• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.1
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• pp.27-36
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• 2003

Generally, the latest acquisition method of geo-spatial informations in urban area is executed by generation of digital elevation model (DEM) and digital ortho image by digital photogrammetry method which is used large scale photo image. However, the biggest problem of this method is coarse accuracy of DEM which is automatically generated by digital photogrammetry workstation system. The coarse accuracy of DEM caused geo-spatial information in urban area to reduce of accuracy. Therefore, this study is purposed to increase of DEM accuracy which is applied to method terrain classification in urban area. As the results of this study, the proposed method of this study which is increased to accuracy of DEM by classification of terrain is better than accuracy of DEM which is automatically generated by digital photogrammetry workstaion system. And, the edge detection method which is proposed by this study is established to capability of 3D digital mapping in urban area.

• Proceedings of the KSRS Conference
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• 2001.03a
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• pp.122-127
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• 2001

부산 광안리 해수욕장은 해빈유실 및 해안선이 감소하고 있다는 논란이 있는 장소이다. 그러므로, 본 연구에서는 과거 30여 년간에 항공사진과 해양조사원의 부산항 수위관측자료를 분석하여 광안리 해수욕장의 해안선변화에 관한 연구를 하였다. 매 3년마다 항공사진을 이용하여 정사투영과 DEM을 추출을 실시하였다. 그래서 광안리 해수욕장에 해안선변화가 발생하였는지, 어떠한 부분에 변화하였고, 변화한 면적은 얼마나 인가를 분석하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.5
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• pp.890-896
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• 2006

It's very difficult to acquire the accurate GCP(Ground Control Point) in the urban center and forest aerial photo because of occurring of irregular multi-path error. The purpose of this study is to apply the CPS and the EDM system for 3D orthophoto in the small areas. GCPs surveyed by accuracy triangulation from EDM after from triangulation points to a fiducial point at study area used to GPS. And I have a comment on how to use areal orthophoto for future 3D-GIS after 3D-Modelling using areal orthophoto. As the results, EDM surveying could resolve multi-path error according to GPS surveying and It is possible for using aerial orthophoto on the basis of the 3D-GIS database.

• 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.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.19 no.1
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• pp.77-83
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• 2001

To product the map by terrestrial photogrammetry method, a few rather nuisance stereo image acquiring processing and plot using expensive analytical instruments have to be performed. In this study, plot was made by acquiring and rectification image using simple method rather than above it. For this, geometry rectification system was constructed for the generation of single ortho-image analysis. and these ortho-images of architecture were made and analysed by appling various warping methods. As a result, the performance of single image analysis could be estimated, and it is expected that the application of this is possible to various non-topographic photogrammetry.

• Proceedings of the Korea Contents Association Conference
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• 2006.05a
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• pp.545-548
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• 2006

It's very difficult to acquire the accurate GCP(Ground Control Point) in the urban center and forest aerial photo because of occurring of irregular multi-path error. Thr purpose of this study is to apply the GPS and the EDM system for 3D orthophoto in the small areas. GCPs surveyed by accuracy triangulation from EDM after from triangulation points to a fiducial point at study area used to GPS. And I have a comment on how to use areal orthophoto for future 3D-GIS after 3D-Modelling using areal orthophoto. As the results, EDM surveying could resolve multi-path error according to GPS surveying and It is possible for using aerial orthophoto on the basis of the 3D-GIS database.

• Journal of Korean Society for Geospatial Information Science
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• v.10 no.3 s.21
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• pp.17-27
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• 2002

It is desirable to use a photogrammetric scanner to minimize the errors from the scanning procedure in case of building aerial photo image DB. The photogrammetric scanner, however, is highly expensive to have only limited number of scanners available, therefore the general-purpose scanners have been considered as an alternative. This study has mainly been focused to see the possibility of the general-purpose scanner to be used for scanning aerial photographs. For that, the analysis of the image coordinates were made as well as the accuracy evaluation of each phase. In addition to that, as the application of the orthophoto images has been increased, the magnitudes of the errors from the DEM generation and orthophoto projection were analyzed. Also, the calibration program was developed to verify the geometric distortion of the automatic scanner to contribute to enhance the quality of the aerial photo image DB.

• Journal of the Korean Association of Geographic Information Studies
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• v.4 no.4
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• pp.39-50
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• 2001

There has been considerable controversy over the changes in the size of the beaches in the Pusan area; any loss of beach area will have an immense effect on the tourism industry, which is an important source of income for the local economy. The best beaches in Korea are in the Pusan area and were visited by more than 8 million persons in 2000. It is expected that the number of visitors, drawn to the scenic vistas and convenient facilities of this area, will increase annually. Any loss in the size of these swimming beaches will have an important negative effect on tourism income. Therefore, the local governments have gone to great lengths to preserve these beaches, transporting tens of thousands of tons of sand to the beaches before they open each year at a cost of billions of won annually. In this study, we analyzed aerial photographs and tide data for the past 50 years using digital aerial photo analysis and GIS techniques for each 3-year interval. We abstracted beach DEM (digital elevation model) and ortho aerial photographs, and conducted a space analysis. As a result, we were able to identify changes in the area and width of sections of Haeundae Beach.

• Journal of Korean Society for Geospatial Information Science
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• v.13 no.1 s.31
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• pp.55-61
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• 2005

Digital Elevation Model (DEM) generation from remotely sensed imagery is crucial for a variety of mapping applications such as ortho-photo generation, city modeling. High resolution imaging satellites such as SPOT-5, IKONOS, QUICK-BIRD, ORBVIEW constitute an excellent source for efficient and economic generation of DEM data. However, prerequisite knowledge in the areas of sensor modeling, epipolar resampling, and image matching is required to generate DEM from these high resolution satellite imagery. From the above requirements, epipolar resampling emerges as the most important factors. Research attempts in this area are still in high demand and short supply. Another cause that adds to the complication of the problem is that most studies of DEM generation from IKONOS scenes have been based on rational function model. In this paper, we proposed a new methodology for DEM generation from satellite scenes using parallel projection model which is sensor independent, makes it possible for sensor modeling and epipolar resampling by only few control points. The performance and feasibility of the developed methodology is evaluated through real dataset captured by IKONOS.

• 한국공간정보시스템학회:학술대회논문집
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• 2005.05a
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• pp.369-374
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• 2005

정사영상 생성, 도시 공간의 모형화 등 도면화의 다양한 응용분야에 적용을 위해서는 위성 영상으로부터 수치고도모형을 생성하는 것은 중요하며, SPOT-5, IKONOS, QUICKBIRD, ORBVIEW 등의 고해상도 위성영상은 효율적이고 경제적으로 수치고도모형을 생성할 수 있는 정보를 제공하고 있다. 그러나, 이들 고해상도 위성영상으로부터 수치고도모형을 생성하기 위해서는 센서모형화, 에피폴라 영상 생성 그리고 영상정합에 대한 사전지식이 필요하다. 이들 중 에피폴라 영상생성은 중요한 인자이며 이에 대한 연구는 아직 미흡한 실정이다. 뿐만 아니라, IKONOS 위성영상으로부터 수치고도모형을 생성하는 연구는 다항식비례모형에 기반한 연구가 주로 이루어졌다. 이에 본 연구에서는 센서 독립적이면서 적은 수의 기준점만으로 센서모형화와 에피폴라 영상생성이 가능한 평행투영모형을 이용하여 수치고도모형을 생성하는 일련의 처리과정을 새롭게 제안하였다. 제안된 방법론은 IKONOS 위성영상을 이용하여 적용하고 평가하였다.