eLoran - Alternative PNT for submerged and GNSS denied environments
eLoran is the latest version of the Low Frequency PNT system Loran and identified as the most suitable terrestrial Alternative PNT system to back up GPS and other GNSS. eLoran provides the same sort of PNT information (horizontal positioning up to 10 meters and better than 100 ns traceability to UTC in its most accurate implementation) using a completely different part of the radio frequency spectrum. The dissimilarity of systems makes eLoran a perfect candidate as a robust alternative to satellite systems where they are denied or otherwise unavailable.
The use of high-power Low Frequency signals also makes eLoran penetrate sea water to enable absolute positioning capabilities in submerged conditions. Loran is an internationally standardized system and despite the reduced interest in the western world is used, expanded and modernized in other parts of the world (South-Korea, China, Russia, Saudi-Arabia and the UK).