• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.06a
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• pp.63-64
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• 2009

본 논문에서는 DGNSS의 현대화에 대비하고 국제적으로 논의되고 있는 소프트웨어 기반 RSIM 시스템의 기능구현을 위하여, 해양용 DGPS 기준국의 무결성 감시 기능을 설계한다. 무결성 감시국(IM)의 핵심 기능은 기준국 시스템 이상에 따른 알람정보의 생성과 피드백 메시지를 기준국(RS)으로 전송하는 것이다. 이러한 기능의 설계 및 실험적 차원의 성능검증을 위하여, 먼저 소프트웨어 RSIM의 아키텍처에 대해 살펴보고, 다음으로 RTCM SC-104 RSIM의 해양용 DGPS 기준국 무결성 감시를 위한 성능표준에 대하여 분석한다. 그리고 DGPS 기준국의 무결성 감시국 기능을 설계하고, 무결성 정보 생성 및 처리과정을 제시한다. 마지막으로 시뮬레이션을 통한 성능분석과 시스템 구현을 위한 향후 연구방향에 대해 논의한다.

• The KIPS Transactions:PartA
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• v.13A no.4 s.101
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• pp.335-342
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• 2006

As PRC linear interpolation algorithm is applied after analysed and verified in this paper, the unknown location of a user can be identified by using PRC information of multi-DGPS reference station. The PRC information of each GPS satellite is not varying rapidly, which makes it possible to assume that PRC information of each GPS satellite varies linearly. So, the PRC regeneration algorithm with linear interpolation can be applied to improve the accuracy of finding a user's location by using the various PRC information obtained from multi-DGPS reference station. The desirable PRC is made by the linear combination with the known position of multi-DGPS reference station and PRC values of a satellite using signals from multi-DGPS reference station. The RTK-GPS result was used as the reference. To test the performance of the linearly interpolated PRC regeneration algorithm, multi-channel DGPS beacon receiver was built to get a user's position more exactly by using PRC data of maritime DGPS reference station in RTCM format. At the end of this paper, the result of the quantitative analysis of the developed navigation algorithm performance is presented.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.10b
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• pp.23-28
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• 2000

The DGPS is used to improve the accuracy of the GPS by determining the positioning error data known locatio and subsequently transmitting the determined error, or corrective factors, to users of the GPS operating in the same geographical area. The accuracy of the DGPS available to real0time users is published in the Federal Radio-Navigation Plan to be better than 10 meters, although users often experience accuracies of better than 3 meters. USA recently decided to expand the marine DGPS service for land applications and initiated the Nationwide DGPS chain. Korea is processing for improving the marine DGPS. We have not achieved Full Operational Capability. But after announcing FOC, we have to begin expansion of DGPS into land. This paper investigate the availability of marine DGPS in land. The results will provide a basic guide for estimation of a propagation loss of the marine DGPS frequency in land.

• Journal of Navigation and Port Research
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• v.33 no.6
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• pp.395-400
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• 2009

In order to prepare for the DGNSS recapitalization and implementation of the functions for software based reference station and integrity monitor (RSIM) system, this paper proposes a design of integrity monitor functions of maritime differential GPS RSIM. The most critical functions of the integrity monitor (IM) are to generate and send flags to the reference station (RS) along with system feedback. Firstly, it presents the architecture of software based RSIM, and analyzes the performance standard of integrity monitor for maritime DGPS reference station This paper then designs the functions of integrity monitor for DGPS reference station based on the performance standard. Finally, this paper presents the results of performance analysis for the functionality of integrity monitor using the GNSS simulator. it discusses the study method and its application for the system implementation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.732-736
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• 2001

DGPS는 미 군사용 신호를 이용한 정밀도 수준을 제공할 수 있는 위성항법 시스템으로써 30여개 국가에서 해양용 국가망 위주로 구축되고 있다. 특히 미국은 해양용 DGPS 국가망을 내륙으로 확장한 NDGPS(Nationwide DGPS)체계 구축을 2002년까지 완성할 예정이다. 우리나라도 해양용 국가망을 운영하여 해양활동을 하는 사용자에게 3차원 고정밀 위치정보를 제공하고 있다. 근래에 우리나라 연안에 구축되어 사용중인 해양용 라디오비이콘형 DGPS망을 육상으로 연계한 서비스범위 확대방안이 논의되고 있다. 본 연구는 NDGPS에 대한 기초연구로서 운용중인 DGPS 기준국신호를 모델로 하여 해상 전파 설계치 대비 거리 및 지형변화에 따른 전계강도 변화를 분석하였다.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.4
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• pp.491-499
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• 2011

Starting with maritime DGPS base stations of Palmido, Ochongdo which have been operated since 1999, truly our nation has become the most powerful country possessed with total of 17 DGNSS base stations in the field of DGNSS operation infrastructure. This paper examines into the country's DGNSS services as measuring the service range of the maritime DGPS base stations in the domestic ferry lines which sections are from Jeju to Incheon, from Busan to Jeju, from Jeju to Nokdong, the propagation characteristics of the radio waves of 300 kHz bands on sea and land path. As a result of identifying the service range of the DGPS in the sea routes of the southern sea and the western sea, the measured results of the DGPS signals are confirmed more than 100 NM(recommended service range). It can be possible to practical use the position information, which is safe navigation and various marine traffic management systems. It will be useful an expansion of maritime DGPS reference station in the near future.

• Journal of Navigation and Port Research
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• v.26 no.1
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• pp.15-21
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• 2002

Re Ministry of Maritime Affairs and Fisheries in Korea completed the installation of 8 maritime DGPS station mfd is to going install 3 additional Maritime DGPS station for the enhancement of dual coverage in Korean coasts until Oct. 2002. Moreover, Korean government decided to provide the NDGPS service over the whole Korean inland area, which will be schedule to complete until June. 2004. On this paper to evaluate the propagation characteristics of using maritime DGPS site as un element of NDGPS ann to evaluate the required number of additional NDGPS sites, the propagation characteristics of the radio waves of 300kHz bands on sea and land nth are studied With the result of study, the conceptional design of Korean NDGPS System is proposed, which consists of 5 NDGPS sites with modified antenna and tかee coverage monitoring sites.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.3
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• pp.181-189
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• 2001

This paper describes the positioning accuracy of GPS moduls (KGP9800C, KiRyung) which need to record the operating position of fishing boat as realtime processing in order to develope auto recording system of fishing boat's operating information, and then it's positioning accuracy for DGPS receiver (MGP-100D, Shin-A) and DGPS beacon (GP-36, Furuno) were analyzed. Futhermore, it was examined the positioning error of the GPS module with processing algorithm to minimize the effect of the signal fluctuations. The results indicate that the positioning error is able to decrease 5m as 2drms, and such improvement of positioning performance for GPS module (KGP9800C) can be provide the basic design data in the development of the auto recording system of fishing boat's operating information.

• Journal of the Korean Geophysical Society
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• v.9 no.4
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• pp.387-395
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• 2006

Nowadays, various digital maps on a reduced scale were drawn in Korea including the topographic series of a nation. Though these digital maps are drawn and revised by using aerial photograph or satellite image, there are some problems that it is difficult to revise or renew the topography and natural feature immediately which changes frequently. As the countermeasures of these problems we use GPS accumbency method, which provides user with convenience and accumbency accuracy which is required to revise and renew digital maps. But acquiring correct position by using GPS only may cause not a few errors because of environmental effect of satellite signal errors that GPS obtains. Although accumulated errors which is the major problem of existing method was diminished owing to the position signal received from satellite which is about 20,183km above, the area that can not receives the signal is occur such as woods and high-rise buildings space. And because of the GDOP (Geometry Dilution of Precision) of GPS satellite and the periodically changing orbit of the satellite, the position calculating problems occur. For settlement of these problems and accurate position determination, DGPS (Differential GPS) is indispensably needed. So, in this study, by adapting Radio Beacon Receiver for marine position determination which is the most convenience method of DGPS methods, we elevated accuracy of modification and renewal of digital map and, having wide application in various measurements, proposed the rapid measurement method about widespread area. In this study, wewant to propose the work scheme of rapid modification and renewal of digital map by using Beacon GPS which is comparatively cheap of all the DGPS methods and which makes it possible to measure independently.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.3
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• pp.181-189
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• 2002

This paper describes the positioning accuracies for single and multiple reference stations at fixed stations in Yosu harbor and Pukyong National University in the south coast of Korea from Jan. to Oct. 2001. Also we observed the change of positioning accuracy during a day and the available range of the DGPS reference station. he results obtained are main summarized as follows; 1. With single DGPS reference station, 2drms and the average positioning .error were 5.6m, 7.3m respectively. Measurement positions indicated an incline toward one way away from the actual position. 2. With multiple DGPS reference stations, 2drms and the average position error were 5.5m, 3.2m for the arithmetic mean, respectively. They were 5.3m, 3.8m for the weighted average, respectively. As far as the separation between the user and the reference station, using multiple reference stations improved position accuracy more than using single reference station. 3. The average positioning error increased between 16: 00 and 22 : 00. The average number of observed satellite and HDOP were 7.1m, 0.49 respectively. 4. Coverage of DGPS reference stations in the south coast of Korea was estimated to be 110nm. Signal strength and signal to noise ratio was not available the DGPS signal below 19㏈, 8㏈ respectively.