Key technologies of TH-2 satellite system

doi:10.11947/j.AGCS.2022.20210567

Abstract

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

CLC Number:

P236

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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