Journal of Navigation and Port Research (한국항해항만학회지)

Korean Institute of Navigation and Port Research (한국항해항만학회)
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Analysis of LDC Message Reception Performance of Korean eLoran Pilot Service according to Modulation Methods

첨단 지상파항법시스템(eLoran) 시범서비스의 LDC 메시지 변조기법에 따른 수신성능 분석

  • Pyo-Woong, Son (Korea Research Institute of Ocean and Ships Engineering, University of Science and Technology) ;
  • Sak, Lee (National Maritime PNT Office) ;
  • Tae Hyun, Fang (Korea Research Institute of Ocean and Ships Engineering) ;
  • Kiyeol, Seo (Korea Research Institute of Ocean and Ships Engineering)
  • 손표웅 (선박해양플랜트연구소, 과학기술연합대학원대학교) ;
  • 이삭 (국립해양측위정보원) ;
  • 황태현 (선박해양플랜트연구소) ;
  • 서기열 (선박해양플랜트연구소)
  • Received : 2022.11.15
  • Accepted : 2022.12.02
  • Published : 2022.12.31
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Abstract

In the eLoran system, the Loran Data Channel (LDC) is used to provide precise timing and positioning. The LDC message can be modulated with the Eurofix method, which modulates the transmission time of the 3rd-8th pulse not used for navigation, and the 9th pulse method, which modulates data using the 9th additional pulse after the existing 8 Loran pulses. In this paper, we analyzed the reception performance of the LDC message transmitted from the eLoran transmitter according to the modulation method. The eLoran testbed transmitter in Incheon was set to transmit LDC messages simultaneously with the 9th pulse modulation method and the Eurofix modulation method. Then, the LDC messages stored in the databases of the eLoran differential stations in Incheon and Pyeongtaek were analyzed in terms of the message reception rate according to the modulation method. Using the navigation aid management ship Inseong No. 1, the range of LDC message reception of actual sea users near Incheon Port was also analyzed. The results of this study are expected to be utilized in the full operational capability service after the eLoran pilot service.

eLoran 시스템에서 보다 높은 정확도로 시각 및 위치 정보를 제공하기 위해 별도의 데이터 채널인 Loran Data Channel (LDC)를 사용한다. LDC 메시지는 기존의 8개의 Loran 펄스 중 항법에 사용하지 않는 3-8번째 펄스의 전송시각을 변조하여 송출하는 Eurofix 방식과 9번째 추가 펄스를 이용해 데이터를 변조하는 9th 펄스 방식으로 변조될 수 있다. 본 논문에서는 eLoran 송신국에서 송출하는 LDC 메시지의 변조방법에 따른 수신 성능을 분석하였다. 인천에 설치하여 시범운영 중인 eLoran 시험 송신국에서 9th 펄스 변조방법과 Eurofix 변조방법으로 동시에 LDC 메시지를 송출할 수 있도록 설정하고, 인천과 평택의 eLoran 보정기준국의 데이터베이스 내 저장된 LDC 메시지를 분석해 변조방법에 따른 LDC 메시지 수신률을 분석하였다. 또한 항로표지 관리선 인성 1호를 이용해 인천항 인근에서 실제 사용자의 LDC 메시지 수신률을 분석하였다. 본 연구결과는 향후 정식 eLoran 서비스 과정에서 공식적인 LDC 방송 메시지를 확정하기 위한 기술자료로 활용될 수 있을 것이다.

Keywords

Acknowledgement

본 논문은 해양수산부의 지원으로 수행된 "첨단 지상파항법시스템 (eLoran) 기술개발 [PMS4020]" 과제와 "지상파 통합 항법시스템 (R-Mode) 기술개발 [PMS5030]" 과제로 수행된 연구결과입니다.

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