Error Analysis of GPS Positioning

This paper reviews the development and functions of the space segment,ground-control segment and user segment of GPS together with the basic principle of GPS positioning.Errors in GPS positioning are determined by PDOP and measurement errors of the distances between GPS satellites and a user.Measurement errors of the distances consist of three categories of errors:the errors in orbit prediction,and time calibration of GPS satellites,errors in GPS signal propagation,and those due to receiving equipments.This paper gives a systematic and comprehensive analysis of these errors,and proposes specific models for correcting or even eliminating these errors.