Real Time GNSS networks established across countries over the last fifteen years, provide centimetre level accuracy for a wide range of applications differing from precise ship docking to land surveying. Public sector organizations deploy GNSS Networks to support infrastructure projects. Private companies establish their own networks for commercial or private use. The number of users of these networks has steadily increased over the years, and a potential new market has been created. This thesis focuses on the exploitation of the advantages of using multiple users operating within a GNSS network as part of the system, as a virtual network of stations that can operate autonomously and combined with the reference station network. A new network-RTK methodology that encompasses the multiple users of network RTK services for instantaneous positioning, is presented. Users are equipped with a means of two-way communication that enables the data to be transmitted to a central processing facility on an epoch by epoch basis. A centralised approach reduces the need for complex algorithms at the user side. The methodology is tested through the use of data from the South California Integrated GNSS Network (SCIGN) for two different network formations with different numbers of users operating simultaneously. It is shown that regional estimation of relative ionospheric corrections from the proposed methodology has a positive effect on the overall ambiguity resolution success rates when compared to the use of a standard ionospheric model. It is demonstrated that the use of the multiple rovers operating in the network increase the ambiguity success rates for the ones outside the network area by almost 20%. A smaller improvement for rovers near the boundaries of the network is also achieved. Finally, new prospects for regional atmospheric modeling become available, since the algorithm estimates all the double difference ambiguities for the reference station-rover system.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:625326 |
| Date | January 2010 |
| Creators | Zinas, N. |
| Publisher | University College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://discovery.ucl.ac.uk/19913/ |
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