• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4228-4233
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• 2010

This study analyzed the positional accuracy of cadastral control points where central datum points and eastern datum points meet in the area of standard datum of geographic coordinate, in order to suggest the possibility of converting cadastral coordinates into global coordinates in the future in areas between cadastral datum. 12 GPS observation data points were extracted from the station of triangulation in the experimental area, and the accuracy of coordinate conversions in the area where central and eastern datum points meet was analyzed. The results show that the x-coordinate RMSE was ${\pm}0.0014m$ and the y-coordinate RMSE was ${\pm}0.0011m$. Such excellent results indicated that it is possible to convert to the global coordinate system. Thus, in converting to the global coordinate system, it appears possible to convert even borderline datum point areas if points with stable outcomes are selected by inspecting various triangulation markers, then used to carry out the conversion.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.529-534
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• 2006

New geocentric geodetic datum has recently been realized in Korea, Korean Geodetic Datum 2002- KGD2002, to overcome problems due to the existing Tokyo datum, which had been used in this country since early 20th century. This transition will support modern surveying techniques, such as Global Navigation Satellite Systems (GNSS) and ensures that spatial data is compatible with other international systems. For this realization, very long baseline interferometry (VLBI) observations were initially carried out in 1995 to determine the coordinates of the origin of KGD2002 based on the International Terrestrial Reference Frame (ITRF). Continuous GPS observations were collected from 14 reference stations across Korea to compute the coordinates of 1st order horizontal geodetic control points. During the campaign, GPS observations were also collected at about 9,000 existing geodetic control points. In 2006, network adjustment with all data obtained using GPS and EDM since 1975 has been performed under the condition of fixing the coordinates of GPS continuous observation stations to compute coordinate measurements of the 2nd and 3rd geodetic control points. This paper describes the GPS campaigns which have been undertaken since 1996 and details of the network adjustment schemes. This is followed

• Journal of The Geomorphological Association of Korea
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• v.23 no.1
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• pp.47-60
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• 2016

In this study, datum points measurement have been collected and then weather data have been analyzed to figure out erosion and deposition environmental change around Halmi-island, Baramarae. First of all, it was difficult to analyze geomorphological change which is caused by climate change because of quite short term of collection period of data. However, differences in spatial distribution of erosion and deposition have locally been shown. In all season, the wind is blowing in north and north-west direction mostly except in summer which is shifted to south direction. However, since its ratio which are above 5m/s is much lower than the north and north-west wind, its effect on geomorphological process is very tiny. In order to look at a tendency of erosion and deposition environmental change around Baramarae Halmi-island, the periphery of Halmi-island was classified to east and west part, then accumulated erosion and deposition values have been calculated. As a result, generally, the datum points are located in the west part which are mostly depositional sites. On the other hand, the datum points are located in east part showed the dominant erosion patterns.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.6_2
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• pp.613-623
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• 2007

The main purpose of this study is to investigate the coordinate transformation based on two different systems between local geodetic datum(tokyo datum) and international geocentric datum(new Korea geodetic datum). For this purpose, three methods were used to determine seven parameters as follows: Bursa-Wolf model, Molodensky-Badekas model, and Veis model. Also, we adopted multiple regression equation method to convert from Tokyo datum to KTRF. We used 935 control points as a common points and applied gross error analysis for detecting the outlier among those control points. The coordinate transformation was carried out using similarity transformation applied the obtained seven parameters and the precision of transformed coordinate was evaluated about 9,917 third or forth order control points. From these results, it was found that Bursa-Wolf model and Molodensky-Badekas model are more suitable than other for the determination of transformation parameters in Korea. And, transforming accuracy using MRE is lower than other similarity transformation model.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.69-72
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• 2007

Cadastral control points in Korea are refered to various origins, for example an early separated small triangulation, a separated small triangulation, a separated control surveying origin and an unified origin. We determined transformation parameters from old origin to unified origin using 2D conformal transformation method. To evaluate of transformation accuracy, we compared with GPS field surveying results. And we experiment on coordinate transformations with unified results between the local geodetic datum and the new Korea geodetic datum.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.4
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• pp.309-317
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• 2007

Cadastral control points in Korea are refered to various origins, for example an early separated small triangulation, a separated small triangulation, a separated control surveying origin and an unified origin. Cadastral map with early separated small triangulation origin have difficulties to connect with national GIS data by refered an unified origin. We determined transformation parameters from old origin to unified origin using 2D conformal transformation method. To evaluate of transformation accuracy, we compared with GPS field surveying results. And we experiment on coordinate transformations with unified results between the local geodetic datum and the new Korea geodetic datum.

• Journal of Korean Society for Geospatial Information Science
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• v.10 no.3 s.21
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• pp.29-40
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• 2002

In photogrammetry, the accuracy is analyzed by using the coordinate of the targeted position determined by the geometric principle, thus, the reliability depends on the accuracy of the coordinate of the targeted position. Thereby, geographic surveying is essential to perform such tasks, and it requires approximately $30{\sim}50%$ of total cost and times to produce a finalized map. The main purpose of this study is to determine the configuration of the disposition of minimum datum points and their configuration, which were determined by surveying values available through using the structure of block model based on the aerotriangulation. ortho projection image was produce and digital topographic map was achieved by the optima model(CASE7). We also performed comparative analysis about the result of local datum point and the accuracy of overlapping based on the surveying results. Consequently, it is possible to analyze the unknown position accurately with the optimal model., CASE 7, which is the minimum datum points configuration required to block adjustment. Furthermore, this optimal model, which provides the minimum datum points, results costs and time saving effects compared to the previous methodology.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.373-378
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• 2003

This study deals with development of transformation tool for transformation of digital map coordinates systems using by the best fit transformation parameters which are determined between the local geodetic datum and geocentric datum (ITRF2000) in Korea and distortion modelling derived from collocation method. We used 107 control points as a common points. For analyzing the derived parameters, another 83 common points are tested. Finally, the best fit parameters are determined from Molodensky-Badekas model after considering the RMSE, maximum value, minimum values, and 95% confidence interval of residuals. after transformation of best fit parameters and distortion modelling, we could develop transformation tools with advenced accuracy. so it is possible to perform on transformation of digital map with scale 1:5,000. and we tested accuracy eveluation through analysis between transformation results and field results of GPS observation.

• Journal of Korea Spatial Information System Society
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• v.1 no.1 s.1
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• pp.57-67
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• 1999

Two GIS and/or OGIS issues for ITS interoperability have been proposed and reviewed with some implications to Korean setting. They are location referencing and ITS map datum. The former must support ITS communication and data sharing. Therefore, an introduction of location referencing and other related issues have been addressed along with the Oak Ridge National Lab.'s (ORNL) location referencing scheme. The latter, proposed by ORNL, is a planned network of anchor points across the nation, that could potentially serve as a positional reference for ITS application (Gottsegen, 1997). It is composed of a set of nodes and links in a standard non-plannar network at a coarse scale for the entire nation for referencing purposes. To provide case of real time traffic information and to guarantee the seamless interoperability, we do need to develop the core ITS map datum as a national infrastructure, and the location referencing scheme should also be either developed or borrowed and localized to meet the domestic needs. Some institutional issues are also addressed along with the future research agenda.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.11 no.1
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• pp.31-36
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• 2006

A study on estimation of the datum level is carried out by combining observed and simulated harmonic constants of 4 major tides ($M_2$tide, $S_2$tide, $K_2$tide, and $O_1$tide). In the coastal zone, the datum level can be estimated by using observed tide harmonic constants at tide station. The observed tide harmonic constants, however, cannot be used to calculate the datum level of the sea because of the lack of tide station. In order to estimate the datum level of the sea, it is necessary to adopt the simulated harmonic constants instead of the observed ones. In this study, the datum level is calculated by using the simulated harmonic constants which is modified by tuning coefficient based on relationship between observed and simulated harmonic constants at tide station. Tuning coefficient of sea is interpolated on TIN (Triangulated Irregular Network) which has node points at tide stations.