• Water for future
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• v.55 no.6
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• pp.20-23
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• 2022

• 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.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.4
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• pp.337-345
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• 2007

National Geographic Information Institute has installed the first permanent Global Positioning System (GPS) station SUWN in 1995 and, as of today, the number of sites is 14. In this study, we visited all the 14 stations and determined if the site mount and antenna configuration conforms to the international site guidelines published by International GNSS Service and National Geodetic Survey. The environment around each station was also checked for the possibility of causing positioning errors. In addition, the GPS data quality was evaluated using the quality-checking program called TEQC. As a result of site visits, we found that low stations (TABK, CHJU, KWNJ, and WNJU) have unfavorable environment and TEQC results validated it. TEQC results also showed that the GPS receiver change during years 2005-2006 reduced the multipath errors and the number of cycle slips at every station.

• 한국공간정보시스템학회:학술대회논문집
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• 2005.05a
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• pp.53-58
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• 2005

21세기 지식정보화사회로 접어들어 GIS가 부각됨에 따라 GIS의 활성화를 위한 기본지리 정보에 대한 중요성이 대두되고 있다. 기본지리정보를 관리 감독하는 국토지리정보원에서는 2000년부터 기본지리정보구축에 관한 연구 등을 수행하여, 기본지리정보의 범위 선정과 데이터모델 표준화가 이루어 졌으며, 기본지리정보 유통과 구축에 필요한 생산사양이 이루어짐에 따라 기본지리정보의 품질 및 활용성에 대한 검토가 필요한 실정이다. 본 연구에서는 시설물분야 기본지리정보 생산사양에 따른 기본지리정보를 3단계에 걸쳐 구축하였으며 기 구축된 교통, 수자원, 행정경계 기본지리정보와 통합하여 활용성 평가를 수행하였다.

• Journal of Positioning, Navigation, and Timing
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• v.13 no.1
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• pp.103-110
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• 2024

In this paper, a test bed for real-time network Real-Time Kinematic (RTK) research was constructed using reference stations of the NGII. A group of candidate station networks was derived, including three stations in Seoul. The group consisted of four stations with a distance of less than 100 km between them. Among several candidates, a network composed of stations with short distances between them and demonstrating good data quality for all reference stations was selected as the test bed. After collecting real-time data in Radio Technical Committee for Maritime services (RTCM) format from the selected stations and conducting a noise analysis on measurements, mm-level carrier phase measurement noise was confirmed. Afterwards, the user set the reference station inside the test bed and analyzed the network RTK positioning performance of the MAC method using the GPS L1 frequency as post-processing. From the result of the analysis it was confirmed that the residual error for all users was within 10 cm after applying the correction. Additionally, after determining integer ambiguities through Least-squares AMBiguity Decorrelation Adjustment (LAMBDA), it was confirmed that the fix rate was 100%, and all ambiguities were resolved as true values.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.10a
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• pp.3-4
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• 2008

수치지도의 지리조사 기준은 80년대 후반 수치지도 전산화 작업이 국토지리정보원에서 시작되면서 건설부령으로 작성되어 몇 차례 수정이 되어 온 수치지도작성작업규칙과 내규에 의하여 작업되고 있다. 그러나 수치지도작성 작업지침은 수치지도 1.0을 기준으로 하고 있어 수치지도 2.0과 기본지리정보 등이 종이지도에서 수치지도 개념으로 제작환경변화가 발생하여 현재의 현지조사 기준에 문제점이 나타나고 있다. 따라서 본 연구에서는 이러한 수치지도의 지리조사 작업기준을 정립하기 위하여 작업규정, 속성자료, 관련자 설문 및 면담을 수행하여 문제점을 분석하였고. 적합한 수치지도 지리조사 작업기준을 제시하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.1415-1418
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• 2006

최근 정보 관련 산업 발달과 더불어 공간 정보의 중요성이 점점 강조되어, 국가 차원의 지리정보체계가 구현되고 있다. 국토지리정보원이 구축하고 있는 수치지도는 DXF로 제작되는데, 이 DXF맵은 GIS분야에서 필요한 속성정보나 위상정보를 갖지 못하여 지리정보 통합에 어려움이 있다. 지리정보의 여러 분야에 걸쳐 효율적인 데이터의 공유가 가능하도록 DXF파일에서 공간 개체를 추출하는 연구는 매우 중요하다. 본 논문에서는 DXF 파일에서 다양한 공간 개체를 추출하는 효율적인 공간 개체 추출기를 제안한다. 공간 개체 추출기는 DXF파일을 구성하는 요소들 중에 POLYLINE, POINT, CIRCLE, TEXT, ARC, LINE의 수치값을 비교하여 그에 해당하는 좌표값을 DAT 파일에 저장한다. 제안된 시스템은 웹상에서도 사용할 수 있다. 사용자는 단순히 웹서버에 DXF 파일을 업로드해서 공간 개체 추출기를 실행하여 결과를 다운로드 받아 활용할 수 있다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.2
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• pp.157-163
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• 2005

In the 21th century as knowledge-based society and according as GIS is embossed, demand of map is increasing rapidly for GIS's basic. Ministry of Construction & Transportation Republic of Korea National Geographic Information Institute who supervise basis geography information run the studies of basis geography information construction, therefore choice of each subject extent and standardization of data model for basis geography information is attained. In this study, framework data has been established in three steps according to Framework data Product Specification in Facility Area. Also the evaluation of usability was implemented as combining Framework data.

• Journal of Korean Society for Geospatial Information Science
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• v.14 no.2 s.36
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• pp.69-75
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• 2006

This study aims to standardize the work classification system in spatial data. It is the base frame to classify the general information systematically in spatial data construction process. Work process of the surveying firm and rules for basic surveying which is being accomplished in the NGII(National Geographic Information Institute) are investigated and analysed. Therefore, types, individual process, and results of surveying work is standardized. If the work classification system from this study is adopted as the national standard and is also advanced by construction methodology, the spatial data will be managed futuristically and systematically.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.2
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• pp.217-222
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• 2010

The geoid is the level surface that closely approximates mean sea level and usually used for the origin of vertical datum. For the computation of geoid, various sources of gravity measurements are used in South Korea and, as a consequence, the geoid models may show different results. however, a limited analysis has been performed due to a lack of controlled data, namely the GPS/Leveling data. Therefore, in this study, the gravimetric geoids are compared with the geodetic geoid which is obtained through the GPS/Leveling procedures. The gravimetric geoids are categorized into geoid from airborne gravimetry, geoid from the terrestrial gravimetry, NGII geoid(geoids published by National Geographic Information Institute) and NORI geoid(geoi published by National Oceanographic Research Institute), respectively. For the analysis, the geometric geoid is obtained at each unified national control point and the difference between geodetic and gravimetric geoid is computed. Also, the geoid height data is gridded on a regular $10{\times}10-km$ grid so that the FFT method can be applied to analyze the geoid height differences in frequency domain. The results show that no significant differences in standard deviation are observed when the geoids from the airborne and terrestrial gravimetry are compared with the geomertric geoid while relatively large difference are shown when NGII geoid and NORI geoid are compared with geometric geoid. Also, NGII geoid and NORI geoid are analyzed in frequency domain and the deviations occurs in long-wavelength domain.