• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.2
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• pp.141-148
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• 2007

With the use of world geodetic system, the UIS DB of WonJu City, which was established on Korea coordinate system becomes to face the need of coordinates transformation. However, the UIS DB of Wonju City is based on dualistic control points of Korea geodetic system, which means the coordinates system is not standardized. Therefore it is required to establish a plan for transformation into world geodetic system. For this purpose, we calculated coordinate transformation coefficients per control point data of Korea geodetic system and verified the accuracy of transformation coefficients. Through the process, we propose a plan for transforming the coordinate system of UIS DB in WonJu City, which has been based on dualistic control point data of Korea geodetic system, efficiently into the world geodetic system.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.59-63
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• 2007

Each country uses its own datum which well represent its topography. The uses of the space technology such as GPS and the effort of establishing the consistent data over the world, Korea changed the survey act to use a world geodetic system from January 1, 2007. In this study, spatial analysis carried out to transform the GIS DB of electric power distribution system based on the old Tokyo datum the new world geodetic system, KGD 2002. Based on the study, problems on the transformation had been identified and efficient solutions are suggested. The data used for the 7 parameter similarity transformation in this study is the blueprints of the electric equipment and base maps. It is expected that this study provide general scheme and procedure for efficient GIS DB transformation to the new world geodetic system.

• Journal of Digital Convergence
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• v.19 no.2
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• pp.195-202
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• 2021

In this study, from a long-term perspective, we tried to find and present a plan to apply the results of transformation of cadastral coordinates to the world geodetic system in stages for cadastral records of graphical and digital cadastral area. There was a case where the difference in area before and after the transformation occurred irregularly in the transformation result of the cadastral coordinate system currently being promoted. In addition, it was found that transformation errors in cadastral non-coincidence areas occurred accumulatively, and the period for acquiring world geodetic results for cadastral reference points was insufficient. In order to solve this problem, the study proposed a plan to provide spatial information and related fields through advancement of continuous cadastral maps, etc. for maps that have been primarily transformed by the end of 2020. In addition, the maps used for cadastral surveying purposes were presented in the direction of applying them to cadastral records in numerical form in the long term to conform to the characteristics of graphical and digital cadastral area. It is expected that more stable cadastral record will be reflected by applying the world coordinate transformation performance by dividing the graphical and digital cadastral area.

• Journal of Cadastre & Land InformatiX
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• v.49 no.2
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• pp.123-134
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• 2019

The introduction of the world geodetic reference system in cadastral sector can apply the international standardization of cadastral survey and can be the basis for the creation of new industries by merging with other industries based on spatial information. With the introduction of the world geodetic reference system, non-coincidence land may cause problems which are whether the cadastral record and the real estate register are not consistent, etc. This problem infringes on the protection of ownership of citizens suggested in the main purpose of ｢Act On The Establishment, Management, Etc. Of Spatial Data｣. We have analyzed at overlapping cases between private land and overlapping cases between national and public land and suggested institutional improvement measures to solve problems arising on the site. As a result, it will be necessary to introduce a transformation verification measure by the world geodetic reference system in order to assign a function as a cadastral records to mapping converted to the world geodetic reference system. It is also expected that the legal and institutional basis should be established for alert adjustment and positioning through verification measures. Finally, it is difficult to determine the transformation factor as the co-ordinates of common points also differ because survey results vary by work area. Therefore, it is deemed necessary to consider the requirement to use the cadastral measurement basis by the world geodetic reference system in 2021.

• Journal of Cadastre & Land InformatiX
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• v.45 no.2
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• pp.101-116
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• 2015

In Boundary Point Coordinate Register Area, the accuracy on Transformation of World Geodetic System(WGS) is determined by surveying results at the reference point. However, the present surveying result in reference points indicates the irregular performance due to the limitations of measurement techniques and methodologies, moreover, can be contaminated by various error sources from the unique characteristics of each project district and start time of the project. Therefore, the main purpose of present investigation is to conduct an inquest into error cause by project districts for each type in Boundary Point Coordinate Register Area, and propose the improvement plan of surveying accuracy through the WGS Transformation and verification-surveying.

• Korean Journal of Geomatics
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• v.5 no.1
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• pp.21-26
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• 2005

According to revisions of survey law taking effect on January 1, 2003, the Korean geodetic datum has been changed from a local geodetic to a world geodetic system. In this study, the datum transformation parameters especially for the maritime geographical data are determined. From database constructed through MGIS, a total of 492 coordinate pairs were selected and used in the parameter determination after outlier testing. Based on the parameter estimation, the Molodensky model is selected for datum transformation. For higher accuracy, Application of network optimization and a least squares collocation with Gaussian model has resulted in the accuracy better than 15 cm in coordinate transformation.

• 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 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.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.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.1
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• pp.677-682
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• 2009

According to the revised law of survey, all the geographic information data including 1/1,000 digital topographic maps have to be converted to world geodetic reference system by the end of 2009. National Geographic Information Institute (NGII) formulated the policy to promote the conversion from local geodetic reference system to world geodetic reference system. However, the current conversion rate is lower than planned due to some impeding factors. Therefore, in this paper, those impeding factors are investigated and then efficient conversion strategies are established and provided. The research involves the validation of affine transformation, the determination of critical value for outlier detection and optimal number of common control points for coordinate conversion, and the treatment of old and new control points.