Precise Positioning for Mass-Market: Optimal Data Dissemination DAB+ Demonstrator

Abstract

The main issue in the development of precise positioning is the way in which to send GNSS corrections. To handle this case, a terrestrial broadcast mechanism based on DAB+ (digital audio broadcasting) signals was chosen to overcome the scalability challenges, as it would allow a service provider to transfer assistance data based on a “one-to-many” scheme. DAB is easily widely deployed, with large coverage predictions carried using ATDI’s HTZ simulator. The DAB+ reception demonstrator uses SSRZ, a compressed and compact state space representation corrections format developed by Geo++. SSRZ corrections were generated using data from Teria’s CORS network and have been broadcasted over the air with DAB+ signals. To validate the SSRZ corrections, the “Record&Replay” technique was used. It consists of digitizing GNSS signals during a normal field test. Once data were collected and validated, replays were executed in the laboratory. Different scenarios were set up to validate the accuracy of the position with SSRZ corrections sent via DAB+ and the convergence to the corrected position after ambiguity loss. The results show that the accuracy was acceptable when the user remained close to the transmitting DAB+ antenna (<10 km). The lower performance might result from broadcast limitations in urban environments.

Keywords

• SSR
• DAB+
• NRTK
• PPP-RTK