Zhang Chunxi, Li Xianmu, Gao Shuang, Lin Tie, Wang Lu
School of Instrument Science and Opto-electronics Engineering, Beihang University, Beijing 100191, China.
Sensors (Basel). 2017 Apr 28;17(5):980. doi: 10.3390/s17050980.
Under the high dynamic conditions, Global Navigation Satellite System (GNSS) signals produce great Doppler frequency shifts, which hinders the fast acquisition of signals. Inertial Navigation System (INS)-aided acquisition can improve the acquisition performance, whereas the accuracy of Doppler shift and code phase estimation are mainly determined by the INS precision. The relation between the INS accuracy and Doppler shift estimation error has been derived, while the relation between the INS accuracy and code phase estimation error has not been deduced. In this paper, in order to theoretically analyze the effects of INS errors on the performance of Doppler shift and code phase estimations, the connections between them are re-deduced. Moreover, the curves of the corresponding relations are given for the first time. Then, in order to have a better verification of the INS-aided acquisition, a high dynamic scenario is designed. Furthermore, by using the deduced mathematical relation, the effects of different grade INS on the GNSS (including Global Positioning System (GPS) and BeiDou Navigation Satellite System (BDS)) signal acquisition are analyzed. Experimental results demonstrate that the INS-aided acquisition can reduce the search range of local frequency and code phase, and achieve fast acquisition. According to the experimental results, a suitable INS can be chosen for the deeply coupled integration.
在高动态条件下，全球导航卫星系统（GNSS）信号会产生很大的多普勒频移，这阻碍了信号的快速捕获。惯性导航系统（INS）辅助捕获可以提高捕获性能，而多普勒频移和码相位估计的精度主要由INS精度决定。已经推导了INS精度与多普勒频移估计误差之间的关系，而INS精度与码相位估计误差之间的关系尚未推导出来。本文为了从理论上分析INS误差对多普勒频移和码相位估计性能的影响，重新推导了它们之间的联系。此外，首次给出了相应关系的曲线。然后，为了更好地验证INS辅助捕获，设计了一个高动态场景。此外，利用推导的数学关系，分析了不同等级的INS对GNSS（包括全球定位系统（GPS）和北斗导航卫星系统（BDS））信号捕获的影响。实验结果表明，INS辅助捕获可以减小本地频率和码相位的搜索范围，实现快速捕获。根据实验结果，可以选择合适的INS进行深度耦合集成。
