eLoran Initial Operational Capability in the United Kingdom – First Results

Gerard Offermans, Erik Johannessen, Stephen Bartlett, Charles Schue, Andrei Grebnev, Martin Bransby, Paul Williams, Chris Hargreaves

Peer Reviewed

Abstract:	There is an increasing awareness in the Maritime world that no single system can provide Position, Navigation, and Time (PNT) resiliently under all circumstances. At this moment GPS (with augmentations) is used on most commercial vessels, and in many cases integrated into systems we did not expect would need or use GPS derived position or time. Even though the introduction of Glonass, Galileo, Beidou and other GNSS systems will provide some resilience, the underlying (satellite) technology remains the same, only providing relatively weak signals from space at mostly the same frequencies for compatibility and inter-operability. The International Maritime Organization (IMO) recognizes the need for multiple PNT systems on board. The organization developed the e-Navigation concept to increase maritime safety and security via means of electronic navigation, which calls for (at least) two independent dissimilar sources of positioning and time in a navigation system to make it robust and fail safe. As a follow on, IMO’s Navigation, Communications and Search and Rescue Committee (NSCR) is considering Performance Standards for Multi-System Shipborne Navigation Receivers, which includes placeholders for satellite, augmentation and terrestrial systems. The most viable terrestrial system providing PNT services that meet IMO’s requirements is eLoran. With three eLoran transmitters in good geometry, eLoran can provide sub-10 meter (95%) horizontal positioning accuracy and UTC synchronization within 50 ns, sufficient to be the co-primary PNT solution next to GNSS. The General Lighthouse Authorities of the United Kingdom and Ireland (GLA) have installed Differential eLoran Reference Stations to provide the world’s first Initial Operational Capability (IOC) eLoran system. Together with Loran transmitters in England, France, Germany and Denmark, the Differential eLoran Reference Stations provide better than 10 meter positioning accuracy at seven ports and port approaches along the English and Scottish East Coast. Initial Operational Capability was declared by the end of October 2014 with Full Operational Capability planned for 2018. Other nations have begun similar projects. The paper describes the IOC eLoran system in the UK, consisting of Differential eLoran RSIMs covering seven major ports in England and Scotland. ASF maps for the port and harbor approaches are published by the GLAs for integration into maritime user equipment. The paper provides initial static (zero-baseline) and dynamic measurement results at the harbor and harbor approach areas.
Published in:	Proceedings of the 2015 International Technical Meeting of The Institute of Navigation January 26 - 28, 2015 Laguna Cliffs Marriott Dana Point, California
Pages:	27 - 39
Cite this article:	Offermans, Gerard, Johannessen, Erik, Bartlett, Stephen, Schue, Charles, Grebnev, Andrei, Bransby, Martin, Williams, Paul, Hargreaves, Chris, "eLoran Initial Operational Capability in the United Kingdom – First Results," Proceedings of the 2015 International Technical Meeting of The Institute of Navigation, Dana Point, California, January 2015, pp. 27-39.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In