Principles of Satellite Positioning Reporting

This chapter shows the simplest layout for satellite positioning reporting, including one Measurement Control Center (MCC), two geostationary orbit (GEO) satellites, and a certain number of Calibration Stations (CS). Intersection measurement positioning of three spheres is the fundamental principle of satellite positioning reporting. The chapter describes the main factors affecting positioning accuracy. These factors are accuracy of satellite location, accuracy of MCC time delay measurement, accuracy of system equipment time delay, accuracy of space propagation time delay correction, relative location relationship between satellites and user, user elevation accuracy that may be provided by system or user and MCC location accuracy. The geometric figure of the user and satellite has great impact on positioning accuracy, which is generally expressed in Geometric Dilution of Precision (GDOP). Besides GDOP, there are another four factors as follows: position dilution of precision (PDOP); horizontal dilution of precision (HDOP); vertical dilution of precision (VDOP); and time dilution of precision (TDOP).