RART

This project focuses on the design, development and integration of a Range Authentication Receiver Testbed (RART) using a GOOSE© receiver platform.

The testbed supports the authentication of E1, E5a and E6 signals based on the Assisted Commercial Authentication Service (A-CAS) proposed by ESA. This is based on the encryption of the E6C pilot signalling component. The testbed processes the open live signals of the three bands and regularly performs snapshots of the digital samples. Encrypted PRN sequences of the E6C signals are provided with a certain delay, as provided for in the A-CAS use case.

With these sequences, it is possible to subsequently detect the encrypted signal in the snapshots and to authenticate the measurements provided by the open signals by comparing them with the measurements of the encrypted signals.

In addition, the testbed also supports the authentication of E1/E5a using simulated encrypted signals transmitted in the same band. This use case is not foreseen in the Galileo system, but is provided to increase flexibility and for evaluation against the E6C-only approach.

• Development of range authentication for OS signals as a supplement to OSNMA
• Development of multi-frequency snapshot techniques on GOOSE^©

• The time to first authenticated fix (TTFAF) based on the supported range authentication is achieved within 49 seconds after a cold start of the receiver.
• During runtime, a range authentication can be performed for two bands every 10 seconds.
• The E1BC signal achieves an accuracy of 75 m, while band E5a achieves an accuracy of approx. 15 m. For combinations of E1BC with E5a, as well as E1BC with E6BC or E5a with E6BC, the accuracy is approx. 15 m or around 30 m respectively.