• Korean Journal of Remote Sensing
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• v.18 no.6
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• pp.345-358
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• 2002

DGPS(Differential Global Positioning System) and RTK(Real time Kinematic) are in one of today's most widely used surveying techniques. However surveying with these techniques is restricted by the distance between reference and rover station, and it is difficult to process data in realtime by their own organizational limitation in precise measurement of positioning. To meet these new demands, in this paper, new DGPS and RTK correction data services through the Internet and PSTN(Public Switched Telephony Network) have been proposed. For this purpose, a DGPS and RTK error correction data transmission system is implemented for long-distance using the Internet and PSTN which allows a mobile user at which the rover receiver is located to receive the correction data from the reference in realtime, and analyzed and compared with DGPS and RTK performances by experiments through the Internet and PSTN for the distance and the time.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.4
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• pp.824-830
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• 2010

In order to prepare for increasing performance requirement for Differential Global Navigation Satellite System (DGNSS) services of International Maritime Organization (IMO) and International Association of Lighthouse Authorities (IALA), this paper focuses on design of network-based Automatic Identification System (AIS) reference station system that can perform the functionality of Differential Global Positioning System (DGPS) reference station in an AIS base station system. AIS base station receives the differential corrections from the DGPS reference station, and it is not a method for transmitting the received differential corrections to onboard AIS units, but it is a method for generating the optimized differential corrections for onboard AIS units in AIS coverage. Therefore this paper proposes an algorithm for generating the differential corrections at AIS reference station, and performs the performance assessment of the proposed algorithm based on DGPS correction data measured from a DGPS reference station. Finally this paper discusses the test results and efficiency of the proposed system.

• Journal of Positioning, Navigation, and Timing
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• v.3 no.1
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• pp.25-30
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• 2014

Differential Global Positioning System-Correction Projection (DGPS-CP) algorithm, which has been suggested as a method of correcting pre-calculated position error by projecting range-domain correction to positional domain, is a method to improve the accuracy performance of a low price GPS receiver to 1 to 3 m, which is equivalent to that of DGPS, just by using a software program without changing the hardware. However, when DGPS-CP algorithm is actually realized, the error is not completely eliminated in a case where a reference station does not provide correction of some satellites among the visible satellites used in user positioning. In this study, the problem of decreased performance due to the difference in visible satellites between a user and a reference station was solved by applying the Multifunctional Transport Satellites (MTSAT) based Augmentation System (MASA) correction to DGPS-CP, instead of local DGPS correction, by using the Satellite Based Augmentation System (SBAS) operated in Japan. The experimental results showed that the accuracy was improved by 25 cm in the horizontal root mean square (RMS) and by 20 cm in the vertical RMS in comparison to that of the conventional DGPS-CP.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.15 no.2
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• pp.1-8
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• 2007

In this research, algorithm and software for the medium frequency signal analysis of DGPS(Differential Global Positioning System) station were developed. Based on new MF(Medium Frequency) algorithm, the software of NDGPS(National DGPS) signal analysis was developed for coverage analysis. Predicted MF propagation data from this software was compared to the measurement data for the verification of a developed MF algorithm. GIS(Geographic Information System) techniques including digital map with elevation data were used because MF propagation is closely related to ground conductivity, mountains, building intensity.

• Journal of Positioning, Navigation, and Timing
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• v.5 no.1
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• pp.21-28
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• 2016

The Wide Area Differential Global Positioning System (WADGPS) that uses a number of Global Navigation Satellite System (GNSS) reference stations are implemented with various types and provide services as it can service a wide range of areas relatively. This paper discusses a constellation design of reference stations and performance analysis of the WADGPS. It presented performance results of static and dynamic users when wide area correction algorithm was applied using eight reference stations.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1998.11a
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• pp.248-251
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• 1998

본 연구에서는, GPS 기준점(Optimal reference point)을 기준으로 한 DGPS(Differential Global Positioning System)와, 준 기준점(Sut-optimal reference point)을 기준으로 한 DGPS 시스템을 구현하였다. 이러한 2가지 DGPS 시스템으로부터 얻은 위치를 분석 평가하고, 그 결과를 나타냈다. 실험 결과, 준기준점을 기준으로 하는 DGPS 시스템은, 기존의 DGPS 기준국을 사용하지 않더라도 정밀 위치 측정이 가능함을 나타내었다.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1618-1622
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• 2004

In this paper, the linearly interpolated PRC(Pseudo Range Correction) regenerating algorithm was applied to improve the DGPS(Differential Global Positioning System) positioning accuracy at user's spot by using the various PRC information obtained from multi-DGPS reference stations. The PRC information of each GPS satellite is not varying rapidly; it is possible to assume that the variation of PRC information of each GPS satellite is linear. So the linearly interpolated PRC regenerating algorithm can be applied to improve the DGPS positioning accuracy at user's spot by using the various PRC information obtained from multi-DGPS reference stations. To test the performance of the linearly interpolated PRC regenerating algorithm, maritime DGPS reference stations' PRC data was used in RTCM format. 11 maritime DGPS reference stations are in service providing DGPS information to public since 1999. Two set of 3 DGPS reference stations are selected to compare the performance of the linearly interpolated PRC regenerating algorithm. The DGPS positioning accuracy was dramatically improved about 40%. Linearly interpolated PRC regenerating algorithm adopted multi-channel DGPS receiver will be developed in near future.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.291-291
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• 2002

DGPS(Differential Global Positioning System) and RTK(RealTime Kinematic) is in one of today's most widely used surveying techniques. But It's use is restricted by the distance between reference station and rover station and it is difficult to process data in realtime by it's own orgnizational limitation in precise measurement of positioning. To meet these new demands, In This paper, new DGPS and RTK correction data services through Internet and PSTN(Public Switched Telephony Network) have been proposed. For this purpose, we implemented performance a DGPS and RTK error correction data transmission system for long-distance using the internet and PSTN network which allows a mobile user to increase the distance at which the rover receiver is located from the reference in realtime. and we analyzed and compared DGPS and RTK performance by experiments through the Internet and PSTN network with the distance and the time.

• 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.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2007.12a
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• pp.98-99
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• 2007

It is necessary to use satellite radio navigation system as well as satellite radio navigation augmentation system such as differential Global Positioning System to achieve the positioning accuracy and reliability requested by International Maritime Organization in port and coastal area. Especially, position accuracy of DGPS user is effected by accuracy of pseudorange correction broadcasted from DGPS reference station. This paper shows pseudorange correction calculation algorithm adopting a non-common error estimation filter in order to improve accuracy of pseudorange correction. Finally, this paper verifies that the pseudorange correction calculated by adopting a non-common error estimation filter satisfies performance specifications of RTCM.