Performance Assessment of EGNOS 2nd Generation Navigation Land Earth Station

D. Kubrak and H. Al-Bitar

Abstract:	In a near future, EGNOS, the European Geostationary Navigation Overlay System, will be able to provide a new dual frequency service that is meant to replace the current legacy L1 mono-frequency service. To this end, different EGNOS sub-systems are being updated. Namely, new payloads are embarked onboard the ASTRA 4B and ASTRA 5B satellites. The latters were designed to provide a dual frequency L1/L5 signal. On the other hand, the NLES (Navigation Land Earth Station) is being updated too. The second generation of NLES, so-called NLES-G2, will replace the legacy NLES to transmit such dual frequency signal to the GEO transponder. Besides generating the EGNOS signal, the NLES is responsible for monitoring and controlling this signal emission at the output of the satellite transmission antenna phase center. The data message available at the satellite transmission antenna should indeed be synchronized to the EGNOS system time. The synchronization is performed by a Long Loop Algorithm (LLA) implemented within the NLES. The LLA estimates the propagation delays between the NLES and the GEO downlink antenna phase center. In the context of a dual frequency service, the LLA algorithm should be updated accordingly in order to maintain the SBAS service. The present paper focuses on the design and tradeoffs induced by the modification of this algorithm, and the associated performances obtained with the new NLES-G2 (G2 for second generation). The results show that a relative steering accuracy of ± 85 ns with COTS hardware and no complex calibration procedure is achievable.
Published in:	Proceedings of the 45th Annual Precise Time and Time Interval Systems and Applications Meeting December 2 - 5, 2013 Hyatt Regency Bellevue Bellevue, Washington
Pages:	306 - 314
Cite this article:	Kubrak, D., Al-Bitar, H., "Performance Assessment of EGNOS 2nd Generation Navigation Land Earth Station," Proceedings of the 45th Annual Precise Time and Time Interval Systems and Applications Meeting, Bellevue, Washington, December 2013, pp. 306-314.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In