While Global Navigation Satellite Systems(GNSS)have been the primary Positioning,Navigation,and Timing(PNT)solution since their advent,new technologies are being sought to address the limitations of GNSS.For the past ...While Global Navigation Satellite Systems(GNSS)have been the primary Positioning,Navigation,and Timing(PNT)solution since their advent,new technologies are being sought to address the limitations of GNSS.For the past few years,the strongest contender to ofer global PNT solutions has been the use of Low Earth Orbit(LEO)satellites,not only to overcome the GNSS limitations but also to improve the positioning accuracy and coverage given the pro-liferation of new,more-demanding applications.The present work aims at shedding light on the LEO theoreti-cally achievable positioning accuracy and interference robustness with respect to GNSS,depending on the choice of the carrier frequency,constellation design,hybridization with GNSS,and available satellite transmission power.The analysis uses a semi-analytical approach with 192,000 Monte Carlo runs,employing an in-house satellite constellation simulator to model 400 users across Europe operating in fve representative outdoor scenarios,and for 480 diferent instances of satellite positions in time.This semi-analytical study provides the necessary insights to derive clear design takeaways depending on the choice of the aforementioned parameters.A moderate Efective Isotropic Radiated Power(EIRP)of 50 dBm is shown to be sufcient for achieving high accuracy outdoors,operating at the C-band in the urban scenarios where GNSS typically struggles.The most cost-efective hybrid LEO plus GNSS solutions come from the combination of 1)‘CentiSpace-like’plus BeiDou,and 2)‘Çelikbilek 1’plus GPS and Galileo,where LEO satellites drive performance in difcult environments while GNSS provides stability in nominal conditions.The fndings suggest using the‘Çelikbilek 1’constellation with a 50 dBm EIRP at a 5 GHz carrier frequency or higher as the most efective system design.展开更多
从导航增强与弹性定位、导航和授时(Positioning,Navigation and Timing,PNT)两个方向,系统阐述基于低轨星座的PNT性能提升能力,包括全球天基监测、全球准实时高精度、可信认证、弹性应急备份等。综合国内外低轨星座发展现状,分析了低...从导航增强与弹性定位、导航和授时(Positioning,Navigation and Timing,PNT)两个方向,系统阐述基于低轨星座的PNT性能提升能力,包括全球天基监测、全球准实时高精度、可信认证、弹性应急备份等。综合国内外低轨星座发展现状,分析了低轨星座实现PNT性能提升的两种实现途径:一是在导航频段播发信号实现性能提升,可与现有各全球卫星导航系统(Global Navigation Satellite System,GNSS)实现良好的兼容与互操作性能;二是利用通信频段播发导航通信(导通)融合信号,实现与现有导航频段信号的弹性应急备份。二者均可实现定位精度及其收敛时间、完好性、安全性等性能提升,但因信号频段和业务类型差异,两者的技术体制、实现能力和代价有所不同。为此,文章从星载接收与处理技术、导航增强和导通融合信号体制设计、同时同频收发干扰抑制技术、弹性终端融合接收处理技术等方面,分析了实现导航增强和弹性PNT服务的关键技术,最后给出了基于低轨星座的PNT性能提升的发展建议。文章的研究成果,有助于进一步探索低轨星座的潜力,促进全球卫星导航系统的发展,并为低轨PNT性能提升技术的研究和应用提供参考。展开更多
基金supported by Tampere University’s Dean’s PhD grant.This work has also been partially supported by the LEDSOL project funded within the LEAP-RE programme by the European Union’s Horizon 2020 Research and Innovation Program under Grant Agreement 963530the Research Council of Finland grant 352364+2 种基金the Spanish Agency of Research(AEI)under grant PID2023-152820OB-I00 funded by MICIU/AEI/10.13039/501100011033ERDF/EU,and grant PDC2023-145858-I00 funded by MICIU/AEI/10.13039/501100011033the European Union NextGenerationEU/PRTR.
文摘While Global Navigation Satellite Systems(GNSS)have been the primary Positioning,Navigation,and Timing(PNT)solution since their advent,new technologies are being sought to address the limitations of GNSS.For the past few years,the strongest contender to ofer global PNT solutions has been the use of Low Earth Orbit(LEO)satellites,not only to overcome the GNSS limitations but also to improve the positioning accuracy and coverage given the pro-liferation of new,more-demanding applications.The present work aims at shedding light on the LEO theoreti-cally achievable positioning accuracy and interference robustness with respect to GNSS,depending on the choice of the carrier frequency,constellation design,hybridization with GNSS,and available satellite transmission power.The analysis uses a semi-analytical approach with 192,000 Monte Carlo runs,employing an in-house satellite constellation simulator to model 400 users across Europe operating in fve representative outdoor scenarios,and for 480 diferent instances of satellite positions in time.This semi-analytical study provides the necessary insights to derive clear design takeaways depending on the choice of the aforementioned parameters.A moderate Efective Isotropic Radiated Power(EIRP)of 50 dBm is shown to be sufcient for achieving high accuracy outdoors,operating at the C-band in the urban scenarios where GNSS typically struggles.The most cost-efective hybrid LEO plus GNSS solutions come from the combination of 1)‘CentiSpace-like’plus BeiDou,and 2)‘Çelikbilek 1’plus GPS and Galileo,where LEO satellites drive performance in difcult environments while GNSS provides stability in nominal conditions.The fndings suggest using the‘Çelikbilek 1’constellation with a 50 dBm EIRP at a 5 GHz carrier frequency or higher as the most efective system design.
