• Journal of Digital Convergence
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• v.19 no.2
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• pp.195-202
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• 2021

In this study, from a long-term perspective, we tried to find and present a plan to apply the results of transformation of cadastral coordinates to the world geodetic system in stages for cadastral records of graphical and digital cadastral area. There was a case where the difference in area before and after the transformation occurred irregularly in the transformation result of the cadastral coordinate system currently being promoted. In addition, it was found that transformation errors in cadastral non-coincidence areas occurred accumulatively, and the period for acquiring world geodetic results for cadastral reference points was insufficient. In order to solve this problem, the study proposed a plan to provide spatial information and related fields through advancement of continuous cadastral maps, etc. for maps that have been primarily transformed by the end of 2020. In addition, the maps used for cadastral surveying purposes were presented in the direction of applying them to cadastral records in numerical form in the long term to conform to the characteristics of graphical and digital cadastral area. It is expected that more stable cadastral record will be reflected by applying the world coordinate transformation performance by dividing the graphical and digital cadastral area.

• 한국지형공간정보학회:학술대회논문집
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• 1994.04a
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• pp.14-30
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• 1994

Before GPS is practically used in Kores, we must fix a problem on the coordinate transfomation between WGS 84 and Korean geodetic system based on Bessel ellipsoid. On this article, I investigate various coordinate trans formation methods and review the researched results about the coordinate transformation which have been performed in Korea. With the inspection of which method is more applicable to Korea, I discuss about the future prospect and the fixing way for the problem of domestic coordinate transfomation.

• Journal of Korean Society for Geospatial Information Science
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• v.9 no.2 s.18
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• pp.63-71
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• 2001

GPS allows a user with an appropriate receiver to obtain their position anywhere on the Earth's surface. The use of GPs has highlighted the shortcomings of national reference systems, and many countries are in the process of establishing new geodetic frameworks in order to overcome these shortcomings. Korea National Geography Institute has established a new geocentric datum and presented the its time frame for implementation. In this paper, I studied the considerable matters of digital mapping authority and users for converting the geodetic datum and coordinate system and suggested the steps of public relations for GIS users.

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

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.3
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• pp.273-282
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• 2005

A rapidly developed satellite technology is used in comprehensive fields such as spatial data aquisition and applications. Especially a GPS positioning is expected to reinvigorate at the national reference system changes to ITRF (International Terrain Reference Frame). Currently the National Geographic Information Institute (NGII) issues a triangulation point coordinate by separating old and new coordinates and in the year of 2007 it will be scheduled to be changed ITRF. The triangulation point coordinate in Cheju area causes some problems due to the difference original observation and re-observation. Thus in this study a GPS observation is conducted after re-organizing geodetic network based on 1st and 2nd order triangulation in order to check the current triangulation points in Cheju area. After the GPS observation data analysis, stable points were extracted, proposed a geodetic network and its application.

• Journal of Astronomy and Space Sciences
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• v.30 no.4
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• pp.315-320
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• 2013

Space geodetic techniques can be used to obtain precise shape and rotation information of the Earth. To achieve this, the representative combination solution of each space geodetic technique has to be produced, and then those solutions need to be combined. In this study, the representative combination solution of very long baseline interferometry (VLBI), which is one of the space geodetic techniques, was produced, and the variations in the position coordinate of each station during 7 years were analyzed. Products from five analysis centers of the International VLBI Service for Geodesy and Astrometry (IVS) were used as the input data, and Bernese 5.0, which is the global navigation satellite system (GNSS) data processing software, was used. The analysis of the coordinate time series for the 43 VLBI stations indicated that the latitude component error was about 15.6 mm, the longitude component error was about 37.7 mm, and the height component error was about 30.9 mm, with respect to the reference frame, International Terrestrial Reference Frame 2008 (ITRF2008). The velocity vector of the 42 stations excluding the YEBES station showed a magnitude difference of 7.3 mm/yr (30.2%) and a direction difference of $13.8^{\circ}$ (3.8%), with respect to ITRF2008. Among these, the 10 stations in Europe showed a magnitude difference of 7.8 mm/yr (30.3%) and a direction difference of $3.7^{\circ}$ (1.0%), while the 14 stations in North America showed a magnitude difference of 2.7 mm/yr (15.8%) and a direction difference of $10.3^{\circ}$ (2.9%).

• Journal of the Korean earth science society
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• v.30 no.3
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• pp.381-397
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• 2009

The Modem Geodesy monitors physical and geometrical shape and motion of the Earth and, more importantly, its temporal variations with unprecedented precision. It provides accurate and stable reference frames for Earth observations in the Space era. Furthermore, with an aid of interdisciplinary approaches, it also traces the causes of the variations in shape and motion of the Earth and eventually contributes to a better understanding of the Earth system. The International Association of Geodesy (IAG) has established the Global Geodetic Observing System (GGOS) to integrate the multitude of geodetic tools and tried to contribute to the management of global environmental changes as a partner of the Global Earth Observation System of Systems (GEOSS). Here we introduce the contribution of geodesy to the various fields of Earth Science by focusing on GGOS and encourage interdisciplinary researches.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.6
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• pp.717-723
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• 2020

Determination of local tie vectors between the space geodetic techniques such as VLBI (Very Long Baseline Interferometer), SLR (Satellite Laser Ranging), DORIS (Doppler Orbit determination and Radiopositioning Integrated on Satellite), GNSS (Global Navigation Satellite System) is essential for combination of ITRF (International Terrestrial Reference Frame). Therefore, it is required to compute IVP (Invariant Point) position of each space geodetic technique with high accuracy. In this study, we have computed Sejong VLBI IVP position by using updated mathematical model for adjustment computation so that the improvement on efficiency and reliability in computation are obtained. The measurements used for this study are the coordinates of reflective targets on the VLBI antenna and their accuracies are set to 1.5 mm for each component. The results show that the position of VLBI IVP together with its standard deviation is successfully estimated when they are compared with those of the results from previous study. However, it is notable that additional terrestrial surveying should be performed so that realistic measurement errors are incorporated in the adjustment computation process.

• Journal of Advanced Navigation Technology
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• v.24 no.4
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• pp.273-279
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• 2020

In the Korea's SBAS(KASS), reference site is an important infrastructure facility for the collecting and monitoring GPS/GEO signals. The SBAS reference station has an clear requirements than other regular monitoring stations. It requires constant maintenance during the system operation. The development for KRS site should be prepared for site survey, site construction, antenna geodetic survey, equipment installation and operation. Site survey is initially performed as an important step to predict site availability and system performance. The operation center must provide the reference site, equipment room, and appurtenant to satisfy the site requirements. The position of antennas is very important information, and accuracy must be secured through the geodetic survey. Measurement collected at the from precise antenna are provided to the KASS processing station. The position of antenna should be maintained through continuous position checks and updates during the operation. When the development of the KRS site is completed, it performs tasks for installing and operating the KRS equipment. In this paper, we presented the procedures and some results for the development of the 7 KRS sites.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2010.04a
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• pp.201-206
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• 2010

A project for construction of Korea Geodetic VLBI has officially started in Oct. 2008. The construction of all system will be completed by the end of 2011. The project was named Korea VLBI system for Geodesy (KVG), and its main purpose is to maintain the Korea Geodetic Datum. In case of the KVG system, an observation room where an H-maser frequency standard is located is in a building separated from an antenna by several tens of meters. Therefore KVG system will adopt a so-called round-trip system to transmit reference signals to the antenna with diminishing the effect of path length variations. KVG's round-trip system is designed not only available to use either metal or optical fiber cables, but also available to measure path length variations directly by using K5/VSSP32 sampler. We will present principle of round-trip system and the new type of round trip system for KVG.