Intelligent Acquisition And Engineering Application Of IGS Service Data

With the development of GNSS,the international GNSS service(IGS)is also advancing with the times.Since 1994,IGS has provided high-quality data and product services to research institutes and individuals worldwide within the global,supporting a wide range of scientific research,educational services and multidisciplinary applications.At present,there are many research institutions and GNSS individual users using IGS data and products to carry out scientific research and precise point positioning.This essay firstly introduces the digital model of precise point positioning and the main sources of its error,and then introduces the use and research status of IGS data and products,summarizes the origin,development and operation mechanism of IGS service organization,and systematically analyzes all kinds of data and products provided by IGS data center,finally make up the software to realize the acquisition of IGS data,and further processing and analysis of the acquired data.Specific research contents and results are as follows:(1)The IGS service data acquisition software is completed.Based on the analysis and understanding of the data and products released by IGS,based on the thinking of object-oriented analysis and design,combined with the modular programming idea,based on VS2013 platform,using C ++ programming language,designed and developed the MFC applications,realizing the development of the software.And established the corresponding database to meet the data storage and management functions.(2)Using the mathematical statistics method,analysis the statistical precision of the broadcast ephemeris.The experimental results show that Block-?F and Block-?RM satellites have higher orbit accuracy comparable to that of Block-?R satellites.The satellite clocks on the three satellites are equally accurate,with an overall accuracy better than 6ns,But in the short-term stability,rubidium clock is better than cesium clock.(3)Set up the IGU precision orbit real-time error model,and get the approximate function relation between the pre-push time and pre-push orbit error,which is y=0.2055 t+ 2.2986.The parameters of coordinate transformation of different analysis centers were calculated by using seven parameter conversion model to eliminate the systematic deviation between products,to analysis the precision of different analysis center products,and conclude that the data and products from the ESA and the GFZ is better than others,so we can combine the data from the two analysis center to replace the data and products from the IGS.(4)The IGS service data and products are used for precise point positioning,analyzing the influence of different system data on the accuracy of precision point positioning and the influence of data and products of different analysis centers on the accuracy of precision point positioning.The feasibility of the framework transformation is verified by the ITRF framework transformation example.