全球导航星座星间链路技术发展建议

Development Recommendation of Inter-satellites Links in GNSS

美国全球定位系统(GPS)的Block IIR和Block IIF系列导航卫星安装了UHF频段的星间链路收发设备,未来的GPS Ⅲ系列导航卫星将用Ka频段星间链路替代UHF频段星间链路,提高星间数据通信容量,增强抗干扰能力;俄罗斯全球导航卫星系统(GLONASS)的新一代GLONASS-K系列导航卫星开始安装S频段星间链路收发设备;欧洲的伽利略(Galileo)卫星导航系统也在规划全球导航星座的星间链路体系;我国北斗(Compass)卫星导航系统正处在由区域覆盖向全球覆盖的过渡阶段,全球星座的星间链路正处在多种系统体制的抉择中。文章在对国外各种星间链路研究的基础上,从导航星座星间链路需求和特点出发,提出建议:1)建设高频段星间链路;2)加强星间天线与卫星总体的联合设计;3)星间网络协议要具有灵活性;4)尽可能保持每颗卫星的星间链路设备状态一致。文章考虑了现有国内技术储备和国外未来技术发展方向,提出的观点可以作为我国全球卫星导航系统对星间链路选择的参考,对我国Compass系统建设技术先进的星间链路有一定的指导意义。

Global Positioning System （GPS） block IIR and IIF satellites have fixed crosslink transponder with UHF band,and future GPS block Ⅲ satellites will have directional Ka-band inter-satellites links （ISLs） to replace UHF-band ISLs,which can increase communications capacity and anti-jamming capability. Global navigation satellite system （GLONASS） of Russia has armed new generation satellites （GLONASS-K） with S-band crosslinks. Plans of ISLs for Galileo satellite navigation systems of Europe are in preparation. Chinese Compass satellite navigation system is in the interim from China region to the worldwide,and the architecture of ISLs of Compass is in a dilemma. Based on the research of many types of ISLs aboard and issued from requirements and characteristics of ISLs in Global Navigation Satellite Systems（GNSS）,this paper recommends that directional ISLs with higher frequency band should be adopted in GNSS. Other pieces of advice are integrated design between crosslink antennas and spacecraft,flexible network protocol between satellites,and consistency of ISL products in navigation constellation. The development recommendation in this paper,as a selection of GNSS ISL system,can guide researchers and engineers to construction of advanced ISLs for Compass,which takes into consideration pre-sent technology level and future technique trend of ISLs.