The SIGNATURE (SImple GNSS Assisted & TrUsted REceiver) project is prototyping a GNSS-based solution for road applications which provides a high integrity, or trustworthy, solution in a cost-effective and scalable manner. It demonstrates that a robust positioning solution offering high availability and integrity, even in demanding urban environments, can be based upon low-cost GNSS components. Demonstrating the performance of GNSS solutions is critical to support its adoption as the core technology for applications such as congestion management, fair and flexible road pricing, and pay-as-you-drive insurance.
The SIGNATURE solution includes an assistance service which provides ephemeris data and corrections from the EGNOS Data Access Service (EDAS), optimized for the user location. The onboard unit (OBU) hosts a bespoke receiver which exploits the continuous availability of assistance data and does not attempt to decode navigation data directly from satellite signals. This allows its design to focus on rapid signal acquisition with high sensitivity and to achieve a rapid time to first fix (TTFF) even in areas where conventional receivers struggle. Measurement data from the receiver is then processed with an application-specific navigation algorithm on the OBU which aims to improve the integrity of the position solution relative to standard solutions. The position data from the OBU is assessed by processing it with a Map Matcher once it has been transferred back to the Service Centre. This makes it possible to assess whether improvements in the OBU position output are significant in terms of matching the vehicle location successfully to road segments more reliably and for more of the journey.
More information at www.nsl.eu.com/SIGNATURE/index.html