Sept. 1, 2020
Description: Real-time precise point positioning (PPP) can provide submeter-to-centimeter level positioning solutions using a single GNSS receiver, which makes it a promising positioning technology for mass-market applications, such as autonomous driving, internet of things, location-based services. Real-time PPP relies on precise state-space representation (SSR) corrections from external service providers to mitigate different GNSS error sources, it is therefore essential to develop a real-time PPP correction service which can provide highly available and accurate SSR corrections. In this study, we developed a low-cost real-time PPP correction service to provide highly available and accurate SSR corrections, including satellite orbit, clock, differential code bias (DCB), global vertical ionosphere, regional slant ionosphere, and regional zenith wet troposphere. We developed innovative methods, algorithms, and technologies regarding the estimation, representation, dissemination, and application of the real-time SSR corrections to meet the demands of low-cost GNSS users in term of bandwidth, costs, measurement quality, etc. The developed correction service can support highly available real-time precise positioning during communication link corruptions for up to 2 hours and can also support rapid convergence to accurate positioning solutions even with low-cost GNSS chipsets and modules on mobile devices like smartphones. It therefore brings significant improvements to conventional real-time PPP systems which suffer loss of precise positioning solutions during correction outages and long convergence time. Figure 1 shows the overall design of the low-cost real-time PPP system based on the new correction service including the estimation and representation of SSR corrections at the server side, the dissemination of SSR corrections over communication links, and the application of the SSR corrections for real-time PPP at the user side.
Figure 1: Low-cost real-time precise point positioning (PPP) correction service with high availability and accuracy: Green for SSR corrections estimation and representation at the server side with GNSS observations from a reference network, Red for the dissemination of SSR corrections over telecommunication network or communication satellites, and Blue for the applications of SSR corrections for precise positioning of smartphones, self-driving cars and UAVs etc.
Funding sources: China Scholarship Council, Natural Sciences and Engineering Research Council of Canada
Link to thesis: http://hdl.handle.net/1880/111922