Compass RDSS Positioning Accuracy Analysis

The RDSS service is an important component in the Compass system, which is accomplished by the GEO satellites with the restriction of known elevation. The RDSS observation model was deduced, and the positioning model was given with the elevation restriction. RDSS positioning tests were implemented with real observation data, the results were as follows: (1) the PDOP value was improved greatly to 1.5, with elevation restriction; (2) the RDSS observation noise is about 0.6 ns, which was greater than the pseudoranging and phase ranging in the RNSS; (3) the horizontal accuracy could reach 4.6 m in the Beijing region; (4) the main factors influenced the positioning accuracy include the elevation error, the time delay of both satellites and ground equipment, therefore in order to realize 10 m horizontal position accuracy, the elevation error should be less than 10 m, and the equipment time delay should be less than 10 ns.