中国空间科学技术

中国空间科学技术 ›› 2025, Vol. 45 ›› Issue (3): 100-109.doi: 10.16708/j.cnki.1000.758X.2025.0042

• 论文 • 上一篇    下一篇

基于反射面天线的Geo-SAR卫星凝视模式姿控方法

赵秉吉1 ，贺玮1,2，* ，张庆君1 ，索志勇3 ，遆晶晶3   

  1. 1.中国空间技术研究院 遥感卫星总体部，北京100094
    2.国防科技大学 电子科学学院，长沙410073
    3.西安电子科技大学 雷达信号处理全国重点实验室，西安710071
  • 收稿日期:2024-08-13 修回日期:2024-12-24 录用日期:2024-12-28 发布日期:2025-05-15 出版日期:2025-06-01

Staring mode attitude control of Geo-SAR satellite with reflector antenna

ZHAO Bingji1, HE Wei1,2,*, ZHANG Qingjun1, SUO Zhiyong3, TI Jingjing3   

  1. 1.Institute of Remote Sensing Satellite, CAST, Beijing 100094, China
    2.College of Electronic Science and Technology, National University of Defense Technology, Changsha 410073, China
    3.National Key Laboratory of Radar Signal Processing, Xidian University, Xi’an 710071, China
  • Received:2024-08-13 Revision received:2024-12-24 Accepted:2024-12-28 Online:2025-05-15 Published:2025-06-01

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摘要： 针对基于反射面天线的Geo-SAR(Geosynchronous Synthetic Aperture Radar)凝视成像模式下的卫星姿态控制方法进行研究，解决卫星快速机动问题，提升时效性。首先，阐述了Geo-SAR卫星凝视模式的成像模型和多普勒历程特性，并与低轨SAR卫星的差异进行对比。Geo-SAR卫星有大偏航角的特点，利用传统二维偏航导引方法，实现正侧视推扫成像，最大姿态控制角度可达约±76°，姿控时间过长，响应能力差，无法发挥Geo-SAR快速响应的优势。为了解决该问题，提出一种定点凝视的二维俯仰滚动姿态控制角度算法，可实现卫星全轨对任意地面场景持续定点凝视。该方法最大姿态控制角度可减小至约±7.2°，姿态调整时间缩短了至少一个数量级，极大提升了卫星的好用易用性。最后，阐述了针对Geo-SAR凝视成像模式的快速BP(Back Projection)成像算法，并完成了25m×25m分辨率点目标成像仿真，聚焦结果良好，成像指标达到理论值，验证了所提出的姿控方法的正确性。结论表明提出的方法可以将Geo-SAR卫星的姿态机动时间缩短至少一个量级，提升卫星响应能力，可为后续Geo-SAR卫星姿控方案设计提供参考。

关键词: 地球同步轨道SAR, 反射面天线, 二维俯仰滚动姿态控制, 凝视模式, 姿控时间

Abstract: To improve the repeating cycle of Geo-SAR through prompt attitude control method, the staring mode attitude control property and system parameters’ performance of Geo-SAR with reflector antenna are presented. The approach illuminated in this paper aims to shorten the attitude control time, and to improve the revisiting effect. Firstly, Geo-SAR staring mode model and Doppler history are illustrated and compared with those of low earth orbital SAR (Leo-SAR). Its maximum yaw angle to be compensated for broadside imaging is about ±76° when traditional two-dimensional yaw steering (2D-YS) method is used. A new twodimensional pitch and roll squint control (2D-PRSC) algorithm is advanced, which can make satellite continuously stare at any scene in the whole orbital period. The maximum attitude control angle is about ±7.2°, and the capability of satellite is obviously improved. Finally, Geo-SAR fast BP imaging algorithm is illustrated in this paper. The point target with 25m×25m resolution is simulated, the imaging results are good and meet the theory parameters. The simulation results show that the new method in this paper is correct. As the reference scheme for attitude system design, the method can shorten the Geo-SAR attitude control time to about 1/10 of the original value.

Key words: Geo-SAR, reflector antenna, 2D pitch and roll attitude control, staring mode, attitude control time