Research On Pseudolite Navigation Positioning Algorithm

Satellite Positioning system,which can be used worldwide 24 hours a day under any weather,are representations of most advanced positioning systems.Most developed countries and some other countries are doing their own studies and developments for this kind of system.Reprensented by GPS of the US and GLONASS of the Russia,the second generation of Satellite Positioning system is extensively used for many purposes.Apart from GPS and GLONASS,different kinds of augmentation systems like DGPS, WADGPS and GNSS-1 have also been developed.Being a big and important country in the world,China still does not have its own Satellite Postioning system that can cover the whole world.called beidou,the china's Satellite Positioning system that is under development can only provide services in and around china's own tenitory.Theoretically, it is required that GPS user has to track at least four Satellites for Positioning.This means that constellation must provide four or more layer over its coverage area.Because user are always locate in different circumstance,in practise,layers required for service must be increased.This thesis put forward the solution with GPS-pseudolite integration for three dimensional positioning.In this thesis ,we introduce the concept of pseudolite and the Navigation position algorithm.Next, constellation model of a satellite postioning system is set up,positioning calculation using D-R algorithm is discussed.we emphasize on the feasibility of positioning algorthm .After that,based on positioning theory,precision of positioning is discussed and dilution of positioning of the D-R algorithm is defined.The parameters that affect the figure of DOP are then discussed.Simulation results show that D-R algorithm can be used under certain restrictions.