The Research And Application Of GPS Phase Smoothing Pseudorange Differential Positioning Technology

In recent years, the technique of GPS has not only been widely applied in such usual fields as surveying and mapping, geology, mining, and water and electricity, but also in such special fields as police, fire protection, tour, and exploration. At present, the technology of Pseudorange Differential GPS (PDGPS) has become the hottest research topic in accordance with the real-time and different precision requirement of the special fields. Hence, the PDGPS technique and its application, including the DGPS technique of phase smoothing pseudorange, are deeply researched in this paper, and the positioning software of phase smoothing PDGPS is compiled. The chief research contents in the paper are as follows:1. The developmental status of GPS and PDGPS are briefly introduced, then the research aim and meaning about the positioning technique of PDGPS are discussed.2. The basic observable of GPS and the mathematic models of pseudorange point positioning are researched. Meanwhile, The positioning errors of GPS and its correction models are discussed at length, Particularly the practical example with regard to satellitic ephemeris error is computed and analyzed.3. The positioning theories and mathematic models of PDGPS, including usual PDGPS, combined PDGPS and phase smoothing PDGPS, are described and demonstrated in detail. The required theory of cycle-slip detection in phase smoothing pseudorange is researched, and the practical example is also used. Moreover, the theoretical model concerning coordination transfer is introduced in this chapter, too.4. The positioning software of phase smoothing PDGPS, which have the functions of inputting, calculating, editing, analytic and outputting of data, is developed successfully. On the basis of understanding deeply the positioning theories and mathematic models of PDGPS, the general structure, models and functions of the positioning software of phase smoothing PDGPS are designed. The organization and realization of data resources of the software are researched profoundly, which make the interface problems between the software and other ones solved successfully. Of course, the realization process of the software is also expatiated concretely.5. After the testing data of GPS are processed by means of the positioning software of phase smoothing PDGPS compiled by Visual Basic 6.0, and the testing results are analyzed and researched detailedly, some useful and important conclusions are obtained. For instance, the DGPS technique of phase smoothing pseudorange is an ideal one in (approximate) real-time positioning ways. Besides, the reliability and practicability of the software are validated adequately.