导航政策是GNSS的重要组成部分上世纪70年代中期,美国提出了GpS(全球定位系统)的概念,并且逐步付诸实施,至今已经接近40年。从GPS开始投入完全服务的1995年至今,也有20年了。与GPS同期建设的原苏联的格洛纳斯(GLONASS),以及1990年代和本世纪初进行试验与建设的欧洲伽利略和中国的北斗系统,瞄准的目标全是建 Navigation policy is an important part of GNSS In the mid-1970s, the United States put forward the concept of GpS (Global Positioning System) and put it into effect gradually. It has been nearly 40 years. It has been 20 years since 1995 when GPS was put into full service. The former Soviet Union’s GLONASS, built in the same period as the GPS, and the European Galileo and China’s Beidou system, which were experimented and built in the 1990s and early 2000s, are all aimed at building