GPS Precise Point Positioning Algorithms And Its Applications

Precise Point Positioning refers to the method of using the observation data from global GPS Tracking Station to calculate out Precise Satellite Orbit and Precise Satellite Clock Error and then using the collected observation data from Pseudorange and Carrier Phase by a single piece of GPS receiver to obtain the solution. By means of Precise point Positioning, we can calculate the receiver clock error, troposphere zenith delay parameters besides the coordinate of outside stations,which can satisfy the needs of different users. Therefore, the Precise Point Positioning technology has a bright prospect.This paper introduces the Precise Point Positioning Theory, and then does research on some key problems about Precise Point Positioning.It mainly studies as follows:1. Un-differenced observation equation and its error source This paper introduces un-differenced observation equation and discusses the main error sources in Precise Point Positioning, including satellite orbit error, satellite clock error,troposphere delay,ionosphere delay, receiver clock correction and multipath effect etc.It aslo discusses the method of eliminating or weakening those effects.2.Processing methods of Precise Point Positioning Based on the observed equation of Ionosphere-free Combination in the Precise Point Positioning,this paper discusses the related data processing problems, including un-differenced base pretreatment, parameter estimation method, etc.And then it obtains the analysis of results from the data and the static positon accuracy at cm level. This accuracy are quite comparable with the results from both the domestic and foreign countries.3.Meteorological application of Precise Point Positioning Compare tropospheric zenith delay parameter estimated from Precise Point Positioning technology with the troposphere delay products provided by IGS. The results indicate that by using the Precise Point Positioning technology, we can estimate tropospheric zenith delay at millimeter level. At the same time, this paper introduces the process of precipitable water vapor and selects the observed monthly data from stations to do the reasearch on water vapor, and, lastly, concudes that precipitable water vapor and the observated data from the radio sonding are of good consistency.