GNSS Imaging: a Case Study of Tree Detection Based on BeiDou GEO Satellites
GNSS Imaging: a Case Study of Tree Detection Based on BeiDou GEO Satellites
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DOI：
10.2528/pierc18032504
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发表时间：
2018
影响因子：
--
通讯作者：
Songhua Yan;Hui Zhou;J. Gong
中科院分区：
文献类型：
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作者：
Songhua Yan;Hui Zhou;J. Gong
传统导航卫星的弯曲轨道限制了其在双基地雷达成像系统中的性能。为解决这一问题，提出了一种基于北斗地球同步轨道(GEO)卫星的全球导航卫星系统(GNSS)成像系统，取代了常用的倾斜地球同步轨道(IGSO)/中地球轨道(MEO)卫星。GEO卫星最突出的特点是它们仍然是相对于地球的。这项工作包括三个部分。首先，为了简化成像系统的几何拓扑结构，提出了合理的并行假设，并推导了相应的路径延迟公式。其次，提出了基于多颗GEO卫星的成像原理，并给出了仿真结果。第三，整个信号处理采用多相关器，以提高距离分辨率。描述了两个针对树木的成像实验，并在武汉大学进行了成像实验，以验证成像系统。第一个实验的目标是孤立的树木，第二个实验的重点是沿路的小树林。得出结论：成像结果与成像区域高度一致，验证了该方法的可行性，证实了GNSS成像系统在森林监测中的应用潜力。
Curved trajectories of traditional navigation satellites limit their performance in bistatic radar imaging system. Instead of using common Inclined Geosynchronous Orbit (IGSO)/Medium Earth Orbit (MEO) satellites in motion, a new global navigation satellite system (GNSS) imaging system based on Beidou geo synchronous orbit (GEO) satellites is presented to deal with this problem. The most prominent feature of GEO satellites is that they are still relative to the earth. This work includes three parts. First, a reasonable parallel assumption is provided to simplify the geometric topology of the imaging system, and the relevant path delay formula is deduced. Second, the principle of imaging based on multiple GEO satellites is proposed, and the simulation result is presented. Third, the entire signal processing, which uses a multi-correlator, is designed to improve the range resolution. Two imaging experiments targeting at the trees are described and conducted in Wuhan University to verify the imaging system. The first experiment is targeted at isolated trees, and the second experiment is focused on groves along the road. Conclusion can be obtained: the imaging result is highly consistent with the imaging area, which validates the feasibility of the method and confirms the potential use of GNSS imaging system in forest monitoring.