• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2004.03a
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• pp.499-505
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• 2004

현재 국내에서 활발히 이루어지고 있는 GPS 정밀측지측량은 획득된 GPS 관측값의 결과값이 GPS 기준점의 기하학적 강도와 분산계수의 상관관계의 연관성과의 분석없이 사용되고 있는 문제점을 파악하고 육지와 해상의 통합지리정보시스템구축을 위한 수치지도와 전자해도의 통합투영의 필요성에 의해서 이루어졌다. 본 연구의 목적은 크게 GPS 관측값의 정밀도를 향상시키는 방법과 수치지도와 전자해도의 통합투영으로 GPS 기준점들을 이용한 수치지도와 전자해도상의 경계선 오차량을 비교검토를 통해 수치지도와 전자해도의 통합관리의 방향을 제시하는데 있다. GPS 관측값의 정밀도 향상을 위한 방법제시를 위하여 GPS 망조정에 사용되는 3점의 기준점에 대한 기하학적인 강도에 따른 정밀도 분석방법과 분산계수의 변화에 따른 GPS 관측값들의 정밀도 분석방법으로 나누어 검토하였다.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.551-555
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• 2004

본 연구는 건설교통기술혁신 사업의 일환으로 '국가기준점의 관리 및 위치정보서비스 제공을 위한 전자표지석 개발' 과제에 관한 연구내용 및 결과를 중심으로 하고 있으며, 주 내용은 2차 년도 연구에서 수행한 TOA(Time Of Arrive) 방식을 적용한 전자표지석 개발에 관한 것이다. 본 연구의 궁극적인 목적은 국가기준점을 효율적으로 관리하기 위한 새로운 방안을 제시하는 것으로, 기준점의 현황을 실시간 모니터링하고 기준점의 위치파악을 용이하게 할 수 있는 시스템을 연구하는 것이다. 이를 위해 기준점의 현황을 모니터링 가능하도록 기준점의 움직임을 파악할 수 있는 센서를 부착하였고, 편리한 기준점 위치파악을 위하여 TOA(Time Of Arrive) 방식을 적용한 전자표지석의 설계 및 시제품을 제작하였다. 연구결과를 기준점 관리에 활용하기 위한 시제품을 개발하였다.

• Spatial Information Research
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• v.18 no.5
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• pp.37-45
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• 2010

AT(Aerial Triangulation) is the essential procedure for creating orthophoto and transforming coordinates on the photographs into the real world coordinates utilizing GCPs (Ground Control Point) which is obtained by field survey and the external orientation factors from GPS/INS as a reference coordinates. In this procedure, all of the GCPs can be collected from field survey using GPS and Total Station, or obtained from digital maps. Collecting GCPs by field survey is accurate than GCPs from digital maps; however, lots of manpower should be put into the collecting procedure, and time and cost as well. On the other hand, in the case of obtaining GCPs from digital maps, it is very difficult to secure the required accuracy because almost things at each stage in the collecting procedure should rely on the subjective judgement of the performer. In this study, the results from three methods have been compared for the accuracy assessment in order to know if the results of each case is within the allowance error: for the perceivable objects such as road boarder, speed bumps, constructions etc., 1) GCPs selection utilizing the unique LiDAR intensity value reflected from such objects, 2) using LiDAR DSM and 3) GCPs from field survey. And also, AT and error analysis have been carried out w ith GCPs obtained by each case.

• Journal of the Korea Society of Computer and Information
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• v.20 no.2
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• pp.99-112
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• 2015

Datum point for displaying location and altitude of point has being advantage usefully in various measurement parts. However, datum point has been increasing loss cases owing to weather changes and stratum changes and neglecting meaninglessly. In this paper, we design and implement a multi electronic measurement system monitoring software with functions such as include maximize utilization of existing measurement datum system as well as collected various environment data and detection stratum changes of surround area. Proposed software is implemented to support that reusability and extensibility of software using object oriented modeling method. Our software supports a GUI for electronic measurement datum point administrator as well as for web user and mobile user. Our system can support a graph GUI for various data analysis and reposition in realtime to database that measured location information and various sensing information to prevent loss of electronic measurement datum point and to detected stratum changes. In addition, we include a QR code and RFID recognition function. Finally, we suggest performance evaluation result to confirm stratum changes detection and GPS location error rate.

• 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.

• Journal of the Korean Geophysical Society
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• v.9 no.2
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• pp.87-97
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• 2006

LIDAR(Light Detection and Ranging) is a new technology for obtaining DEM(Digital Elevation Model)ewith high density and high point acuracy. As LIDAR emerged, DEM could be developed in the earthsurface more efficiently and more economically, compared to the conventional aerial photogrametry.In this study, a digital camera is simultaneously used in combined LIDAR surveying, and acquired digitial image and DEM produce digital orthoimage. In this process, methods of combining sensor andorthoimage, GCPs determined by GPS surveying are used. Two digital orthoimage are produced; onewith a few GCP and the other without them. The produced maps can be used to corect or revised1:1,000 or 1:5,000 scale maps acordingly.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.1
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• pp.153-160
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• 2010

It is necessary to determine accurate 3-dimensional coordinates of the building corner points that could be control or check points in order to verify the accuracy of 3D digital maps in the near future. The usual process of obtaining the coordinates of the building corner points is to set up the ground control points with a GPS and then to practice terrestrial survey such as distance or angle measurements. However, since an error in the ground control points can be propagated through the terrestrial survey into the final coordinates of the buildings, accurately should be considered as much as possible. The actual effect of the GPS-derived ground control point error on the estimates of the unknowns through the terrestrial survey is mathematically analyzed, and the simulation data is tested numerically. The error of the ground control points is tested in the cases of 1-4 cm for the horizontal components and 2-8 cm for the vertical component. The vertical component error is assigned twice the horizontal ones because of the characteristics of the GPS survey. The distance measurement is assumed for convenience and the precision of the estimated coordinates of the building corner points is almost linearly increased according to the errors of the ground control points. In addition, the final estimates themselves can vary by the simulated random errors depending on the precision of the survey instrument, but the precision of the estimates is almost independent of survey accuracy.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.2
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• pp.173-180
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• 2012

The most recent, 80 mega pixels digital camera appeared through the development of digital technology, and nonmetric digital cameras have been using in various field of photogrammetry. In this study, we experimented lens calibration using aerial photographs and ground control points. The aerial photographs were taken a non-metric digital camera which is CMOS(Complementary Metal Oxide Semiconductor) 21.1 mega pixels sensor and 35mm lens at a helicopter. And the ground control points were selected on the 1:1,000 plotting origin data. As a result, we calculated focal length, PPA(Principal Point of Autocollimation) and symmetric radial distortion coefficients from the lens. Also, RMSE(root mean square error) and maximum residual of the ground control points from the aerial triangulation were compared before and after calibration. And we found that the accuracy of the after calibration was improved very significantly.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.14 no.2
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• pp.209-218
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• 1996

This study aims to draw a technique for practical using of GPS surveying to decide the positions of cadastrial control points. GPS surveying is carried out at cadastrial triangulation points and supplementary control points. This paper includes characteristics of transformation of WGS84 into Tokyo datum, two dimensional solutions for GPS baseline vector, and combined solutions of both GPS and terrestrial data. As a results of this study, it is verifiable that GPS surveying is very efficient to check the existing control network. 2-D network adjustment technique using GPS baseline vector is applicable to Tokyo datum without coordinate transformation. And it is expected to improve efficiency by using either rapid-static or stop and go kinematic surveying in cadastrial surveying at small areas.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2004.03a
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• pp.361-366
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• 2004

GPS 관측기법을 지적측량에 도입하기 위하여 GPS를 이용한 새로운 지적측량 모형(Model)을 정립하는 연구와 관련 기술들을 개발하는 연구가 활발히 진행되고 있다. 이와 같은 추세에 발맞추어 GPS 자료처리 및 기준점 성과산출과 관련하여 국내ㆍ외 측량 관련 상용 GPS 자료처리 소프트웨어의 현황 및 성능을 파악하고, 자료처리 알고리즘을 분석하여, 우리 실정에 적합한 GPS 자료처리 소프트웨어를 개발하는 것을 본 연구의 목적으로 한다. 본 연구에서는 국내ㆍ외의 전문 업체, 기관(대학)이 보유하고 있는 상용 소프트웨어 현황 분석 및 자료처리 방법에 따른 오차 발생을 연구하여 기선해석, 망 조정, 좌표변환 등 에 관련된 전문 소프트웨어 기능을 비교 분석하여 자료처리 산출성과의 정확도를 향상시키는 방향을 모색한다. 또한 기존 GPS 자료처리 소프트웨어에 적용된 알고리즘을 분석하고 지적측량성과 산출에 최적인 알고리즘을 연구하여 새로운 지적기준점 성과 산출을 위한 지적측량 성과계산 소프트웨어를 개발한다.