• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.231-235
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• 2003

실시간 동적 GPS 측위를 이용한 해저수심측량은 GPS 수신기가 이동중인 상태에서 신호단절 없이 연속적인 수심측정이 가능하며 등수심도와 등고선 제작에 정확한 위치를 결정할 수 있고, 음향측심기는 발사파와 수신파의 도달시간을 측정하여 수심을 관측할 수 있기 때문에 실시간으로 정확한 3차원 측량이 가능하다. 본 논문에서는 해안지역에 대한 지형 분석을 하기 위하여 기준점에 대한 정지관측을 실시하여 좌표변환계수를 산출하고, 이로부터 실시간 동적 GPS 측량과 음향측심기를 이용하여 해운대 해수욕장과 해안을 관측하였다. 1:1,200 축척의 수치지도에서 추출한 수치표고모델에서의 체적은 97953.9 ㎥이며, 실시간 동적 GPS와 음향측심기를 이용하여 추출한 수치표고모델에서의 체적은 95994.9 ㎥로 나타났다. 이는 수치지도에서의 체적과 측량결과의 체적이 단지 2.0%정도로 나타나 실시간 동적 GPS와 음향측심기의 결합에 의한 해저수심측량이 매우 성공적임을 알 수 있었다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.1
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• pp.73-80
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• 2004

The purpose of this study is the GCP/DEM estimations through satellite stereo image interpretation using GPS. We carried out GPS observation fixing first order control points and GPS permanent stations. Comparing static surveying and kinematic surveying, we analysed the surveying methods for GCP and DEM estimations. As the results, considering SPOT image spatial resolution, the DEM can be made through satellite stereo image interpretation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.2
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• pp.139-147
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• 2008

The positioning accuracies tend to deteriorate as the distance between the rover and the reference station increases in the Real-Time Kinematic (RTK) surveys using Global Positioning System (GPS). To solve this problem, the National Geographic Information Institute (NGII) of Korea has installed Virtual Reference System (VRS), which is one of the network-based RTK systems. In this study, we conducted the accuracy tests of the VRS-RTK surveys. We surveyed 50 control points inside the NGII's GPS Continuously Operating Reference Stations (CORS) network using the VRS-RTK system, and compared the results with the published coordinates to verify the positioning accuracies. We also conducted the general RTK surveys at the same control points. The results showed that the positioning accuracy of the VRS-RTK was comparable to that of the general RTK, because the horizontal positioning accuracy was 3.1 cm while that of general RTK was 2.0 cm. Also the vertical positioning accuracy of VRS-RTK was 6.8 cm.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.87-90
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• 2003

정밀한 위치결정에 사용되는 GPS는 초기 군사목적을 벗어나 자동차, 선박, 비행기 등의 항법은 물론 측량분야, 지각 및 구조물의 변위 감시, 우주, 통신, 국방 분야 등 매우 광범위한 분야에서 활용되고 있으며, 그 이용도가 급속히 증가하는 추세이다. 그러나 GPS 관측값은 부정오차와 정오차 등 많은 오차를 포함하고 있기 때문에 이를 소거하거나 최소화하여야 한다. GPS 오차는 크게 위성궤도나 위성시간 오차등 위성에 관련된 오차, 수신기 잡음이나 다중경로 등 수신기 관련 오차, 그리고 대류권이나 전리층에 의한 전파 오차로 구분할 수 있다. 이들 오차들은 대부분 차분방법과 수학적 알고리즘에 의해 소거되거나 최소화되지만, 다중경로와 수신기 잡음은 소거하거나 축소할 수 없다. 다중경로는 관측당시의 수신기 주변환경에 따라 바뀌기 때문에 수학적으로 소거할 수 없으며, 수신기 잡음은 수신기 내부의 노이즈로 인하여 발생하기 때문에 소거하기가 상당히 어렵다. 본 연구에서는 다중경로에 의한 GPS 기선변화를 알아보기 위해서 여러 조건하에서 정적 GPS 측량을 실시하였다. 먼저 정확한 좌표를 알고 있는 한 점에 GPS를 설치하고 다른 두 대의 GPS을 임의 점에 설치하였고, 이들 두 GPS 중에 하나의 수신기에 다중경로 환경을 설정하였다 정적 GPS 관측시 기선에 어떠한 변화가 오는 파악하기 위해서 기선처리와 망조정을 통해 기선길이와 좌표값을 산출하였다. 이러한 다중경로 실험은 구조물 모니터링 등 mm 정확도를 요구하는 GPS 측량에 유용하게 사용될 수 있을 것이다.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2002.10a
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• pp.63-66
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• 2002

• 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.

• Journal of Cadastre & Land InformatiX
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• v.47 no.1
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• pp.95-110
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• 2017

The network RTK surveying has been widely used in the field of cadastral surveys in recent years, and its use is gradually expanding. As a result of the implementation of GPS static surveys by civilian companies in accordance with the progress of the cadastral surveys and gradual civilian transfer plans and cadastral surveys, there has been an increase in the number of civilian companies performing surveys. In this paper, we describe the process of applying the results of analysis of conformity using the network RTK site calibration function on the local coordinate system to the GPS static surveying of the cadastral reference points in Anyang city. In addition, the measurement results of the network RTK site calibration function and the results of the GPS static surveying network reconciliation in the local coordinate system were compared, and the performance was determined within 0.04m maximum of RMSE(Root Mean Square Error), and further study on the application method is needed.

• 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.

• Spatial Information Research
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• v.9 no.2
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• pp.309-324
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• 2001

To apply the real-time kinematic GPS surveying technique, this research has tried to obtain the TOKYO datum first from the continuous reference stations distributed all over the country. Then, analysis of the geography of a coastal area including both of land and sea has been carried out by the post-processed continuous kinematic GPS technique and the real-time kinematic GPS surveying technique. After considering the initial conditions and measuring time zone for real-time kinematic GPS, post-processed and the real-time kinematic GPS measurements have been carried out. A new system has been proposed to store measured data by using a program developed to store GPS data in real time and to monitor the satellite condition through controller simultaneously. The accuracy of GPS data acquired in real time was as good as that acquired by post processing. It is expected that it will be useful for the analysis of coastal geographic characteristics because DTM can be also constructed for the harbor reclamation, the dredging and the variation of soil movement in a river.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2009.04a
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• pp.157-162
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• 2009

Korea established a King Sejong Station in King George Island in 1988. With the establishment of a station, various researches such as geology, biology, geophysics and meteorites have been conducted. Surveying and mapping has been performed since 1990, however, the results had a large errors due to old GPS instrument and autonomous positioning with SA. In this study new GPS surveying was tried using a state-of-the-art GPS instrument and relative positioning.