• Spatial Information Research
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• v.17 no.1
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• pp.89-102
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• 2009

The information of ocean topology is the fundamental source which is necessary for understanding the ocean, producing nautical charts and delimiting maritime boundaries. An echo sounder is being used generally to collect undersea bathymetric data, but an indirect method such as geophysical data acquired by satellites is being used recently. In this study, the outputs of ocean surveying for the production of the Basic Maps of the Sea in 1996 and 1997 in the East Sea and the bathymetric data produced by geophysical data are compared and analyzed. The study areas are Ulleung Plateau, Ulleung Basin and the southern area of Ulleung Basin which have different geophysical characteristics. Through this study, we found that the bathymetric data acquired by an indirect method using satellite is similar to the field surveying results in general configuration of ocean floor and average depth. However, the minimum square error is about 100m in 1700m depth, and it has been observed a local error up to 1000m. In addition, it has been found that the detailed undulation of ocean topology is shown on the gravity data which is acquired by the research vessel.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.1
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• pp.19-26
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• 2003

As recently, high-resolution satellite images of 1m spatial resolution are opened to the public and able to be used commercially, the studies that make ortho-images using them and apply to digital mapping and database of geo-spatial information system are having been progressed actively. Therefore, the purposes of this study are to establish the auto-extraction methods and to develope algorithms for automatically extracting buildings out of man-made structures, after making the IKONOS ortho-image. As the result of this study, we can extract buildings automatically at 72% out of the whole buildings. And we have analyzed the error trend by means of the comparison with ortho-image, digital map and drawing result, then we could know that obtain the good result for extraction of the building through the methods and algorithms of this study.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.411-416
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• 2003

다목적 대형 댐의 건설로 수몰된 과거의 삶의 공간을 20년이 지나서 다시 복원한다는 것은 그곳에 살던 실향민 등에게는 참으로 반가운 소식이다. 본 연구에서는 1980년대 초에 완공된 충주댐으로 인하여 물 속에 잠긴 청풍 지구를 수몰이전의 입체 지형 공간적으로 원형복원하기 위한 원격탐사 기법을 적용한 것이다. 비교적 해상도가 좋은 인공위성 사진자료와 원격탐지된 디지털 영상자료를 수집하고, 수몰직전에 제작된 지형도를 이용하여 위성영상자료의 통합 적용하여 수몰이전의 지형공간정보를 현재시간으로 영상 복원하는 실험을 한 것이다. 이를 위하여 지형도에서 추출한 등고선과 현재의 등고선과의 접목을 통하여 청풍 주변지역을 중심으로 당시의 수치표고모형을 생성하였다. 또한 이를 입체적으로 보여주기 위한 투시조감도를 각 방향에서 생성함으로서 수몰이전의 아름다운 모습을 3차원적으로 영상복원 하였다. 좀더 가깝게 수몰마을을 보기 위한 최근접 시뮬레이션 동영상을 제작하여 과거 기억 속의 고향을 찾아볼 수 있도록 한 것이다.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.187-193
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• 2006

With the development of technology the Global Positioning System(GPS) measurement method which uses the artificial satellites to locate its position has been adopted in construction projects. Especially in civil engineering projects which have not any base points needed to measure their position they use the GPS measurement method has been put to practical use. But it was still difficult to use that method in building construction sites which require more accurate measurement data than the current GPS measurement method can provide. In this paper we introduce a new GPS measurement method adopted in Burj Dubai project which would be the tallest building in the world after its completion.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.3
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• pp.14-24
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• 2006

There are many problems and limits in equipments being used for traffic-volume analysis in the country. And traffic-volume information acquired through existing equipments is not provided in real-time. In the case of urban, there are limits on guarantee of trust on comprehending a appropriate road-volume because of difficulty on analyzing traffic-volume density and time series. And it is difficult to applicate in deciding a road policy as existing equipments don't provide the control information of traffic-flow. Therefore, it is necessary to build a road-flow policy rapidly and accurately through the road-flow information that analyze post-processed statistics data using traffic-flow investigation based on real time. In this study, we developed TICS(Traffic Information Collection System) based on GPS which could transmit traffic information transformed from car location information to traffic control center. And we developed TCS(Traffic Control System) based on Web GIS, which could manage and analyze transmitted traffic information, and it could offer handled road-flow information to Web-site in realtime.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.15 no.2
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• pp.269-275
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• 1997

Car Navigation System with Global Positioning System (GPS) can display position direction and the shortest cut of one's destination. The position datum for GPS in World Geodetic System 1984 (WGS-84) coordinates system need to transform Bessel coordinates system and process Map projection. Since 1987, GPS has used the WGS-84. WGS-84 is a geocentric equipotential ellipsoid of revolution which is defined four parameters. In this study, by comparing the digitized topographical map with the digital map of GPS datum we can consider the technique of WGS84 digital map.

• Journal of Korean Society for Geospatial Information Science
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• v.2 no.2 s.4
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• pp.117-124
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• 1994

This paper aims at inspecting the reliability of GPS data, changing WGS 84 data into the longitude coordinates system after surveying a small number of geodetic survey or cadastre triangulation point and supplementry control point around the Kwang-Ju area, and grasping the several problems posed by introducing GPS to the cadastue or the general triangulation surveying from this time.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.1
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• pp.59-67
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• 2002

Recently, much demand of vector data have increased rapidly such as a digital map instead of traditional a paper map and the raster data such as a high-resolution orthoimage have been used for many GIS application with the advent of industrial high-resolution satellites and development of aerial optical sensor technologies. Aerial photogrammetric technologies using an airship can offer cost-effective and high-resolution color images as well as real time images, different from conventional remote sensing measurements. Also, it can acquire images easily and its processing procedure is short and simple relatively. On the other hand, it has often been used for the production of a small-scale land use map not required high accuracy, monitoring of linear infrastructure features through mosaicking strip images and construction of GIS data. Through this study, the developed aerial photogrammetric system using the airship expects to be applied to not only producing of scale 1:5, 000 digital map but also verifying, editing, and updating the digital map which was need to be reproduced. Further more, providing the various type of video-images, it expects to use many other GIS applications such as facilities management, scenery management and construction of GIS data for Urban area.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.14 no.1
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• pp.1-7
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• 1996

The idea of digital photogrammetry was first introduced into the photogrammetric community in early 1960s'. At that time, it was impossible to implement the idea due to inferior computer and digital image processing technology With the recent advancements in computer hardware/software and image processing techniques, digital photogrammetry has made its entry into the field of photogrammetry. The advent of digital photogrammetry also resulted from the increasing amount of digital data acquired through satellites, CCD cameras and digital scanning of photographs. Obviously, the major distinction between conventional photogrammetry and digital photogrammetry lies in the nature of primary input data (analogue versus digital), which could lead to a fully automated digital photogrammetric workstation. However, since digital photogrammetry is in its infant stage, virtually every task is an unsolved problem due to lack of understanding of theories and techniques. Upon considering the increasing demand of efficient digital mapping method and economical GIS database generation, the union of GIS and digital photogrammetry becomes ever clear. In this paper, the author addresses the current status of digital photogrammetry such as digital imagery and digital photogrammetric workstation as well as the role of digital photogrammetry in GIS.

• Proceedings of the KSRS Conference
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• 2008.03a
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• pp.207-212
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• 2008

연구에서는 SPOT-3 인공위성 영상으로부터 얻어진 영상 스테레오 스트립과 GCP(Ground Control Point)자료를 이용하여 다양한 GCP배치에 따른 궤도기반 센서모델의 정확성에 대해 분석하였다. 실험에 사용된 기준점자료는 춘천지역에서부터 나주지역에 이르기 까지 약 420km 길이의 지역에 대해 GPS측량을 통해 획득하였다. 궤도기반 센서모델에 적용된 미지수는 위성의 위치와 속도, 자세를 표현하는 방정식의 계수를 미지수로 선택하여 일곱 가지 방식으로 조합하였다. 실험은 우선 모델점의 위치를 일곱 가지 경우로 결정하고 각 경우에 대해 일정한 개수의 모델점을 선택하였다. 그리고 각 경우의 모델점의 위치에 대해 궤도기반 센서모델의 미지수 조합 모델을 각 각 다르게 적용해 본 후 그 결과를 시각적, 수치적으로 분석해 보았다. 실험 결과 모델점의 위치에 관계 없이 궤도기반 모델에 적용할 수 있는 높은 정확도를 나타내는 미지수 조합모델을 찾아낼 수가 있었고, 여러 가지 모델점의 위치를 궤도기반 센서모델에 적용해 본 결과 지리적, 시간적, 경제적 효율성을 갖는 최적의 미지수 조합을 찾을 수가 있었다.