• 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

• 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.

• Ocean and Polar Research
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• v.23 no.2
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• pp.121-130
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• 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
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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 the Korean Society of Marine Environment & Safety
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• v.1 no.2
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• pp.39-52
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• 1995

There are numerous mapping, charting, geodetic systems and electronic digital products defined in various local geodetic datum. It becomes a straight forward requirement to simplify the complexity by referencing all the products to a common reference globally. WGS-84 is well known as a state-of-the-art global reference system based on the use of data, techniques and technology available within American Defence Mapping Agency(DMA). Its parameters can be translated into more accurate maps, charts and geodetic positioning compared to others previously. Since Global Positioning System(GPS/NAVSTAR), which is asssociated with World Geodetic System(WGS-84)in reference frame, has been widely used, the unified geodetic system has been required for GPS users in many fields.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.17-20
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• 2007

Many countries have changed her geodetic reference system from local system to global system because of the global network's necessity And, also Korean geodetic reference system changed from Tokyo datum to Global geodetic reference system since 2003 as the revision of Survey Law and Korean reference ellipsoid changed from Bessel 1841 ellipsoid to GRS80. Astronomic surveying has been regarded as an important method for absolute positioning of geodetic datum in each countries under the local geodetic reference system. This paper aims to analyses distribution of geoidal heights and ellipsoidal agreement between Bessel 1841 and GRS80 ellipsoid in Korea through comparing both astrogeotic geoidal heights referred to GRS80 and Bessel 1841 ellipsoid by astronomic surveying data which have been surveyed after 1970 in Korea.

• 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.

• Geophysics and Geophysical Exploration
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• v.19 no.4
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• pp.236-248
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• 2016

In this review, the basic concepts of geodetic coordinate system and map projection are explained to practitioners in exploration geophysicists to enhance the understanding of geographic and projected coordinate system. The fundamental elements such as earth ellipsoid, geoid, geocentric and geodetic latitudes, rhumb line, and great circle are dealt with in detail. The geocentric and geodetic coordinate systems are also summarized neatly, together with coordinate conversion formulae. In addition, the concept and technique for datum transforms between local and world datum are presented, with special emphasis on Korean 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 the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.6
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• pp.591-598
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• 2017

This study is for coordinates analysis(geocentric and rectangular coordinate) of Korean geodetic VLBI which has been operated by NGII (National Geographic Information Institute) in Republic of Korea since 2014. The purpose of this study is a fundamental research to determine the Korean geodetic datum. The VLBI data recorded from September 29th 2014 to July 31th 2017, total approximately a hundred of VLBI databases, is used to calculate daily positions and position rates. The VLBI coordinates are based on ITRF(2000,2005,2008,2014) with epochs of the first Korean VLBI observation date(September 29th 2014) and Korean Geodetic Datum(January 1st 2002). And as a results of VLBI observation, Korean VLBI coordinate movement velocity of 3.1cm/yr in the direction of $112.4^{\circ}$.