• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.4
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• pp.54-63
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• 2013

In this paper, we evaluate the accuracy of the vertical positioning by distance using Network RTK-GPS. The experimental results confirm that Network RTK-GPS method can acquire data quickly and accurately than conventional leveling methods so that the Network RTK-GPS method is a relatively efficient and economical way for the vertical positioning. Results of validation using permanent GPS stations indicate that visible satellites, PDOP, and VDOP are very good for the vertical positioning. Integrated reference points such as U0997 and U0921 are satisfied with 3 ratings in the rules of public leveling and all the rest are proved improper. When the vertical positioning using Network RTK-GPS is implemented, the geoid height of EGM2008 should be applied for leveling. If the number of geodetic satellite are increasing in the near future, the vertical positioning using Network RTK-GPS can be possible in all the range.

• Journal of Korean Society for Geospatial Information Science
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• v.10 no.2 s.20
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• pp.87-95
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• 2002

Real-time Kinematic GPS enables high accuracy Positioning by real time. If ambiguity use an integer solution, can obtain accuracy of several 'mm', and can obtain accuracy of tens 'em' if use real solution. In this study, We accomplish surveying by existent traditional surveying techniques (Total Station), Static GPS techniques and RTK-GPS techniques by Field Calibration about uniformity measuring point and then compared and ana1yzed each techniques positioning accuracy etc.. Result that achieve by Static-GPS in Plane area, about all measuring points, expressed error fewer than 3cm. Result that achieve RTK-GPS Surveying by Field Calibration in Plane area, could know that RTK-GPS techniques by Field Calibration is available in Plane area because expressing errors fewer than all 6cm, except case that do not get fixed solution of ambiguity Field Calibration RTK-GPS could know economically than existent conventional type measurement and existent GPS's measurement techniques that efficiency is very high.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.04a
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• pp.119-122
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• 2003

• Journal of the Korean Geophysical Society
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• v.9 no.2
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• pp.77-86
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• 2006

Aplications of the real-time kinematic GPS surveying and inertial measurement unit have been beingRTK GPS allows the use of a static base station and remote rover unit to allow for data collectionwithin several seconds and in real time. It is useful for monitoring the behaviors of massive structureslike bridges. And this study purposed to implement a method of deciding the acurate dynaimc attitudeof structures by IMU. In this study, among GPS methods, we used RTK GPS to analyze the precisionof monitoring and then on the basis of it, we developed a monitoring system using RTK GPS anda deviation betwen observation values, X axis was 1mm, Y axis was 1mm and Z axis 2.2mm. I tturned out that it was possible to monitor and measure structures by RTK GPS and IMU.

• Journal of Korean Society for Geospatial Information Science
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• v.23 no.3
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• pp.31-39
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• 2015

This paper presents the static and kinematic positioning accuracy by the real-time GPS positioning modes of the low-cost GPS receivers using NTRIP-based augmentation service. For this, acquires both the raw measurements data of the field tests by LEA 6T GPS module of u-blox AG, and correction communication via NTRIP caster with RTKLIB as an open source program for GNSS solution. With computing the positions of the check points and road tracks by six kinds of GPS positioning modes which are Single, SBAS, DGPS, PPP, RTK, and TCP/IP_RTK, compared these results to the reference position of the check points. The position error average and rmse of the static test by GPS L1 RTK surveying showed $N=0.002m{\pm}0.001m$, $E=0.004m{\pm}0.001m$ in horizontal plane, and $h=-0.116m{\pm}0.003m$ in vertical, these results are very closed to the coordinates with the geodetic receiver. Especially, in case of the kinematic test with obstacles located on both sides of road, the computed track with ambiguity fixing showed very similar trajectory considerably from VRS network RTK mode. And also, evaluate and verify the performance of the TCP/IP_RTK mode developed based on TCP/IP protocol.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.4
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• pp.415-421
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• 2002

A recently lot of facilities have been constructed from rapidly development of science and economic growth. Among them, bridges are tending to be large because of geometrical problems of the road. And then the method of satellite surveying is being practical use variously out of present surveying methods. Therefore in this study it takes a measurement of bridge displacement using the RTK GPS Mode instead of the using mechanical measurement system. The observation value was verified by using Total Station to inspect observation value of RTK GPS. And then, by using the Delphi of object intending language, developed bridge warning system and applied it. The result of this study was found verification error of 0.2~8.3mm, therefore the measurement of bridge displacement of grand bridge can be applied by using An GPS.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.04a
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• pp.65-69
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• 2004

기존 라디오파를 이용한 RTCM 방식에서는 전파의 직진성으로 인한 수신 장애가 많이 발생하였다. 이런 문제를 극복하기 위해 라디오 모뎀을 사용하지 않고 휴대폰에 내장된 CDMA 방식을 이용하여 이동전화국 기지국을 통한 오차 보정량을 전송하여 RTK-GPS의 문제점을 해결하고자 하였다. 연구 결과 기존 RTCM 방식과 같은 건물 차폐에 따른 신호 차단의 영향은 없었으며, 제적 작업 시에도 라디오 모뎀의 송수신의 장애로 인한 데이터 손실을 막을 수가 있었다. 마지막으로 10km이상의 거리에서도 작업을 수행하였다. 그 결과 이동전화국 기지국을 이용하였기 때문에 신호의 송수신에는 문제가 없었지만, 공간적 상관성의 문제로 인해 그 값을 쓸 수가 없었다. 따라서, 최근 증가하고 있는 GPS 측량 기법 중에서 현장에서 손쉽게 성과 값을 구하는 실시간 이동측량(RTK GPS Real Time Kinematic GPS)의 문제점을 보완하고 그 효율성을 제고하였다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.4
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• pp.277-283
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• 2013

GPS RTK surveying has an issue that the positioning error increases as the base line distance between the reference station and rover station increases. However, nowadays, an accuracy assessment that can handle such issue is surely required because of the modernization of GLONASS, Galileo project, and other improvements of satellite receiving conditions. Therefore, in this research, we compared and analyzed data sets collected with the CORS network, placed at NGII and NDGPS, using Internet RTK surveying in different satellite receiving conditions. As a result, there was a negative effect on the positioning accuracy as the base line distance increases. Furthermore, we could collect quantitative data of the accuracy of RTK surveying. When national-wide GNSS system is fully established, this result will contribute the growth of various GNSS industries including survey industries and land survey industries.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.16 no.2
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• pp.271-279
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• 1998

This paper discusses the development of compaction management system using Real Time Kinematic (RTK) GPS technology for the efficient management or compaction. The use or RTK provides the land surveyors with a graphical display of his/her corrected position on the ground at that moment in time. In this work, we intended to improve the efficiency of compaction management showing the route of rollers and the total number of compaction obtained from management software (GPSROLL v.1.0) developed in this study. The RTK GPS system installed on the roller. To improve the efficiency of field management, GPSROLL software provides also data processing module for the field soil test and the field surveying data. GPSROLL system is based on the Korean GUI for user-friendly data input and output.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.4
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• pp.393-401
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• 2003

Automatic control technologies for the marine pile driving provides accurate and rapid intruding into the planned positions of the pile with planned slope and direction, so that the construction maintenance and management are more efficient and the quality of the construction is more promising. Therefore, in this study, the application scheme of RTK GPS to the automatic control of the pile driving presented. It is expected that the presented scheme using the precise RTK GPS technique assures the efficient and economic 3D positioning accuracy for the precise marine construction management like the precise foundation of marine structures made of piles and the dredging work. It is found that the suggested scheme decrease 60% of the construction error compared with specifications reference because marine position accuracy is measured within 4cm in real time. In addition, the automatic position control system using GPS reduced the construction period and cost compared with existing methods about 30% and 35%, respectively.