• Journal of Korean Society for Geospatial Information Science
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• v.17 no.1
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• pp.21-35
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• 2009

KOMPSAT-2 is the seventh high-resolution image satellite in the world that provides both 1m-grade panchromatic images of the GSD and 4m-grade multispectral images of the GSD. It's anticipated to be used across many different areas including mapping, territory monitoring and environmental watch. However, due to the complexity and security concern involved with the use of the MSC, the use of KOMPSAT-2 images are limited in terms of geometric images, such as satellite orbits and detailed mapping information. Therefore, this study aims to produce DEM and orthoimage by using the stereo images of KOMPSAT-2, and to explore the applicability of geo-spatial information with KOMPSAT -2. Orientation interpretations were essential for the production of DEM and orthoimage using KOMPSAT-2 images. In the study, they are performed by utilizing both RPC and GCP. In this study, the orientation interpretations are followed by the generation of DEM and orthoimage, and the analysis of their accuracy based on a 1:5,000 digital map. The accuracy analysis of DEM is performed and the results indicate that their altitudes are, in general, higher than those obtained from the digital map. The altitude discrepancies on plains, hills and mountains are calculated as 1.8m, 7.2m, and 11.9m, respectively. In this study, the mean differences between horizontal position between the orthoimage data and the digital map data are found to be ${\pm}3.081m$, which is in the range of ${\pm}3.5m$, within the permitted limit of a 1:5,000 digital map. KOMPSAT-2 images are used to produce DEM and orthoimage in this research. The results suggest that DEM can be adequately used to produce digital maps under 1:5,000 scale.

• Proceedings of the Korea Contents Association Conference
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• 2014.11a
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• pp.65-66
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• 2014

좁은지역에 대한 지형정보의 획득은 저고도 UAV시스템을 이용하는 것이 경제적이다. 최근 자동항법 UAV의 발전은 저고도 고해상도 영상을 원하는 주기로 얻을 수 있어 많은 분야에 응용하고 있다. 이러한 UAV시스템은 지상관제센터와 비행체 간의 긴밀한 통신이 이루어져야 하며 촬영 중 영상의 획득 여부를 모니터링할 수 있어야 한다. 본 연구에서는 NASA가 개발한 Worldwind를 커스터마이징하여 실시간 영상획득 모니터링 s/w를 개발하였다. 또한 개발시스템을 이용하여 정사영상 모자익을 실시하였으며 이에대한 정확도 분석을 실시하였다. 분석결과 검사점에 대해 정사모자익영상의 수평위치 정확도를 분석한 결과 X좌표에서 평균 0.181m, Y좌표에서 평균 0.203m의 편차를 보임으로써 1:1,000~5,000축척의 수치지도제작이 가능할 것으로 판단된다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.3
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• pp.313-321
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• 2002

Supplying high-resolution satellite image, we take much interest in the update and the revision of digital map and thematic map based on the satellite image. This study presented the possibility of the update and the revision to the existing digital map on a scale of l/5,000 and 1/25,000 to take advantage of the IKONOS satellite image. We performed geometric correction to make use of the ground control points of the existing digital map in IKONOS mono-image and created ortho-image by extracting digital elevation model from three dimensional contour data and altitude on the existing digital map. We revised changed features in the method of screen digitizing by overlapping orthorectified satellite image and existing digital map and flawed features of the unchanged area on the satellite images for positional accuracy analysis. As a result, rectification error is calculated at $\pm$3.35m by RMSE. There is a good possibility of update of digital map under the scale of 1/10,000. It is possible to the update of the large scale digital map over the scale of l/5,000, as if we used the method of stereo image and ground control point surveying.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.19 no.3
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• pp.219-228
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• 2001

The research into the field of managing urban utility information (such as gas pipes, power line, telecommunication utilities) is growing ever more important as the efficient management of social infra-structure gets higher and also with the fast technological progress made in nationwide scale of geo-spatial information systems. This research is focused on the collection of street utilities information in urban areas using aerial ortho-images. Until now this has been carried out by on site investigation and ground surveying methods. The result of this research shows that the geometric accuracy was obtainable within 12 cm referenced to 1/1,000 digital map. It was also possible to collect the street utilities which were described in the digital map as well as other information which were not.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2006.05a
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• pp.122-126
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• 2006

입체영상 획득이 가능한 SPOT 위성이 발사되면서 위성영상을 이용한 지도제작 둥의 정량적인 분석이 가능해졌다. 특히, 고해상도 위성영상은 항공사진촬영이 불가능하여 대축척 지도제작이 곤란한 지역 또는 지상기준점 측량이 불가능한 지역에 대한 수치지도 제작 분야에 있어 효율적인 방법으로 주목을 받고 있다. 이에 본 연구에서는 기 접근 가능지역에 대한 정사영상을 이용하여 기 구축된 성과들의 정확도를 평가하였고 이를 바탕으로 비접근지역의 지형정보 획득을 위한 정사영상의 활용 가능성을 제시하고자 하였으며 비접근 및 난접근 지역에서의 지상기준점 획득에 대한 제한을 극복하는 수단으로 본 연구의 결과를 활용하고자 하였다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.3
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• pp.155-166
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• 2017

As the utilization of aerial images increases, a variety of software using unmanned aerial photogrammetric procedures as well as traditional aerial photogrammetric procedures are being provided. Previously, software that used the unmanned aerial photogrammetric procedure was used for images captured in small areas. Recently, however, software that uses unmanned aerial photogrammetric procedures for large-scale images taken by using aerial photogrammetric cameras has appeared. Therefore, this study generated ortho-images using aerial photogrammetry and unmanned aerial photogrammetry for large aerial images, and compared the features of both procedures through qualitative and quantitative comparisons. Experiments in the study area show that using the 3D mesh effectively removes the relief displacement of the building rather than using the digital surface model to generate ortho-images.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.3
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• pp.283-290
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• 2016

Even though existing methods for orthophoto production in traditional photogrammetry are effective in large areas, they are inefficient when dealing with change detection of geometric features and image production for short time periods in small areas. In recent years, the UAV (Unmanned Aerial Vehicle), equipped with various sensors, is rapidly developing and has been implemented in various ways throughout the geospatial information field. The data and imagery of specific areas can be quickly acquired by UAVs at low costs and with frequent updates. Furthermore, the redundancy of geospatial information data can be minimized in the UAV-based orthophoto generation. In this paper, the orthophoto and DEM (Digital Elevation Model) are generated using a standard low-end UAV in small sloped areas which have a rather low accuracy compared to flat areas. The RMSE of the check points is σ_H = ±0.12 m on a horizontal plane and σ_V = ±0.09 m on a vertical plane. As a result, the maximum and mean RMSE are in accordance with the working rule agreement for the airborne laser scanning surveying of the NGII (National Geographic Information Institute) on a 1/500 scale digital map. Through this study, we verify the possibilities of the orthophoto generation in small slope areas using general-purpose low specification UAV rather than a high cost surveying UAV.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.513-518
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• 2004

본 연구에서는 수변구역의 효율적인 관리를 위하여 토지에 대한 자연적인 형상을 나타내는 수치정사 영상과 필지를 중심으로 토지에 대한 물리적 현황 및 소유권이 미치는 범위를 나타내는 지적도면을 중첩한 수치정사영상지적도의 제작방법의 효율성을 모색하였다. 이를 통하여 수변구역 경계관리를 위하여 작성된 수치정사영상지적도는 수변구역의 경계관리 목적 이외에도 다양한 분야에서 매우 광범위하게 활용될 수 있을 것으로 기대된다. 또한 향후 지적재조사사업 시행시 임야 및 농경지의 경계를 새로이 설정할 경우 경제적이고 시각적이며 활용적인 측면에서 매우 효과적인 방법임을 확인할 수 있다.

• 한국지형공간정보학회:학술대회논문집
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• 2002.11a
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• pp.81-92
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• 2002

일반적으로 수치사진측량시스템을 통해 도심지역에서 자동으로 DEM을 추출하는 경우 해석도화원도에서 추출하는 DEM에 비하여 정확도가 크게 저하되어 도심지역에 대한 정사투영영상 생성이나 정사투영영상을 이용한 수치지도 제작시 품질저하의 요인이 되고 있다. 따라서 본 연구는 수치사진측량기법을 이용한 도심지역 지형공간정보 생성시 정확도에 영향을 크게 미치는 도심지역 DEM의 정확도를 향상시키는데 목적이 있다. 본 논문의 수행결과, 수치사진측량기법을 이용하여 도심지역에 대한 DEM 추출시 대상지역에 대한 지형분류를 통한 DEM추출방법을 적용하여 도심지역에 대한 DEM의 정확도를 향상시킬 수 있었다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3D
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• pp.417-422
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• 2008

With standard orthorectification algorithms, one can produce unacceptable structure duplication in the orthophoto due to the double projection. Because of the abrupt height differences, such structure duplication is a frequently occurred phenomenon in the dense urban area which includes multi-history buildings. Therefore, occlusion area detection especially for the urban area is a critical issue in generation of true orthophoto. This paper deals with occlusion area detection with visible height based approach from aerial imagery and LiDAR. In order to accomplish this, a grid format DSM is produced from the point clouds of LiDAR. Next, visible height based algorithm is proposed to detect the occlusion area for each camera exposure station with DSM. Finally, generation of true orthophoto is presented with DSM and previously produced occlusion maps. The proposed algorithms are applied in the Purdue campus, Indiana, USA.