eLoran: New Interest in Radio Navigation Technology after GPS Jamming Incidents
Recent incidents of GPS interference and jamming and the possibility of cyberattacks have renewed interest in earth-based radio navigation systems.
South Korea, the US, Russia, and Britain have all independently been exploring Enhanced Long Range Navigation, or eLoran, with the aim of updating the decades old radio navigation technology first developed during WWII.
Incidents of GPS jamming have increased since 2014. In 2016, hundreds of South Korean fishing boats had to return to port after their GPS systems were jammed, they say, by North Korea, and multiple ships reported GPS system disruption in the Black Sea as recently as June of this year.
According to a Reuter’s article, 90% of global trade is still transported by sea, and unlike airplanes, ships often don’t use a backup navigation system, so interference of Global Navigation Satellite Systems (GNSS) like GPS can be both disruptive and dangerous. eLoran would function as an earth-based backup navigation system in the event of GNSS disruption.
GNSS vulnerabilities have been known for years. GPS and similar navigation systems use weaker signals originating from satellites 12,500 miles above the Earth, and those signals are susceptible to both natural interference (weather effects) and deliberate interference (GPS signal spoofing and jamming).
eLoran is considered a good choice for a backup navigation system because it uses a powerful signal, 1.3 million times stronger than the average GPS signal, that would be more difficult to jam. Jamming this signal would require a powerful transmitter, large antenna, lots of power, making those attempting interference visible and easy to detect. Spoofing would also be more challenging because the transmitters are land-based, limited in number, and they stay in fixed positions.
Countries whose ships have felt the effects GNSS interference, either natural or deliberate, understand the need for a reliable backup navigation system, but getting those countries around the world to commit to the costs of setting up and maintaining transmitter stations is a problem. Without many countries and a network of transmitter stations supporting the effort, eLoran coverage will not be global but only available in some regions.
South Korea is currently leading the way with eLoren exploration. Three South Korean eLoren test sites are planned to be operational by 2019.