中文摘要：

2003年10月，加拿大自然资源部大地测量司开发了一套在线定位服务系统CSRS—PPP。GPS用户可以通过网络向该系统提交单点GPS观测文件，之后就能得到高精度的单点定位结果。本文首先对PPP技术的发展历程作了回顾，并详细介绍了CSRS—PPP系统以及IGS精密产品，最后分析讨论了该系统的静态和动态定位精度，取得了一些有益的结论。相对于传统的使用广播星历的单点定位方法，CSRS—PPP可以使单点定位精度提高2～100倍，其单点定位结果与相位差分GPS定位精度相当，并且不需要基准站同步观测。研究结果对控制点的建立、GPS基准站的建立和线路测量等工作有一定的实际价值。

英文摘要：

In October 2003, the Geodetic Survey Division of Natural Resources Canada developed an on - line service system CSRS - PPP（ CSRS - Precise Point Positioning） for GPS users that allows GPS users achieve accurate point positioning by submitting GPS observations from a single receiver over the Internet. In this paper, we first reviewed the progress of PPP technology. Then, CSRS - PPP system and precise products from IGS was introduced. At last, we discussed the positioning precision of the system on static or kinematic mode by examples. Relative to the traditional point positioning using broadcasting ephemeris, the resultant precision of PPP improved about 2 - 100 times, which is comparable to phasedifferential GPS without the need to access or process data collected simultaneously at a base station. The research outcomes have some practical value for establishment of control points and GPS base stations, and other related jobs such as line survey.