中文摘要：

广域实时精密定位技术为移动互联网、物联网的发展提供了重要的时空基准.主要介绍广域精密定位的增强电文服务系统的相关框架与核心算法：1）设计了时空自适应的低冗余增强电文编码和传输协议,对卫星轨道钟差改正数采用有效位截取的压缩算法,对电离层改正数据采用时空自适应的格网分层离散化方法进行播发;2）设计了基于虚拟化弹性调度的多级数据播发机制,通过资源的动态分配和弹性扩展算法提高系统可靠性;3）通过一系列城市环境下车联网精准定位实验,验证系统的服务质量,分析了网络信号、地理环境、通视条件等众多因素对精密定位的影响.

英文摘要：

Wide area real-time positioning technology provides space-time reference for mobile Internet and Internet of things. This pa- per introduces the related framework and core algorithm of the enhanced message service system in wide area real-time positioning ： 1 ） We designed a low redundancy and temporal/spatial adaptive enhance message encoding and transmission protocol. It compresses and transmits precise ephemeris,satellite clock correction data based on the interception significant bits and using hierarchical grid discreti- zation methods to broadcast ionosphere corrections in a spatial and temporal adaptive way. 2 ） We also designed a multi-level data broadcast mechanism based on a virtualized flexibility scheduling,improving the system reliability through the dynamic recourse allo- cation and expansion algorithm. 3） We verified the quality of the service system through a series of precise positioning experiment in urban environment. We analyzed the effect of network signal, geographical environment and visibility condition on precise positioning service.