• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.6
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• pp.591-598
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• 2017

This study is for coordinates analysis(geocentric and rectangular coordinate) of Korean geodetic VLBI which has been operated by NGII (National Geographic Information Institute) in Republic of Korea since 2014. The purpose of this study is a fundamental research to determine the Korean geodetic datum. The VLBI data recorded from September 29th 2014 to July 31th 2017, total approximately a hundred of VLBI databases, is used to calculate daily positions and position rates. The VLBI coordinates are based on ITRF(2000,2005,2008,2014) with epochs of the first Korean VLBI observation date(September 29th 2014) and Korean Geodetic Datum(January 1st 2002). And as a results of VLBI observation, Korean VLBI coordinate movement velocity of 3.1cm/yr in the direction of $112.4^{\circ}$.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.04a
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• pp.3-8
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• 2003

우리 나라에서도 세계적 추세에 따라 세계공통으로 사용되는 $\ulcorner$세계측지계$\lrcorner$ 에 의거한 신국가기준좌표계를 결정하고, 대한민국경위도원점을 고정도로 유지 관리하기 위해 국립 지리원이 주관해서 측지 VLBI 사업을 추진하고 있다. 국내에서는 처음으로 추진되는 측지 VLBI 사업이기 때문에 사업을 성공적으로 수행하기 위해서는 면밀한 사전조사 연구와 추진전략이 필요하다. 본 논문에서는 이러한 국가측지 VLBI 사업을 효율적으로 수행하기 위한 추진전략에 대해서 논하였다.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.3
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• pp.79-85
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• 2008

This study aims to derive a practical coordinate transformation method for the existing geographic information database. After analyzing the status and problems of existing 1/1,000 digital base map and GIS application database, the transformation parameters are estimated and the accuracy of the transformation is determined based on the transformed coordinates. We analyzed the accuracy of a transformation using the published national transformation coefficients as well as the estimated local transformation coefficients using national and urban control points in a study area. In addition, the 1/1,000 digital base map from aerial triangulation is compared with respect to the coordinates of urban control points. Based on the comparison, the biases on the national control points which were used at the time of digital map generation was analyzed. Then, the accuracy of transformed coordinates based on the world geodetic system using local transformation coefficients estimated from urban control points are determined. We also analyzed the transformation accuracy of underground infrastructure database using the same transformation method as the case of 1/1,000 digital base map. Through this study, it was found that the estimation of transformation coefficients by Molodensky-Badekas using urban control points was suitable for a local government. Furthermore, it was obvious that the accuracy of a 2-dimensional affine transformation was comparable to that of 7 parameter transformation for a local area. Applying the coordinate transformation and bias correction, we could transform GIS application database which was built by an offset surveying based on digital base map within the transformation accuracy of 10 cm. Therefore, it was judged that there will not be a big problem on the transformation of the GIS DB to the world geodetic system.

• Journal of Cadastre & Land InformatiX
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• v.54 no.1
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• pp.103-115
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• 2024

Trilateral adjustment can complement the problem of transforming cadastral maps into World Geodetic Coordinate system. First, it is possible to determine adjusted coordinate of common points that match each other over a wide area. Second, calculations that focus on specific points can be performed. Third, a solution that maintains the shape of the regional network can be obtained through constraints. Thus, the point coordinates can be determined appropriately for the survey system. In addition, heterogeneous survey results that span regions with different coordinate origins can be calculated on a single origin coordinate. This improves the efficiency of the workflow in tranforming cadastral maps into World Geodetic Coordinate System.

• Spatial Information Research
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• v.22 no.1
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• pp.35-43
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• 2014

The Triangle Mesh Warping method is suggested and applied in coordinate transformation to world geodetic system in this study. The common points of Uiwang city are used to compare the transformation accuracy of the suggested methods with existing national coordinate transformation methods. As a result, the Triangle Mesh Warping method was satisfied with accuracy criteria for positioning on a map larger than scale 1/1,000 with smaller number of common points and without distortion modeling. Additionally, in case of Guri and Pyeongtaek city that established the World Geodetic System, the suggested method generates the result of transformation accuracy better than 5cm. Based on the test, it was found that the suggested method improves the problem of securing many common points and reduces the problem of mis-match between the transformed data of adjacent areas. Accordingly, for transformation of large-scale topographic map, cadastral map, GIS DB and serial cadastral map to the World Geodetic System, it is judged that the Triangle Mesh Warping would be a good method for economical efficiency and accuracy using by minimum common point.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.6
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• pp.631-639
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• 2011

There are problems in using existing fisheries maps, because of deterioration of paper maps, as well as various coordinate systems. In this study, accuracy of fishery maps in World Geodetic System are evaluated. Materials on fishery rights in the Jeollanam-do Province, a study area, used many kind of coordinate systems. During digitization, these coordinate systems have been converted and unified in one World Geodetic System, and one projection origin. In this research, the accuracy of the products of digitization is verified using DGPS surveying. The RMSEs are minimum of 4.62m(at the Younggwang Seas) to maximum of 17.47m(at the Jangheung Seas), and average of 11.97m. The results shows that the digitized fishery maps meet the accuracy standard of 1/25,000 digital topographic maps.

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.4
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• pp.15-23
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• 2017

The WGS conversion project of cadastral drawing (promoted by the Ministry of Land) is not able to reflect the cadastral registration due to subtle differences such as area and location. When converting the digital cadastral region to the world geodetic system, the boundary point coordinates must be changed to the legal coordinate units. However, there is a phenomenon that occurs in which the minute area changes do not coincide with the area registered in the cadastral registration when the coordinate unit is changed. In this study, we have developed a method to adjust many parcels collectively by applying a passive fine-tuning method used in cadastral resurvey project to solve these problems. Total 1, total 2+1, interval 1, interval 2+1, etc. were classified based on the number of parcels that need to be considered for the range of adjustment and the area condition. The analysis of the experimental area (after developing SW for comparison of each method) showed that the total 2+1 method is suitable for the location accuracy and the interval 2+1 method is suitable for the temporal efficiency.

• Journal of Cadastre & Land InformatiX
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• v.44 no.2
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• pp.139-153
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• 2014

The world geodetic system transformation of cadastral record have to minimize differences of boundary and area being in cadastral record according to transformation for that is direct connected with the land owner and property protection. However it is very difficult to accurately maintain the before and after transformation because coordinate transformation is generally using a mathematical conversion formula. At present, Helmert model by using 4-parameter is official coordinate transformation model for Cadastral Resurvey Project but scale factor is most sensitive to changes of area and relative position in the same parcel. In this study, it was proposed 3-parameter method using by scale factor fixing through the application of a Helmert in order to avoid changing the area difference and keeping the error within the tolerance range of the boundary which is related to the boundary point coordinate region.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.51.3-51.3
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• 2015

1995년 한국 최초로 VLBI관측이 이루어졌다. 일본 측의 26m 안테나(일본 국토연구원 소재)와 한국 측의 3.6m 안테나(국토지리정보원 소재)로 수행되었으며, 이 때 결정된 관측점의 좌표가 세계 공통으로 사용되는 "세계측지계(ITRF)"에 의거한 새로운 국가기준좌표계의 경위도 원점이다. 그 후 측지VLBI관측국의 설치를 위해, "측지VLBI구축 타당성조사 및 기본계획 수립을 위한 연구(2003년)"와 "측지VLBI구축 실시설계(2006년)"를 수행하였다. 그 결과 국가 차원에서 측지VLBI관측소(22m 안테나)를 건설하기 위해 2008년에 관측소 후보지를 세종시로 확정해서 공사에 들어갔다. 2012년에 준공되었으며, 명칭을 "우주측지관측센터"로 하였다. 그 후 1년 동안의 시험관측의 성공으로 아시아에서 3번째로 정식으로 IVS(International VLBI Service)에 가입하였다. 현재 독일, 일본, 미국 등의 측지VLBI관측국들과 정기적으로 관측을 수행하게 되었으며, 실적을 올리고 있다. IVS사업 뿐 만 아니라, 한국천문연구원의 KVN(천문 VLBI)연구팀과도 공동연구를 수행해서 우리나라의 천문 VLBI 및 측지VLBI관측사업의 활성화에 기여하고 있다. 장차 동남아 각국에 마이크로SAR위성의 관측데이터를 수신하기 위한 지상국(3m급 소형안테나)이 설치되면, 이를 활용해서 측지VLBI관측을 수행할 계획을 수립하고 있다. 이것은 위성용 수신기를 VLBI용 수신기로 교체하면 된다. 한국과 일본이 VLBI관측을 수행했던 것처럼 세종시에 설치된 우주측지관측소가 허브역할을 하면 된다. 즉 동남아 지역에 우주 VLBI관측망을 구축하게 된다.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.59-63
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• 2006

본 연구의 목적은 GPS관측에 의한 세계측지계 성과의 산출방안을 연구하는데 그 목적이 있다. GPS 관측 데이터와 상시관측소의 데이터를 활용하여 세계측지계 성과를 산출하기 위한 방안을 연구한다. GPS 관측 데이터의 후처리 결과 상시관측소의 데이터를 사용하지 않았을 경우와 사용하였을 경우의 폐합차를 분석한 결과 모두 정밀1차 기준점 측량작업규정에 만족함을 알 수 있었다. 또한 GPS상시관측소의 데이터를 활용하여 각 측점 지점의 좌표를 산출한 결과, 상시관측소 3개소의 데이터를 사용하였을 경우에 비해 사용하지 않았을 경우의 오차가 가장 크게 나타났으며 1개소 사용, 2개소 사용할 때 점차적으로 오차가 감소하고 있음을 알 수 있었다. 따라서 상시관측소를 고정점으로 사용하되 적어도 3점이상의 점을 사용하여야 함을 알 수 있었다. 본 연구는 제한된 일부 지역을 대상으로 GPS 상시관측소의 관측 데이터를 사용하여 세계측지계의 성과를 산출 한 연구로 향후 광범위한 지역에서의 GPS 상시관측소의 활용에 대한 심도 있는 연구가 진행되어야 할 것이다.