| Author: | Ng, Hoi Fung |
| Title: | 3D-mapping-aided GNSS real-time kinematics in urban environments |
| Degree: | M.Sc. |
| Year: | 2021 |
| Subject: | Artificial satellites in navigation Global Positioning System Hong Kong Polytechnic University -- Dissertations |
| Department: | Department of Mechanical Engineering |
| Pages: | vi, 67 pages : color illustrations |
| Language: | English |
| Abstract: | Global navigation satellite system (GNSS) has become an essential technology for our daily life. Different location-based service (LBS) relies on GNSS to provide an all-time function reliable and precise positioning with wide area coverage. Real-Time Kinematic (RTK) GNSS is one of the most precise positioning technologies currently, which provide centimetre-level accuracy positioning for an application operating in an open-sky environment, such as a geodetic survey. However, GNSS signal can be blocked or reflected by the high-rise buildings in urban canyons, limiting the positioning performance in deep urban canyons. Blockage and reflection of the GNSS signal result in non-line-of-sight (NLOS) reception, multipath, and cycle slip effect. These errors introduce large localization error. Therefore, removing bad measurements become essential to enable RTK GNSS positioning in the urban environment. Using the 3D building model is the common and state-of-art method to identify the unhealthy satellite, namely 3D mapping aided (3DMA) GNSS. We believed that using the 3D building model can better exclude the NLOS satellite compared to a fixed high elevation angle mask. In this study, the concept of 3DMA GNSS will be adopted to RTK GNSS positioning, namely 3DMA GNSS RTK. This study proposes using a 3D building model with position hypothesis candidates to select healthy satellites for RTK positioning. Designed experiments are set up with actual raw GNSS measurement to examine the performance of 3DMA GNSS RTK. Geodetic- and commercial-grade receivers are employed to perform experiments in the urban environment of Hong Kong. Experiment results with geodetic-grade receiver datasets show that 3DMA GNSS RTK can provide a positioning accuracy with a 10cm averagely in the urban area. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| 5935.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 3.29 MB | Adobe PDF | View/Open |
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