• KSCE Journal of Civil and Environmental Engineering Research
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• v.6 no.1
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• pp.51-60
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• 1986

With the improvement of the accuracy of EDM and theodolite, three-dimensional geodetic coordinates can be determinated by means of analytical Intersection & Resection using vector approach. In this paper the accuracy of Resection, Intersection and Multilateration, by which the geodetic coordinates of a unknown point are determinated using the geodetic coordinates, horizontal angles, vertical angles, and slope distances to a known point are analyzed. As a result, it is found that the solution of multilateration method converges into an allowable limit and the method is better than other two methods in accuracy. And it is found that if the known points are over five points, the solution of Resection and Intersection method can also converge into an allowable limit.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.3
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• pp.229-236
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• 2003

This study recorded an object using a digital video recorder, and then tried to estimate 3-D positional information and to reconstruct an image. Firstly, the accuracy of measurement results from a video recorder was evaluated and tested for an applicability, then it applied to a real object to construct 3-D digital model. This study assumed that there is no lens distortion in a video recorder, and all bundles should precisely pass through the projection center of a lens. The image size for orientations is determined by the size of CCD chip and the number of pixels. The average squared error from the result by a digital video recorder and that by triangular survey from 1-second theodolite shows 0.0173m error in x,y coordinates. Without knowing the accurate information on the lens distortion and the coordinates of the projection center, this study reasonably produces acceptable results in the reconstruction of 3-D model. In consequence, this study found that the image from a digital video camera can be reconstructed 3-D model only from the information on a camera type.

• 한국지구물리탐사학회:학술대회논문집
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• 2008.10a
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• pp.7-11
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• 2008

기상청은 2008년 현재 전국에 107개의 디지털 지진관측망을 운영하고 있다. 또한 지진관측 유관기관인 한국지질자원연구원, 한국원자력안전기술원, 한전전력연구원에서 각 기관의 목적에 맞게 지진관측소를 운영하고 있으며, 이들 지진관측자료의 공유를 목적으로 실시간으로 통합하는 통합지진과측망(KISS)을 2000년에 구축하여 지진분석에 쓰이고 있다. 한반도의 지진발생 현황은 1978년부터 2007년까지 776회로 약 26회/년 정도가 발생하였다. 최근 중국의 쓰촨성과 일본 이와테 지진으로 지진 및 지진예지에 대한 국민적 관심이 대두되고 있다. 한반도에서도 큰 규모의 지진이 발생할 가능성에 대비해 기상청에서는 지진관측망과 지진예지 목적의 지구물리관측망을 구축 중에 있다. 지구물리관측망은 INTERMAGNET에서 등록할 수 있는 수준의 관측소를 목표로 인위적인 자기장의 교란이 적은 지질학적인 요소들을 고려한 후보지 선정을 위하여 지구자기업무에 관한 기획연구(서만철 2007)를 수행 하였다. 그 결과 국가 중심 지구자기관측소의 위치는 충남 공주시와 청양군 사이에 있는 칠갑산 지역이 가장 좋은 후보지라고 제안하여 청양지역을 주변으로 국유림 및 군유지를 조사하여 충남 청양군 장평면 화산리 산 36-2번지에 후보지를 선정하여 최적의 입지 조건을 검증하기 위해 인천교육대학교의 이휘순 교수 MT탐사를 수행 주변의 배경잡음을 측정하여 양호한 조건을 갖춘 것으로 확인되었다. 지구자기관측소에는 Fluxgate Magnetometer 1대, Total field Magnetometer 1대, Theodolite 1대, SP(Self Potential) Monitoring system 1대와 장비들을 보호 할 수 있는 관측소가 설치될 예정이다

• Journal of Korean Society for Geospatial Information Science
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• v.3 no.2 s.6
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• pp.75-82
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• 1995

The calculation of astronomic latitude and longitude have been carried by astrolabe, theodolite. Conventional procedures to determine it require clear weather conditions, time high cost. So we need more effective method to decide them. The objective here is to present method to computate astronomic latitude and longitude by mixing GPS observation result and geodetic height. Also to decide geodetic height we used GPS/leveling, DMA(n=m=180) and OSU91A(n=m=360) methods. Compared to conventional procedures we could obtain astronomic latitude and longitude using GPS by $1{\sim}3'$ difference. If the precise geoid model of Korea will be developed, we can compute astronomic latitude and longitude effectively using GPS observation only.

• Publications of The Korean Astronomical Society
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• v.29 no.3
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• pp.53-58
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• 2014

We improved the antenna efficiency of the Taeduk Radio Astronomy Observatory (TRAO) 13.7-m radio telescope by adjusting the antenna panels based on digital photogrammetric measurements. First of all, we measured the surface accuracy of the main reflector of this antenna at three elevation angles of $35^{\circ}$, $45^{\circ}$, and $60^{\circ}$. We performed a total of four sets of the photogrammetric measurements and panel adjustments. When adjusting the panels, we positioned the antenna to the zenith and applied the measured data sets at the elevation of $45^{\circ}$. We found that the antenna surface accuracy has been improved by a factor of ~ 3 times after the final adjustment in comparison with the value before the adjustments. And we also found that the antenna surface accuracy tended to be slightly better at the elevation angles of $35^{\circ}$ and $60^{\circ}$ than that at the elevation angle of $45^{\circ}$. After the final panel adjustment, the aperture and beam efficiencies of the telescope have has been improved from 35% to 44%, and from 41% to 51%, respectively.

• Journal of the Korean Geotechnical Society
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• v.24 no.2
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• pp.59-65
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• 2008

Digital close-range photogrammetric technique can measure and describe 3D geometric farm from 2D image. This technique is increasingly applied in the field of sciences. In the fields of civil and mechanical engineering, which need precise measurements for design, expensive measuring equipments are widely used. In occasions where visual inspection is required in addition to other forms of measurements, appropriate measuring equipments have not been yet available. This study utilizes digital close-range photogrammetric technique to quantitatively analyze behavior patterns before and after destruction from test model of reinforced-soil wall. Then the results are compared with the measurements obtained using digital theodolite to verify the reliability of the proposed method.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.4
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• pp.95-103
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• 1984

This paper is a study on improving the accuracy of control points by suggesting angular requirements which make geometric conditions to be optimum. For this purpose, a equation, by which the accuracy of control point coordinates measured in an arbitrary station can be estimated, is derived. This equation is integrated and average standard error of the coordinates is computed, so that the optimum location of observatory station is determined. In the case of triangulation, a regular triangle has been generally considered as the best geometric condition, but because the precision of each side is different, the $52.77^{\circ}$ isosceles triangle is founded to be the best one. Also in trigonometric leveling, the geometric condition is founded to be optimum when the base angle of a isosceles triangle is $45^{\circ}$. In control surveying for close-range photogrammetry the optimum relation between base length($B_0$) and object distance($D_0$) can be founded to be as follow; $D_0=0.357587-0.357967B_0+0.308555B_0{^2}$.