Investigation Into Quality Control And Integrity Monitoring For VRS Technique

Recently, according to the requirements of some important research subjects and practical applications in terms of real-time positioning with high-precision and reliability in the fields of precise navigation, deformation monitoring and real-time spatial information service, we GPS Group studied the web-based enhanced VRS technique as well as its quality control and integrity monitoring systematically, and also brought out a self-developed system, namely VENUS (Vrs-Enhanced Network Utility Solution), which is based on enhanced VRS technique. As the parts of the main contributions, the research projects focus primarily on the quality control and integrity monitoring of the VENUS system.The main contents of this thesis consist of two parts:First part-the outline of the research background and the systematic introduction and summarization of the previous research of this work.Second part-the main contributions and research results of this paper are focused on as follows:(1) Study on real-time quality control for the observations. Given the requirements to the quality control for VRS technique, the data synchronization, clock jump, pseudorange phase-smoothing and ephemeris monitoring are discussed and analyzed, and then a new algorithm for cycle slip on-line detection in reference station network based on (9,-7) linear combination and Kalman filter is proposed, then an experiment is conducted to prove its correctness and effectiveness.(2) Study on integrity monitoring for VENUS system on the basis of SIGN data platform. An overview of the double-differenced ionospheric delay as well as tropospheric delay in terms of spatial and temporal dependence are illustrated firstly, then a weigted low-order surface model is selected to predict the spatially correlated errors in the mobile user. Based on the above analysis, two indicators for the integrity monitoring in double-differenced ionospheric delay are computed, including Ionospheric Residual Integrity Monitoring (IRIM) and Ionospheric Residual Interpolation Uncertainty (IRIU); and two indicators for the integrity monitoring in double-differenced tropospheric delay, called Tropospheric Residual Integrity Monitoring (TRIM) and Tropospheric Residual Interpolation Uncertainty (TRIU), are proposed to predict the tropospheric linearity, whereafter an experiment are canied out to test the performance of the above indicators with the data in SIGN. The results show that, the indictors can perfectly represent the errors "seen" by the rover thus they are the useful tools to predict the rover performance in VENUS system. Simultaneously, an approach has been put forward for monitoring the multipath residuals of MW linear combination which experience sidereral filitering. Taken the above investigation into account, the architecture for the integrity monitoring in VENUS system has been designed in detail.