• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.5
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• pp.200-209
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• 2018

This study proposed a method to select existing facilities as a landmark in order to reset accumulated errors of dead reckoning in a tunnel difficult to receive GNSS signals in automated driving. First, related standards and regulations were reviewed in order to survey 'variety' on shapes and installation locations as a feature of facilities. Second, 'recognition' on facilities was examined using image and Lidar sensors. Last, 'regularity' in terms of installation locations and intervals was surveyed through related references. The results of this study selected a fire fighting box / lamp (50m), an evacuation corridor lamp (300m), a lane control system (500m), a maximum / minimum speed limit sign and a jet fan as a candidate landmark to reset positioning errors. Based on those facilities, it was determined that error correction was possible. The results of this study are expected to be used in repositioning of automated driving vehicles in a tunnel.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.4
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• pp.161-172
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• 2023

Autonomous driving vehicles recognize the surroundings through various sensors mounted on the vehicle and control the vehicle based on the collected information. The level of autonomous driving technology is improving due to the development of sensor technology and algorithms that process collected data, but the implementation of perfect autonomous driving technology has not been achieved. To overcome these limitations, through autonomous cooperative driving centered on infrastructure. In this study, developed a position correction sign that provides a reference for positioning of autonomous vehicles. First of all, an analysis was performed on the current status of positioning technology for autonomous driving. And measure the number of point clouds for the 1st sample consisting of two square reflective surfaces and 2nd sample that increased the vertical length of each reflective surface. Experimental results show that both primary and secondary products are installed at least 15 m apart It could be recognized as a sensor, and it was confirmed that the secondary production that increased the length of the top and bottom had a higher number of point clouds than the primary production and better expressed the shape of the facility.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.204-206
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• 2022

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 9^th 펄스 방식으로 변조될 수 있다. 본 논문에서는 eLoran 송신국에서 송출하는 LDC 메시지의 변조방법에 따른 수신 성능을 분석한다. 인천에서 운영 중인 eLoran 시험 송신국에서 9^th 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 분석한다. 또한 항로표지 관리선 인성 1호를 이용해 인천항 인근에서 실제 사용자의 LDC 메시지 수신률을 분석하였다. 본 연구결과는 eLoran 시범서비스 이후 본격적인 서비스 과정에서 중요하게 활용될 것으로 기대된다.

• Journal of Navigation and Port Research
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• v.46 no.6
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• pp.525-529
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• 2022

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.