Theory of Carrier Adjusted DGPS Positioning Approach and Some ExperimentalResults (Met Fasemetingen Ondersteunde DGPS Plaatsbepaling: Theorie en Experimentele Resultaten)

摘要

The primary objective of this dissertation is to develop a new approach for realtime DGPS positioning. The dissertation starts in Chapter 2 with a review of the Kalman filter theory and the procedure of real-time model testing, followed by the concepts of internal and external reliability. In the next chapter, some existing algorithms for generation of DCs are discussed. By using the Kalman filter theory, Chapter 4 first derives an alternative algorithms for generation of DCs and next integrate the algorithms with a real-time quality control procedure. Chapter 5 investigates the validation of dynamic models chosen for DCs and for ionospheric delays, the dynamic behavior of code biases, the performance of the real-time model testing, and the accuracy of DC prediction. Chapter 6 investigates the relationship between satellite elevation and the precision of GPS code observations. Chapter 7 derives an alternative algorithm for DGPS positioning at a mobile station and show how positioning accuracies vary with the number of GPS observable used at reference and user stations and how the accuracy can be improved by choosing an elevation dependent, instead of constant, standard deviation for code observations. Chapter 8 extends the DGPS positioning research from the situation based on only one reference station to that based on a local DGPS network. Chapter 9, shows why and how we expand GPS observation equations into Taylor series which include only up to first-order derivative quantities. Finally, Chapter 10 summarizes some main conclusions of this research.