Research On Real-time Stream Based Data Management Of GNSS Integrated Application System

GNSS Continuously Operating Reference Station (CORS) Network can provide not only precise fast positioning service but also spatial infrastructural information which could be utilized in geodesy, meteorology, geophysics, city planning. GNSS CORS Network has been a trend globally; in China, some cities have also built or are building similar networks. To investigate and study such system and to assist the construction of Beijing GNSS Integrated Application System (BGIAS), I investigated similar systems in and across the country. According to the requirements of BGIAS, I studied the real-time stream based GNSS data management methods.This thesis introduces the status of both Chinese and foreign GNSS CORS Network, elaborating the architecture and data service of BGIAS. Due to the wide user range, various kinds of data service, huge amount of data storage, traditional file-based data management fails to meet the requirements of the system. To solve this problem, this thesis analyzes the data of CORS and put forward a real-time stream based data management method basing on the platform of large-scale relational database management system (RDBMS). This thesis elaborates both the file based data management method and the stream based method, comparing the pros and cons of both methods. Finally, BGIAS employs mainly the stream based method and complementarily the file based method. This solution increases the responsiveness and flexibility of the data service, decreases the data redundancy, and consequently increases the service performance of the system. Since this method was rarely reported in GNSS CORS Network, the key technical difficulties of the software subsystem of BGIAS are studied and a set of programs are developed which have been deployed in the BGIAS Test System (BTS). At this time, BTS has been deployed and has been running steadily for several months and providing data service to users. The thesis also introduces the database design, RDBMS platform choice, data distribution modes, key problems and solutions of the software development, and the validity, precision, and robustness test results.