High-precision Gps Data Processing Several Theoretical Research, And Technical Issues

Global Positioning System is widely used in geodesy and survey engineering. With the development of GPS, precision becomes more and more important for surveying. For GPS control network, baseline solution precision is the basic factor of the control points precision. Basing on the precision of baseline solution, the main factors relating to high precision GPS data processing, in this paper, GPS phase observation equation, atmosphere refraction correcting, ephemeris errors, adjustment datum, reference frame are systematically studied. The main research works are following:Analyzing systematically zero difference phase observation equation. Discussing and studying with different observation vectors and their lineal combination models and apply. Introducing the theories of atmosphere refraction and correcting methods, and comparing differences of all kinds of zenith delays and projection functions. Analyzing and comparing the estimation technique used for the atmosphere affection in GPS baseline estimation. Derive of the methods of correcting atmosphere errors to different scope GPS net.Introducing the user algorithm of the broadcast ephemeris, the algorithms are explained on principle, which are Lagrange Interplation and Chebyshev polynomial simulation. Then comparisons of calculating of satellite coordinate with broadcast ephemeris and with precise ephemeris are made. Through example, analyzing positioning precise influence which broadcast ephemeris and precise ephemeris process different length baselines.Reference frame's uniformation methods, adjustment methods and the implication of corresponding datum for various adjustment methods are systematically discussed about high precision GPS network. The systematical investigates on the choice of reference station in the high precision GPS data processing and the effect to adjustment results are made. Some general principles on the choice of reference station are presented.