摘要
GNSS星基导航系统易受敌方干扰,且易受遮挡,使其在军事应用中存在较大的风险和局限性。地基长波授时系统具有发射功率大、抗电磁干扰强等优势,且长波发射台可以当作GNSS系统的伪卫星来使用。因此,长波授时系统和GNSS系统进行组合定位取长补短,可以大大提高导航系统的可用性,降低在军事应用中的风险。首先从性能上分析两个系统进行组合定位的可行性;再从理论上对双系统组合定位方法进行研究,并提出校正—融合的组合定位算法用以修正长波授时系统的系统误差,进一步优化组合定位性能;然后,以西安为例分析长波授时系统和北斗系统组合定位对几何精度因子的改善情况;最后,基于实测数据研究长波授时系统和北斗系统组合定位性能。研究结果表明,地基长波授时系统与北斗组合定位,能大大改善几何精度因子,对多遮挡环境下的改善尤为明显。采用笔者提出的组合定位算法,基于北斗伪码接收机可以达到数十米量级的定位精度,相比北斗单系统导航组合定位精度有一定恶化,但是如果后期对长波数据增加平滑滤波处理,组合定位性能会进一步提升。
GNSS can be easily interfered and blocked-off because of its technique characteristics, thus, it isof limitation and will bring risk if use only GNSS system in national military applications. The long wave timeservice system such as BPL is a kind of terrestrial radio transmitting system, which adopts Loran-C （Long RangeNavigation System） signal format and has the advantages of great transmitting signal power and strong ability ofanti-electromagnetic interference. So far, the synchronization of LF time and UTC time has been completedbased on common view link, so the LF time transmitting station can be considered as a pseudo-satellite of GNSS.Thus, LF time service system and GNSS can be integrated to improve the usability of navigation systems andreduce the risk of military application. Firstly, the accuracy of long wave timing is studied and compared withthat of BDS, and the feasibility of integrated navigation is analyzed based on the performance. Then, the theoryand method of integrated positioning is introduced, meanwhile the integrated positioning algorithm based oncalibration-fusion is presented to correct the systematic error of long wave data and achieve further improvementof the performance of integrated positioning. Furthermore, Xi’an is taken as an example to analyze the effect ofintegrated positioning on geometric dilution of precision （GDOP）. Finally, the performance of integratedpositioning is researched based on the data collected from the receivers of two systems, and the result ofintegrated positioning is compared with that of single BDS. The research results show that integrated positioningof LF time service system and BDS can improve GDOP greatly, and the effect is more obvious in blocked-offarea; the positioning accuracy of tens of meters can be achieved based on pseudo-code receiver if the integratedpositioning algorithm is used, which is slightly worse than single BDS positioning.
出处
《时间频率学报》
CSCD
2017年第3期161-177,共17页
Journal of Time and Frequency
基金
中国科学院"西部之光"人才培养计划西部青年学者A类资助项目(XAB2016A05)
关键词
GNSS
长波授时
组合定位
DOP
定位精度
GNSS
LF time service
integrated positioning
DOP
positioning accuracy
