• 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.19 no.2
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• pp.199-208
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• 2001

The digital map in Korea has been producted and utilized independently according to scales such as 1:1,000, 1:5,000, and 1:25,000. Therefore, whenever we need to obtain the spatial data of other scales, we have to product the digital maps over and over again which it is time-consuming and ineconomic. To solve these problems, it has been accomplished many researches on map generalization to make digital maps in small scale from the master data of large scale. This paper aims to analyze the conversion characteristics of the large scale to the small scale by simplification of map generalization. For this purpose, it is proposed the algorithm for the simplification process of digital map and it is investigated the simplification characteristic of digital map through the experiment on the conversion of 1:5,000 scale into 1:25.000 scale. The results show that Area-Preservation algorithm indicates the good agreement with the original data in terms of the area and features of building layer compared to Douglas-Peucker algorithm and Reumann-Witkam algorithm.

• 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.

• Proceedings of the KSRS Conference
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• 2007.03a
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• pp.109-112
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• 2007

본 논문에서는 대축척 수치지도와 Quickbird 위성영상의 자동 보정을 영상공간에서 수행한다. 알고리즘은 보정변환식의 초기 계수값 결정과 정확한 변환계수 결정과정으로 나뉜다. 초기 계수값 결정은 보정변환식의 상수항을 결정하는 것으로 수치지형도의 지면개체와 영상에서 추출된 에지의 논리곱 연산을 적용하여 최적값을 추정하는 방식을 용한다. 보정 다항식의 정확한 변환계수를 결정하기 위하여 수치지형도의 지면 선형개체 점데이터와 영상의 에지개체 점데이터간 ICP 조정을 수행하였다. 제안된 방법의 정확도를 평가한 결과， 영상공간에서 1.72화소의 RMSE를 나타내었다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.19 no.2
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• pp.173-181
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• 2001

It is very important to assess spatial data quality of a digital map produced through digital map generalization. In this study, as a aspect of spatial data quality maintenance, we examined the tolerate range of theoretical expectation accuracy and established the quality assessment standard in spatial data for the transformed digital map data do not act contrary to the digital map specifications and the digital map accuracy of the relational scale. And, transforming large scale digital map to small scale, if we reduce complexity through processes as simplification, smoothing, refinement and so on., the spatial position change may be always happened. thus, because it is very difficult to analyse the spatial accuracy of the transformed position, we used the buffering as assessment method of spatial accuracy in digital map generalization procedure. Although the tolerated range of generic positioning error for l/l, 000 and l/5, 000 scale is determined based on related law, because the algorithms adapted to each processing elements have different property each other, if we don't determine the suitable parameter and tolerance, we will not satisfy the result after generalization procedure with tolerated range of positioning error. The results of this study test which is about the parameters of each algorithm based on tolerated range showed that the parameter of the simplification algorithm and the positional accuracy are 0.2617 m, 0.4617 m respectively.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.2
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• pp.121-134
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• 2013

The transverse cylindrical projection has been used in Korea since 1910s when the nationwide geodetic network was firstly established. However, the projection has a number of different types of functions according to a way of its mathematical derivation as well as a section of its coefficients and terms, for instance Gauss- Schreiber(GS) and Gauss-Kruger(GK) types. Although the transverse cylindrical projection itself is assigned to a system, projected coordinates would be diverse with respect to the function used in the actual calculation. In order to investigate impact of functions used in the computation, five different equations (i.e., 2 GS and 3 GK) were implemented in this study by using MATLAB. A series of numerical simulation tests has been carried out to compare and characterize them in terms of projection accuracy, difference of projected coordinates and distortion. Furthermore, a comparison between GS and GK function was made under the Korean gridding system, consisting of four zones. Results from the numerical computations were qualitatively analyzed and summarized in this paper.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04b
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• pp.1041-1044
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• 2002

1990 년대 이후 NGIS(National Geographic Information System) 사업의 시작과 함께 활성화 되기 시작한 GIS 는 1990 년대 말 인터넷의 급속한 보급으로 인하여 비약적인 발전을 거듭하였다. 근래에 들어, 무선 인터넷의 확산과 함께 모바일 GIS 가 등장하게 되었으나, 기관이나 기업의 서로 상이한 GIS 데이터베이스는 중복투자와 함께 데이터베이스간의 이질성을 초래하였다. 본 논문에서는 국립지리원에서 제공하는 DXF(Drawing exchange Format) 형식의 국가기본 수치 지도를 지리정보의 저장과 전달을 위해 OGC(Open GIS Consortium)에서 제안한 GML(Geographic Markup Language)로 변환하는 시스템을 제안한다. 클라이언트로부터 위치정보와 축척정보를 입력받아 검색범위를 설정한 후, 검색된 DXF 를 GML 로 변환하여 클라이언트로 전송하고, 클라이언트는 전송 받은 GML 문서를 모바일 C 로 구현된 GML 파서를 통해 변환하여 모바일 디바이스의 화면에 출력하고, 사용자 상호작용을 수행한다.

• Water for future
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• v.28 no.5
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• pp.117-127
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• 1995

The application and analysis for the scale considering GIUH model proposed by the authors in this issue have been performed for the leemokjung sub-basin in the Pyungchang basin one of IHP representative basin in Korea. Scales of topographic maps for model application and fractal analysis are 1:25,000, 1:50,000 and 1:100,000. The ratio between successive scales is therefore constant. Link lengths were measured using a curvimeter with the resolution of 1 mm. Richardson's method was employed to have fractal dimension of streams. Apparent alternations of parameters were found in accordance with variations of map scale. And this tendency could mislead physical meanings of parameters because model parameters had to preserve their own value in spite of map scale change. It was found that uses of fractal transform and Melton's law could help to control the scale problem effectively. This methodlogy also could emphasize the relationship between network and basin to the model. To verify the applicability of GIUH proposed in this research, the model was compared with the exponential GIUH model. It is proven that proposed 2-parameter gamma GIUH model can better simulate the corresponding runoff from any given flood events than exponential GIUH model. The result showed that 2-parameter gamma GIUH model and fractal theory could be used for deriving scale considered IUH of the basin.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.10a
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• pp.266-267
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• 2008

건설도면 CAD자료와 GIS자료를 연계하기 위해서는 임의의 좌표체계와 축척으로 표현된 건설도면 CAD 자료를 GIS 자료의 지도좌표로 변환하기 위한 과정 이 수행되어 야 한다. 본 연구에서는 준공과정에서 제출되는 건축물 CAD배치도상의 인접대지경계선 폴리곤과의 연속지적도상의 개별 필지 경계선의 형상 정합과정을 수행함으로써 좌표변환에 필요한 변수를 도출해 보았다. 이렇게 도출된 변환함수를 배치도면상의 건물경계선과 같은 다른 객체에 적용함으로써 개별 CAD자료를 GIS 자료에 연계할 수 있는 실좌표 부여 방법을 적용하고 평가해 보았다.

• Journal of Korean Society for Geospatial Information Science
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• v.2 no.1 s.3
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• pp.93-98
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• 1994

This image of Kangseogu in Pusan, is a digital merge of aerial photos by scale of 1/1,200 map. The merge was carried out 2nd affine and bilinear interpolation. It can improve digital classification to help choose training sites and interprete classification results, and improve visual interpretation, as in this case, by adding detailed information to the multispectral TM data.