天绘二号卫星关键技术

doi:10.11947/j.AGCS.2022.20210567

摘要/Abstract

摘要： 天绘二号卫星是我国第1个InSAR测绘卫星,也是第1个近距离编队卫星系统,它由两颗合成孔径雷达卫星组成,采用异轨道面卫星编队、一发双收雷达收发模式的技术体制,利用卫星编队形成干涉所需的基线,可以快速测制全球1∶5万比例尺数字表面模型和雷达正射影像。本文在介绍了InSAR测量原理基础上,阐述了天绘二号卫星技术体制;在该体制下,为了确保系统性能及产品精度,需要解决卫星编队、双星协同工作、高精度内定标、基线确定、高精度基线测量、高精度基线定标、高保相成像及利用双频解算干涉相位绝对模糊数等关键技术,文中对这些关键技术进行了分析研究,并提出了解决途径。在天绘二号卫星研制期间,利用仿真数据和半实物仿真试验对关键技术解决途径的可行性进行了验证;卫星发射上天后,在轨测试结果表明,系统运行状态良好,主要性能指标优于设计指标,由此进一步验证了关键技术解决途径的可行性和方法的正确性。

关键词: 天绘二号, 干涉合成孔径雷达, 卫星编队, 时间同步, 空间同步, 相位同步, 基线测量, 基线定标

Abstract: The TH-2 satellite system is the first microwave surveying satellite system based on interferometric synthetic aperture radar (InSAR) technology and the first short-range formation satellite system in China. It is composed of two equal satellites, and the satellites formation in different orbits and the bistatic radar transceiver mode are adopted. By using satellite formations to form the baseline needed for interference, it can measure the global digital surface models by scale of 1∶50000 in a short time and acquire radar orthophotos at the same time. This paper gives a detailed introduction of the InSAR measurement principle and the technical system of TH-2 is also expounded carefully. To ensure the performance of system and the accuracy of product, several key techniques such as satellite formation, cooperative mode of two satellites, high-precision internal calibration, baseline determination, high-precision baseline measurement, high-precision baseline calibration, imaging of high phase fidelity and absolute ambiguity number calculation using dual-frequency need to be solved. These key technologies are analyzed in this paper, and the solutions are proposed. During the development of the TH-2 satellite system, simulation data and semi-physical simulation test were used to verify the feasibility of the main key technology solutions. After the satellites were launched, the on orbit test showed that the system was operating in good condition and the main performance indicators were better than the designed indicators, which further verified the feasibility of the key technology solutions and the correctness of these methods.

Key words: TH-2, InSAR, satellite formation, time synchronization, space synchronization, phase synchronization, baseline measurement, baseline calibration

中图分类号:

P236

楼良盛, 刘志铭, 张昊, 钱方明, 张笑微. 天绘二号卫星关键技术[J]. 测绘学报, 2022, 51(12): 2403-2416.

LOU Liangsheng, LIU Zhiming, ZHANG Hao, QIAN Fangming, ZHANG Xiaowei. Key technologies of TH-2 satellite system[J]. Acta Geodaetica et Cartographica Sinica, 2022, 51(12): 2403-2416.

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