Accuracy Test And Evaluation Analysis For GPS/RTK Network

The differential positioning of network GPS/RTK technology is the most important application of CORS,it integrates with computer technology,network technology, communication technology and GPS technology,and achieves high accuracy, reliabilty and efficient real-time GPS positioning. Compared with normal RTK, GPS network RTK has the advantage of wide range of services, high positioning accuracy and reliability.Currently,GPS Network RTK technology has been widely used in various industries.The content involved in this paper is part of researching work during author' postgraduate stage.The paper firstly elaborate the necessity of network GPS/RTK researching in the background of the development of GPS technology based on which the paper introduces in detail the basic theory and composition of the network GPS/RTK technology, mainly including system components,basic principles and key technologies and also analyzes and compares several network RTK widely used currently.Then the paper innovatively devides the errors that affect positioning accuracy of the network GPS/RTK into errors related into reference station, atmospheric transmission,GPS receiver, satellite and communications, all of which will makes it have a clear structure.Then various error sources that affect the precision of networkd RTK is analyzed and discussed in detail,and also the method and measures that can eliminate or weaken error sources is concluded.Finally, the paper analyzes in detail the testing contents of multi-based station network GPS/RTK system, and summes up a complete set of network GPS/RTK system test analysis, and also briefly introduces the associated test methods.Above this,taking the GPS satellite positioning network service system in some province as the test target,the paper completes the design of accuracy testing plan of the entire CORS network with VENUS software developed by Dingfa Huang professor of SWJTU and GPSNET software Developed by Trimble company.because of the large coverage of CORS network in this province and heavy workload of outside field,it is extremely important to degign a reasonable and scientific implementing plan of the program according to actual situation.Based on the plan, the paper analyzes the internal fitting precision,external fitting precision,time availability, internal differential uniformity,the relationship between external differential accuracy and distance,mobile performance and timeliness of positioning services based on the data collected from six base stations of CD,ZJ,PX,JY,RSH and QL. The collecting time continues more than 20 days. With the testing result,the paper completes the preliminary evaluation of the performace of the CORS network based on VENUS and GPSNET within this province region,and meanwhile the paper compares and analyzes these two test results of VENUS and GPSNET system and completes corresponding conclusions.