• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.spc4_2
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• pp.401-412
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• 2014

This study is purposed on showing an effective process for coordinate transformation of cadastral maps, based on the local datum, in the World Geodetic System (WGS) for Cadastral Reform Project (CRP). The process follows three steps: coordinate adjustment, datum transformation and distortion modeling. The first procedure is that point coordinates on local datum has to be adjusted by those GPS observed point-to-point distances, using trilateration. Secondly, the adjusted coordinates need to be transformed to WGS by applying the Affine model, while the verification of the methodology is implemented under numerical experiments. To conduct this procedure, 195 points in the same coordinate origins in Seoul and 61 points in several different origins in Incheon are used in the estimation. As a result, there are less than 2cm coordinate differences between transformed coordinates and measured ones at everywhere. Also, it is remarkable that the transformation does not depend on either of the particular common points or the sizes of computed region. Therefore, this suggested methodology is expected to easily provide identifications and corrections for points-deviations for improved quality of the cadastral map by distortion modeling through CRP.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.11 no.4
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• pp.163-170
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• 1991

The 3 dimensional point positioning from SPOT imagery is performed by bundle adjustment methods of analytical and digital photogrammetry, and need the precise determination of image coordinates and accurate coordinates of ground control points. In this study, the authors analysed the digitized planimetric accuarcy and height accuracy of topographic maps in comparison with accurate coordinates by coordinates resulted by bundle adjustment in each cases between different acquisition method of ground control point coordinates and formats of SPOT imagery.

• 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 the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.16 no.2
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• pp.195-202
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• 1998

In this study, we utilized various type of GPS observation measurements to get a camera projection center of the aerial triangulation and consequently to determine which type is acceptable. For the accuracy and the error analysis, comparison between a projection center from the conventional model adjustment and the result determined by the kinematic DGPS positioning which is fitted to the conventional model adjustment using 3D conformal transformation method has been made. The camera projection center is located within a $\pm{2m}$ for C/A code range measurements, $\pm{14cm}$ for L1 phase measurements and $\pm{10cm}$ for L1/L2 phase measurements with $1\sigma$. In this way, the accuracy of the camera projection center by the bundle block adjustment can be predicted.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.13 no.1
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• pp.107-113
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• 1995

Generally, the objectives of the geodetic network adjustments are for solving the configuration of geodetic net-works and the problem of observation plans. In this study, assuming that the configuration is fixed, for improving the accuracy of geodetic networks, we focus on choosing adjustment control points and adjustment methods. By choosing adjustment control points and adjustment methods, the adjustment result accuracy of national geodetic networks can be different. So, in this study, we introduce the algorithm that use free network adjustment concept to minimize the displacements of new station points but fixing existing control points. Then, us-ing adjustment results, we can check the errors of existing control points. After checking the errors of existing control point, in case of severe error points in existing control points, we change those points into unknown station points and repeat the algorithm to optimize the coordinates of new station points. As applying this algorithm to simulation network, we can check the errors of existing control points. And changing severe error points into unknown station points, we can decrease the errors of network and optimize the coordinates of new station points. From the results of simulation network adjustment, we think that, as applying this algorithms to sequential adjustment of geodetic network and public surveying that using national geodetic network, the accuracy of network adjustments can be improved.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2001.10a
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• pp.17-44
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• 2001

지적도는 모든 지도중 가장 큰 대축척 지도이며 토지에 대하여 필지별로 지번, 위치 및 경계 등 소유권의 범위를 등록하는 것으로서 국민의 기본권리인 토지에 대한 소유권과 그 이용을 보장할 수 있는 가장 기본적인 특성을 가지고 있다. 도형자료인 현재의 지적도는 1910년 토지조사사업에 의하여 실제 토지필지를 1/1,200로 축소하여 도면에 등록한 도해지적으로 제도오차, 축척오차, 신축오차, 도곽접합 등의 기술적인 오차와 측량을 할 때마다 각기 측량사에 따라 개인오차의 누적으로 성과결정에 있어서 차질을 가져다주고 있다. 따라서 이러한 문제를 해결하기 위하여는 지적재조사사업이 가장 바람직하지만 복잡한 과정을 거쳐야 함으로 그 이전에라도 축척변경사업을 통하여 새로운 지적체계로서 토지이용상태에 따라 토지의 경계를 수치좌표로 등록하는 수치지적체계로 전환하여 지적측량의 정확도와 정밀도를 높여 지적불부합지에 대한 민원을 해소함으로써 재산적 가치를 증대할 뿐만 아니라 국민의 소유권 보호 및 양질의 서비스 개선에 그 목적이 있다. 본 연구에서는 해당지역의 지적도를 독취, 정도곽으로 보정하여 일필지를 공부상면적의 공차범위 이내로 조정한 후 현형도와 지적도를 조정(Orientation)하여 좌표를 저장하였다. 일필지 좌표결정 방법에는 CAD기능을 이용하여 컴퓨터의 모니터에서 지적도를 이동 및 회전함으로써 위치를 결정하는 방식, 모니터상에서 국부적으로 위치를 결정하는 방식 및 디지타이져상에서 결정하여 모니터상에서 조정하는 방식있다. 현실적으로 국부적인 방법이 합리적이라고 생각되어 모니터상에서 조정(Orientation)하여 국부적으로 좌표 위치를 결정하는 방법으로 연구하고 성과를 비교, 검토하였으며, 그 결과 다음과 같은 결론을 얻었다. 1. 지적도면은 토지조사사업 한지를 배접한 켄트지를 사용함으로써 종이의 신축으로 인하여 정도곽으로 보정을 하면 독취면적은 대부분 공부상면적보다 늘어났다. 2. 좌표의 이동량이 일률적이지 못하므로 기초점에 대한 문제라고 생각되며, 따라서 도해지적을 수치지적으로 전환함에 있어서 가장 우선되어야 할 사항이 기초점 정비라 하겠다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.7 no.2
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• pp.35-43
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• 1989

The improvements of highly accurate and dense control networks are major requirements to carry out numerical surveying and a large scale mapping for cadastral renovation. In the most conventional photogrammetric solutions, adjusted control coordinates have been applied to block triangulations. However, this study, imploying real data and those of simulated as well, contributes to a simultaneously combined adjustment. It also contains such photogrammetric as photocoordinates and geodetic observations like distances, angles and hight differences. Its purpose is to introduce the improved results, despite it is not sufficient for the ground network. In addition, through the detection of gross error, more precise observational data can be selected for the better adjustment. All in all, the result of this study can be summarized as follows : First, even if the ground control points are not sufficient nor existed at all, the combination of pbotogrammetric and geodetic observations are improved its accuracy. Secondly, the case #2 is more accurate than that of #3, and the case #7 comes into close to that of #6.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.16 no.1
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• pp.85-94
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• 1998

In year 1996, the National Geography Institute(NGI) carried out a National Fundamental Network survey. A total of 220 baselines between 31 stations were occupied that the baseline length is 40 km-120 km(mean 67.4 km). A minimally constrained network adjustment with three dimensional baseline vectors, was carried out holding geocentric ITRF94 coordinates of the station SUWON which are determined by eccentric observations from the VLBI station. This paper shows KTRF94 coordinates of fundamental stations which accuracies are estimated 1 cm in horizontal and 3 cm in vertical. Also, the coordinates are compared to WGS84 and/or KGS95.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.4
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• pp.139-146
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• 1987

The 3-dimensional deformation measurement by the terrestrial photogrammetry is consist of 3-dimensional coordinates computation, displaced point detection and deformation estimation of object targets. In this study, at the first step of deformation analysis, the variation of the variance-covariance matrix for the exterior orientation elements was analyzed by the increment of the ground control points and the photos in the Bundle adjustment. And then, to give the constraints for improving accuracy of ground control points, the concept of Free-Network adjustment was applied to Bundle adjustment. As a result, we knew that it was desired in the accuracy and the economy, the observation time when the numbers of ground control point and photo were respectively 6 points and 3 photos. In addition, in the case of applying the concept of Free Network adjustment in Bundle adjutment, it was desirable that the space distance for the constraints is distributed outside.

• Journal of Korean Society for Geospatial Information Science
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• v.3 no.1 s.5
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• pp.37-44
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• 1995

Cartesian coordinate systems used in national base map have 3 zones. If these coordinate systems are used at navigable digital maps without modifications, the edge-matching errors will occur near the edge of two zones. Therefore, it's required to eliminate separate zones of national plane coordinates system suitable far navigable digital map, we choose TM projection that is used at national base map but changed the location and the scale distortion of antral meridian.