| Author: | Liu, Jiawei |
| Title: | Application of receiver autonomous integrity monitoring algorithms in urban environment |
| Advisors: | Chen, Wu (LSGI) |
| Degree: | M.Sc. |
| Year: | 2019 |
| Subject: | Slopes (Soil mechanics) -- Remote sensing Radar Hong Kong Polytechnic University -- Dissertations |
| Department: | Faculty of Construction and Environment Department of Land Surveying and Geo-Informatics |
| Pages: | viii, 71 pages : color illustrations |
| Language: | English |
| Abstract: | Integrity is a significant parameter to evaluate the GNSS performance, which initially proposed in aviation domain. It is defined as a measure of trust which can be placed in the correctness of the information supplied by a navigation system. Receiver Autonomous Integrity Monitoring (RAIM) algorithm is a technique to realize integrity control by means of observation redundancy instead of additional equipment. In decades, this concept has been introduced for other GNSS applications due to the growing demand for accurate and reliable positioning, especially in urban area. However, the technique cannot be applied in urban environment directly. As in open sky, aircrafts are able to receive large amount of visible satellites without obstructions. And the probability that two fault satellites occur is negligible. Consequently, RAIM was proposed based on a high redundancy and one-fault hypothesis. But the urban circumstance is quite different. Measurements are interfered by multipath contamination and non-line-of-sight reception on account of building obstruction. Simultaneous-multiple faults appear commonly, even become the majority of received signals in some severely signal-degraded conditions. The focus of this thesis is to apply RAIM technique for urban environment based on consumer-grade applications. A Recursive RAIM modified by the classic RAIM algorithm and a specific RANSAC RAIM derived from computer imaging have been realized. Dynamic data was collected from dual-constellation system (GPS and BDS) by a mobile phone in three practical scenarios (an open-sky location and two urban canyons). Test results of post processing demonstrates that RANSAC RAIM is competent to provide integrity control and significant improvement for urban positioning. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| 991022385444603411.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 2.11 MB | Adobe PDF | View/Open |
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