• Journal of the Korean association of regional geographers
• /
• v.15 no.1
• /
• pp.161-178
• /
• 2009

The introduction of a world geodetic system for cadastral survey will be started the enactment of the law on survey, hydro-graphical examination and cadastre. However, the cadastral control points are not homogeneous and correspond with national control points because of various reasons. To cope with this problem, the 1,600 high accurate control points, which can be interlocked with national GPS control points, has selected from existing 20,000 cadastral control points. These selected control points were calculated as an accurate world geodetic system and it makes a homogeneous cadastral survey network. Through these measures, for the future carrying out national project, this study will be effectively contributed to establish the cadastral infrastructures for the Korea cadastral reform project.

• Journal of Korean Society for Geospatial Information Science
• /
• v.15 no.1 s.39
• /
• pp.47-53
• /
• 2007

Astronomic surveying has been regarded as an important method for absolute positioning of geodetic datum in each countries under the local geodetic reference system. The purposes of this study are to determine astrogeodetic geoidal heights referred to Bessel ellipsoid and to determine deflection of the vertical and geoidal heights referred to GRS80 of World Geodetic System by astronomic surveying data which have been surveyed after 1970 in Korea. The results show that $\xi$ component of the deflection of the vertical distribute from -5.725" to 8.005" and $\eta$ component distribute from -14.917" to 6.2" and astrogeodrtic geoidal heights distribute from 23 m to 27 m in the study area. Also, we could see that GRS80 was more optimal ellipsoid than Bessel 1841 ellipsoid to Korea through comparing both astrogeotic geoidal heights referred to GRS80 and Bessel 1841 ellipsoid.

• Ocean and Polar Research
• /
• v.23 no.2
• /
• pp.121-130
• /
• 2001

Geodetic datums define the size and shape of the earth and the origin and orientation of the coordinate systems used to map the earth. A lot of different datums have been developed and each nation uses its own datum as the basis for coordinate systems used to identify positions in geographic information systems. Recently GPS receivers are widely used to find out location and GPS is based on the World Geodetic System 1984(WGS-84) datum. Therefore the diversity of datums in use today requires accurate conversion between coordinates in different datums. In this study a coordinate conversion program on Windows is developed to transform between Tokyo Bessel(1941), which is the reference datum in Korea, and WGS-84. Several examples of coordinate conversion are presented and computed results are tested and proved to be correct.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.9 no.1
• /
• pp.27-35
• /
• 1991

The total station which is able to measure angles and distances simultaneously, and G.P.S., 3-dimensional satellite surveying system will be employed as important equipments for establishing and re-adjusting large geodetic networks. The objective of this study is to suggest possibilities of application of combination adjustment by means of studying characteristics of networks adjusted according to detection gross errors included in angles and distances by least square method. It is expected that the results of this study were used for determination of national geodetic networks but also large or small construction site.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.3 no.2
• /
• pp.11-17
• /
• 1985

In the three dimensional Cartesian Coordinate System such as the satellite geodesy the relationship of the geoid and the reference ellipsoid must be known. Therefore, the determination of geoidal heights is regarded as one of the most important problem in geodesy. This paper deals with determination of astro-geodetic geoid by the spherical surface polynomials interpolation method. The data that astronomical deflection of the vertical was published by National Geography Institute is applied. The map of geoidal heights is drawn out. This shows that Tokyo Datum have influenced on Korea.

• Spatial Information Research
• /
• v.22 no.1
• /
• pp.35-43
• /
• 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
• /
• v.36 no.4
• /
• pp.235-243
• /
• 2018

The national geodetic control point is very important as a framework for drafting plans for construction and civil engineering works as well as mapping for various development and utilization plans related to the national land. Since the 1910s, Korea has established and managed the national geodetic control points, the triangulation points and the benchmarks. Currently, these point information is provided through the land information platform. The national geodetic control point has been changed through the process of loss, re-establishment, and re-location by the events and environment of the times. Therefore, it is very important to provide information by linking these past national geodetic control points in time series. In this study, we classified the triangulation points into five groups(Japanese Government General of Korea, YUCCA Project, National Construction Institute, Past Control Point Data Sheet, and Current) by age and then suggests a method to match the same control points in each time period. Finally we also applied the proposed method to Jecheon and analyzed the results.

• Structural Monitoring and Maintenance
• /
• v.8 no.4
• /
• pp.309-328
• /
• 2021

The objective of this work was to develop a methodology for geodetic monitoring on onshore wind towers, to ascertain the existence of displacements from object points located in the tower and at the foundation's base. The geodesic auscultation was carried out in the Gravatá 01 and 02 wind towers of the Eólica Gravatá wind farm, located in the Brazilian municipality of Gravatá-PE, using a stable Measurement Reference System. To verify the existence of displacements, pins were implanted, with semi-spherical surfaces, at the bases of the towers being monitored, measured by means of high-precision geometric leveling and around the Gravatá 02 tower, concrete landmarks, iron rods and reflective sheets were implanted, observed using geodetic/topographic methods: GNSS survey, transverse with forced centering, three-dimensional irradiation, edge measurement method and trigonometric leveling of unilateral views. It was found that in the Gravatá 02 tower the average rays of the circular sections of the transverse welds (ST) were 1.8431 m ± 0.0005 m (ST01) and 1.6994 m ± 0.0268 m of ST22, where, 01 and 22 represent the serial number of the transverse welds along the tower. The average calculation of the deflection between the coordinates of the center of the circular section of the ST22 and the vertical reference alignment of the ST1 was 0°2'39.22" ± 2.83" in the Northwest direction and an average linear difference of 0.0878 m ± 0.0078 m. The top deflection angle was 0°8'44.88" and a linear difference of ± 0.2590 m, defined from a non-linear function adjusted by Least Squares Method (LSM).

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.11 no.4
• /
• pp.143-150
• /
• 1991

This paper presents an overview of a system of computer programs for the solution of a large geodetic network of about 2,000 stations. The system arranges the matrices in systematic sparse form which is applied to observation equations of RR(C)U (Row-wise Representation Complete Unordered) type and to normal equations of RR(U)U (Row-wise Representation Upper Unordered) type. The solution is done by a Modified Cholesky's algorithm in view of large networks. The implementation program are tested in PC-386 by korean new secondary networks, the results show that the sparse techniques are highly useful to geodetic networks in core-storage management and processing time.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.1 no.2
• /
• pp.42-59
• /
• 1983

This article investigates the situation of the Plane Rectangular Coordinate derived from the Gauss Double Projection whereby the positioning of triangulation point in Korea has been represented on. Analyzing and assessing it have been performed by means of new computational method such as computer programing. On the basis of the results brought about, it is found that a new Plane Rectangular Coordinate as well as map projection and scale factor of geodetic length may be adapted to improve the distortion along the geodetic line on a certain zone of map projection in order to enhance the accuracy and the utility of the practical surveying works. The proposals for this study are as follows; (1) projection: Gauss-Kruger's projection (2) Coordinate system: Plane Rectangular coordinate with 8 origin system (3) Scale factor of geodetic length in origin; $m_0=0.9999$