• 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.25 no.2
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• pp.141-148
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• 2007

With the use of world geodetic system, the UIS DB of WonJu City, which was established on Korea coordinate system becomes to face the need of coordinates transformation. However, the UIS DB of Wonju City is based on dualistic control points of Korea geodetic system, which means the coordinates system is not standardized. Therefore it is required to establish a plan for transformation into world geodetic system. For this purpose, we calculated coordinate transformation coefficients per control point data of Korea geodetic system and verified the accuracy of transformation coefficients. Through the process, we propose a plan for transforming the coordinate system of UIS DB in WonJu City, which has been based on dualistic control point data of Korea geodetic system, efficiently into the world geodetic system.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.5
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• pp.451-463
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• 2007

This paper describes issues of GPS network adjustment to determine coordinate sets of the $2^{nd}$ order national geodetic control points based on the Korean Geodetic Datum (KGD2002) which has been newly adopted in 2003, After outlining theoretical background of the GPS network processing, the adjustment procedure applied for this project is detailed. Throughout performing a series of minimally constrained adjustments, some outliers have been removed and magnitude of absolute and relative error for a stochastic modeling has been determined as 4mm+0.4ppm and 8mm+0.8ppm in the horizontal and vertical component, respectively. The over constrained adjustment by fixing the $1^{st}$ order control points was performed to derive final solution, indicating that the accuracy of the estimated coordinates was 2cm and 4cm in the horizontal and vertical component.

• Journal of Bio-Environment Control
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• v.14 no.1
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• pp.52-55
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• 2005

An experiment was conducted to evaluate the efficacy of continuous lateral shoot pinching and gradual adjustment of drip irrigation lines in improving plant health as well as fruit yield and quality in white-spined cucumber grown in the greenhouse. Grafted white-spined cucumber seedlings were established at a density of 18,000 plants per ha in a greenhouse. Main stems were pinched at 21st node. Each of the lateral shoots was pinched at the 3rd node and 2-3 fruits per lateral shoot were harvested. Drip irrigation lines were gradually adjusted to provide water to the area of maximum root concentration. Plants grown with these combined treatments produced $55\%$ more lateral shoots and 38% more marketable yield, as compared to the control.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.12 no.1
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• pp.15-24
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• 1994

In order to produce a consistent set of coordinates of the Korea Precise Primary Geodetic Network (PPGN) based on Suwon Datum, PPGN survey with the use of EDM had carried out between 1975 and 1993. In this study, data arrangement and rigorous adjustment was carried out to assess the net strength and local weakness and to evaluate the accuracy of PPGN. ss, specification for PPGN survey would be systematically studied and revised to new technology and field conditions. And basic data for redefinition of official coordinates. of 1st and 2nd triangulation points is obtained.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.9 no.1
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• pp.27-35
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• 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
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• v.28 no.6
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• pp.587-594
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• 2010

This paper describe the optimal design of geodetic network by analytical technique based on the quality criteria of network. We described an example of geodetic network design taking into account the precision, reliability and robustness that are the main criteria of network design. The main goal of this paper is to evaluate the criteria to design the geodetic network coinciding with the criteria of high precision(error ellipse, 2DRMS, CEP), reliability(internal and external reliability) and robustness(maximum shear strain, principal strain, dilatation). The network design parameters computed in this study show that precision and reliability has not much improved by about 2% and 3%, respectively, than the observed network, while robustness has much improved by about 3, 100%. It also shown that maximum errors of precision, reliability and robustness were reduced by 5%, 7% and 16,957%, respectively.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.2
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• pp.183-191
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• 2008

Geodetic Reference System was deferred from 2007 to 2010. Although National Geographic Information Institute in Korea takes charge of it, the progress is slow without clear policy alternatives. In this regards, this study aims at suggesting practical measures for introducing World Geodetic Reference System. Successful foreign countries have well established institutional system for improving their geodetic reference systems. In Korea, National Geographic Information Institute, Ministry of Maritime Affairs and Fisheries, and some municipalities have propelled introduction of the World Geodetic Reference System. However, none of them have systemical approaches. Although National Geographic Information Institute has conducted several researches regarding World Geodetic Reference System, comprehensive policy measures by central governments are not yet made. It suggests methods of data conversion, organizational structures, financial resources, and other supportive measures. Introduction of World Geodetic Reference System is nationwide project. However, there is not nationwide project promotion and management system yet. This research suggests overall policy frameworks to effectively propel World Geodetic Reference System.

• 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 Bio-Environment Control
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• v.10 no.3
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• pp.155-158
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• 2001

The cultivation area of white spined cucumbers for export has continuously increased up to 121 ha in 2000. Since white spined cucumbers set fruits on lateral shoots, fruit yield is dependent upon the development of lateral shoots. Unfortunately, the major cultivation period is during winter season, October to February, when temperature and light are limited for the development lateral shoots. This experiment was conducted to investigate the effect of soil heating on the development of lateral shoots in white spined cucumbers. Number of lateral shoots were 13.7 and 11.7 in the soil heated treatment and in the control, respectively. Number of marketable fruits per plant was 45 in the soil heated treatment as compared to 38 in the control. Fruit yield was 81 ton per ha, an 18% increase, in the soil heated treatment. Soil heating not only increased number of long lateral shoots but also decreased curved fruits.