天绘二号卫星系统定位精度浅析

A brief analysis of the positioning accuracy for the TH-2 satellite system

天绘二号是我国首个分布式干涉微波测绘卫星系统,本文对其定位精度进行了初探,根据InSAR机理模型分析了影响定位精度的误差源,设计了InSAR数据处理流程,利用地面设计及在轨实测的基线测量精度、地面处理精度指标,对平原、山地地区的卫星定位精度开展了在轨初步测试验证。结果表明,卫星在编队构形700~1050 m基线长度下,在轨获取实测数据处理后平面、高程精度均优于原仿真分析结果,根据地形图测绘规范要求,满足我国平地、山地地区1∶50 000比例尺地形图测绘精度。

The TH-2 satellite system is China’s first microwave surveying satellite system based on distributed interferometric technology. In this paper, the positioning accuracy of the satellite system is studied. According to the InSAR mechanism model, the error sources that affect the positioning accuracy are analyzed, and the InSAR data processing flow is designed. The satellite positioning accuracies in plain and mountain area are tested and verified by using the baseline measurement accuracy and ground processing accuracy of ground design and on-orbit test. The tests show that the plane and elevation accuracy of the satellite system after processing the measured data on orbit is better than that of the original simulation analysis at the baseline length of 700~1050 m in formation configuration, it can satisfy the surveying and mapping precision of 1∶50 000 scale topographic map in plain and mountain area for China.