• Journal of Navigation and Port Research
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• v.37 no.3
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• pp.275-281
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• 2013

Ship Standard Network was submitted as a common subject of e-navigation by 81th IMO MSC 2005. This agenda was given an official status with strategy planning of e-navigation for Ship Standard Network after approval of WG program of 81th MSC 2006. Nowadays approximately 400 heterogeneous navigation and communication equipments are working on ships at sea. Standardization of ship network is to support exchanging various data efficiently. Among them, 4S network is defined as a wireless communication network between ship to ship and ship to shore which provides unceasing communication channel ship to shore. It has been expected to trigger various services and applications based on 4S network. However, no technologies and products has been appeared at fields yet. but now there's not specific technologies and developing products. In this paper, We developed a 4S multiple media switching server and a ship-land information exchange system to overcome the heterogeneity and provide efficient communication environments.. The performance of the implemented system was verified by TTA(Telecommunications Technology Association) V&V(Verification and Validation).

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.201-203
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• 2013

선박의 출항부터 입항까지 전 과정에서 선박 안전과 보안 및 해양환경 보호 증진을 목적으로 선박과 육상 관련 정보의 수집, 통합, 교환, 표현 및 분석을 수행하고자 하는 e-Navigation 정책 하에 북유럽에서는 선박들 간 및 선박 대 육상 간 Way Point로 구성된 선박의 Route 정보를 교환하여 항행정보로 사용하는 개념인 Route Exchange 방안을 연구 중으로 향후 e-Navigation 시스템에서는 선박통합항행시스템의 주요 기능으로써 구현 및 현 VTS 관제 방식에도 큰 변화를 가져올 것으로 예상된다. 이에 따라 이 연구는 북유럽에서 선행 연구 중인 Route Exchange 개념을 소개하고 실제 사고사례를 통해 Route Sharing의 필요성을 제기하며 항만과 연안 VTS 관제 해역 내 적용 시에 고려되어야 할 문제점 및 방향성 제시와 함께 시급히 개선되어져야 할 관제장비 기능에 대하여 소개함으로써 관제해역 내 적정 Route Exchange 도입방안을 모색한다.

• Journal of Navigation and Port Research
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• v.40 no.6
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• pp.385-390
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• 2016

ELoran Systems can provide Position, Navigation, and Time services with comparable performance to Global Positioning Systems (GPS) as a back up or alternative system. High timing and navigation performance can be achieved by eLoran signals because eLoran receivers use "all-in-view" reception. This incorporates Time of Arrival (TOA) signals from all stations in the service range because each eLoran station is synchronized to Coordinated Universal Time (UTC). Transmission station information and the differential Loran correction data are transmitted via an additional Loran Data Channel (LDC) on the transmitted eLoran signal such that eLoran provides improved Position Navigation and Timing (PNT) over legacy Loran. In this paper, we propose a technique for adapting the delay time compensation values in eLoran timing receivers to provide precise time comparison. For this purpose, we have designed a system that measures time delay from the crossing point of the third cycle extracted from the current transformer at the end point of the transmitter. The receiver delay was measured by connecting an active H-field, an E-field and a passive loop antenna to a commercial eLoran timing receiver. The common-view time transfer technique using the calibrated eLoran timing receiver improved the eLoran transfer time. A eLoran timing receiver calibrated by this method can be utilized in the field for precise time comparison as a GNSS backup.

• Journal of Positioning, Navigation, and Timing
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• v.11 no.1
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• pp.23-28
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• 2022

The eLoran system is a high-power terrestrial navigation system that is recognized as the most appropriate alternative to complement the GNSS's vulnerability to radio frequency interference. Accordingly, Korea has conducted eLoran technology development projects since 2016. The eLoran system developed in Korea provides 20 m positioning accuracy to maritime user in Incheon and Pyeongtaek harbor. To accurately calculate the position with the eLoran signal, it is necessary to apply a compensation method that mitigates the propagation delay. In this paper, we develop the compensation method to mitigate the eLoran signal propagation delay and evaluate the positioning performance in Incheon harbor. The propagation delay due to the terrain characteristics is pre-surveyed and stored in the user receiver. Real-time fluctuations in propagation delay compared to the pre-stored data are mitigated by the temporal correction generated at a nearby differential Loran station. Finally, two performance evaluation tests were performed to verify the positioning accuracy of the Korean eLoran system. The first test took place in December 2020 and the second in April 2021. As a result, the Korean eLoran service has been confirmed to provide 20 m location accuracy without GPS.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2017.11a
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• pp.97-99
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• 2017

본 논문에서는 eLoran 수신기 및 GPS 수신기를 통해 출력되는 NMEA 디지털 데이터를 이용해 GPS 값의 변화를 실시간으로 감시하고, GPS 위치정보의 이상 발생 시 eLoran의 위치정보로 자동 스위칭하여 재밍이나 스푸핑 등의 GPS 전파교란에 대비할 수 있는 장치의 개발에 관하여 연구하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.10a
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• pp.353-355
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• 2012

차세대 LF 송신기의 성능 및 구성요소 등을 확인하여, LORAN과 eLORAN 시스템 송신기로의 활용 여부와 이 송신기를 사용시 eLORAN 시스템에 미치는 영향 등을 다루고자 한다.

• Journal of Satellite, Information and Communications
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• v.2 no.2
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• pp.64-68
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• 2007

This paper describes the development of RF front.end equipment of a wide band high precision satellite navigation receiver to be able to receive the currently available GPS navigation signal and the GALILEO navigation signal to be developed in Europe in the near future. The wide band satellite navigation receiver with high precision performance is composed of L - band antenna, RF/IF converters for multi - band navigation signals, and high performance baseband processor. The L - band satellite navigation antenna is able to be received the signals in the range from 1.1 GHz to 1.6 GHz and from the navigation satellite positioned near the horizon. The navigation signal of GALILEO navigation satellite consists of L1, E5, and E6 band with signal bandwidth more than 20 MHz which is wider than GPS signal. Due to the wide band navigation signal, the IF frequency and signal processing speed should be increased. The RF/IF converter has been designed with the single stage downconversion structure, and the IF frequency of 140 MHz has been derived from considering the maximum signal bandwidth and the sampling frequency of 112 MHz to be used in ADC circuit. The final output of RF/IF converter is a digital IF signal which is generated from signal processing of the AD converter from the IF signal. The developed RF front - end has the C/N0 performance over 40dB - Hz for the - 130dBm input signal power and includes the automatic gain control circuits to provide the dynamic range over 40dB.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.641-642
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• 2012

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.11a
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• pp.145-148
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• 2023

초고속해상무선통신망의 다양한 수요처에 대응 가능한 무선설비 활용성 극대화를 위한 무선설비 시제품 개발과 관련하여 사용자의 요구사항 분석 및 e-Navi 표시장치 연계·검증 방안을 연구하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.128-129
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• 2013

e-Navigation의 도입에 따라, 선박 교통 정보의 대한 공유의 필요성이 높아지고 있다. 특히 선박 교통 관제 시스템인 VTS(Vessel Traffic Service) 시스템에서도 효율적인 관제와 e-Navigation에 도입에 따라 VTS 시스템간 데이터 공유가 필요한 실정이다. 이에 따라 국제항로표지협회(IALA, International Association of Marine Aids to Navigation and Lighthouse Authorities)에서는 VTS간 데이터 교환을 위한 표준 포맷인 IVEF(Inter VTS Exchange Format)을 제정하였다. IVEF는 XML 형태로 다양한 플랫폼에서 활용가능하다. 본 논문에서는 VTS 시스템 간 데이터 교환을 위한 표준 포맷인 IVEF를 이용하여 VTS 시스템 간 데이터 공유를 위한 웹 서비스에 대해 설계하고, 이를 응용하는 방법에 대해서 설명한다.