First Demonstration of the Korean eLoran Accuracy in a Narrow Waterway Using Improved ASF Maps

TL;DR

This paper demonstrates the first operational Korean eLoran system in a narrow waterway, proposing an improved ASF mapping method to enhance navigation accuracy and validating its effectiveness through experiments.

Contribution

It introduces a novel approach for surveying ASF in narrow waterways and improves ASF map generation for eLoran, addressing practical challenges in such environments.

Findings

Successful deployment of Korean eLoran system since June 2021

Proposed ASF survey method improves map accuracy in narrow waterways

Experimental validation confirms enhanced navigation performance

Abstract

The vulnerabilities of global navigation satellite systems (GNSSs) to radio frequency jamming and spoofing have attracted significant research attention. In particular, the large-scale jamming incidents that occurred in South Korea substantiate the practical importance of implementing a complementary navigation system. This letter briefly summarizes the efforts of South Korea to deploy an enhanced long-range navigation (eLoran) system, which is a terrestrial low-frequency radio navigation system that can complement GNSSs. After four years of research and development, the Korean eLoran testbed system has been recently deployed and is operational since June 1, 2021. Although its initial performance at sea is satisfactory, navigation through a narrow waterway is still challenging because a complete survey of the additional secondary factor (ASF), which is the largest source of error for eLoran, is practically difficult in a narrow waterway. This letter proposes an alternative way to survey the ASF in a narrow waterway and improve the ASF map generation methods. Moreover, the performance of the proposed approach was validated experimentally.