Korea institute awards UrsaNav an eLoran test bed contract

August 28, 2018  - By
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The Korea Research Institute of Ships and Oceans Engineering (KRISO) has awarded UrsaNav a contract to supply an eLoran Transmitter Test Bed System in the Republic of Korea.

UrsaNav, the exclusive, worldwide distributor of Nautel’s NL Series transmitters, will provide eLoran transmitter technology, as well as timing and control equipment.

A meeting to kick off the eLoran work. (Photo: UrsaNav)

A meeting to kick off the eLoran work. (Photo: UrsaNav)

The contract, awarded through UrsaNav’s agent Dong Kang M-Tech, represents the first phase in a broader program to upgrade Korea’s Loran-C stations to be the foundation of a sovereign Enhanced Loran (eLoran) positioning, navigation and timing (PNT) service.

The Republic of Korea recognizes the challenges associated with relying solely on space-based signals, the relative ease with which those signals can be jammed or spoofed, and the necessity to provide trusted time and position to its citizens and critical national infrastructure, UrsaNav said in a press release.

The press release also included the following description of the importance of eLoran.

Accurate time and position are necessary components upon which many critical infrastructure sectors rely, including maritime, aviation, electrical distribution, telecommunications, finance/banking, and digital broadcast. A complementary PNT (CPNT) service provides continuity of operations through alternative and diverse timing and positioning information. CPNT is a vital element in ensuring national security and assuring Trusted Time and Trusted Position.

eLoran is the latest in the longstanding series of low-frequency (LF), LOng-RAnge Navigation (LORAN) systems. It meets the accuracy, availability, integrity, and continuity performance requirements for maritime harbor entrance and approach maneuvers, aviation En Route and Non-Precision Approaches, land-mobile vehicle navigation, and location-based services. It provides bearing (azimuth) information, even when the user is not moving, and has built-in integrity. Users within the coverage area can simultaneously synchronize their timing to absolute (not relative) UTC. Of equal importance is that the eLoran signal includes one or more Loran Data Channels that are available to provide one-way, low data rate, “Short Message Service” information.

eLoran is completely independent of GPS/GNSS, operates in the internationally protected 90 to 110 kHz spectrum, is built on internationally standardized Loran-C, and provides a high-power PNT service for use by all timing and navigation users. SAE International expects to release eLoran standards this year. The RTCM also has maritime-related eLoran standards underway.

eLoran is a key vertex of a Resilience Triad that would typically include space-based, terrestrial, and at least one other PNT source. It is a very-wide area (i.e., country-wide or “continental”) source of PNT that continues providing a resilient solution even when GNSS may be unavailable or untrustworthy. eLoran delivers information comparable to that of GNSS, but with completely different phenomenology. It is a very high-power, LF, pulsed transmission, whereas GNSS are low-power, UHF, multiple modulation scheme transmissions. eLoran is literally at the other end of the spectrum from GNSS, and has completely dissimilar failure modes. That is, an issue that disrupts GNSS is unlikely to disrupt eLoran. The unique characteristics of eLoran enable its use in environments where GNSS does not work very well, or at all (e.g., indoors, underwater, underground, and in mountain or urban canyons).

eLoran is exceptionally difficult to spoof or jam, and it is nearly impossible to do so at a distance. Just as equipment required to spoof and jam GNSS must mimic relatively low powered GNSS transmissions, spoofing and jamming eLoran requires very high powered transmissions. Equipment needs alone to disrupt eLoran over a significant area would be almost prohibitive for any actor other than a nation state engaged in open conflict. This is the reason that an independent assessment by researchers at Stanford University described eLoran as “for all practical purposes, unjammable” across any significant area. A MITRE paper concluded: “The analysis shows a very low probability of successfully producing operationally significant interference.”

About the Author:


Tracy Cozzens has served as managing editor of GPS World magazine since 2006, and also is editor of GPS World’s sister website, Geospatial Solutions. She has worked in government, for non-profits, and in corporate communications, editing a variety of publications for audiences ranging from federal government contractors to teachers.

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