DEVELOPMENT AND PROGRESS IN GNSS
全球导航卫星系统的进展

Overview of the progress in GNSS, the modernization of GPS, recent situation of GLONASS and the development of GALILEO are presented. Comment on the nuisance effects in GNSS, such as ionospheric and tropospheric propagation delay, multipath mitigation, receiver and satellite antenna phase centre variation, carrier phase ambiguity term are made, and how to reduce these effects is introduced.