研制提供参考。

Aiming at the problem that it is difficult for the existing distributed interferometric systems to achieve higher-scale and high-efficiency terrain mapping,this paper proposes an InSAR system based on a tethered satellite system.Firstly,combined with the dynamic simulation of the tethered satellite,the geometric model of the tethered interference system is given,and the working mode of the tethered interference system is proposed.Cables address methods for achieving synchronization and phase synchronization.In this paper,the relationship between the parameters such as tether length and in-plane angle and the blur height is established,and the optimal design of the SAR payload's operating frequency band,transmit peak power,antenna aperture,and incident angle range is carried out.In this paper,the key performance indicators of the tethered InSAR system are simulated and analyzed.The simulation results show that the system can achieve core indicators such as 0.5 m measurement accuracy.This study proposes a high-precision surveying and mapping SAR system with a scale of 1:5000.The relative surveying accuracy is four times higher than that of the German Tandem-X system,which can provide a reference for the subsequent development of high-precision spaceborne InSAR projects in China.