• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.18 no.1
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• pp.1-9
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• 2000

In the recent day, the necessity and the effective usage are increased rapidly, and it is applied in many other fields as well as in the field of ortho-photo map. In this study, we extract each objects on the aerial image and automatically classify graphic information to produce digital map using only digital ortho-image without particular drawing devices for producing digital map. For this purpose, we have applied a lot of the image processing techniques and fuzzy theory, classified outline and lane of road and building, and had each layer according to each feature. Especially, in the case of the building, the outer vector lines extracted by pixel unit at the building were very complex, but we have developed the program to be expressed by I-dimensional linear type between building corners. In the result of this study, we could not extract and recognize all of the object on the image all together, but we have got the error within 50cm using semi-automatic technique. Therefore, this method will be used effectively in producing 1/5,000 digital map.

• Journal of Cadastre & Land InformatiX
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• v.51 no.1
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• pp.125-136
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• 2021

Recently, Unmanned Aerial Vehicle utilization and image processing technology for remote sensing have diversified remarkably with Orthophoto and Digital Surface Model. In particular, It uses more application fields such as spatial information analysis and hazardous areas as well as land surveying. This study analyses the accuracy of the coordinate on Orthophoto and DSM height on slope area with high and low differences by using UAV images. As the result of this study, in the case of GCP on 2D orthophoto, the location error was not produced significantly. The vertical position of the DSM showed the highest accuracy when the height difference between GCPs is under 30m(RMSEZ=0.07m). The location of the GCPs was divided into approximately 10m, 20m, 30m, and 40m with analysis for each of the eight points of GCP and inspection points in general. This study expects that producing both horizontal accuracy of Orthophoto and vertical accuracy of DSM using UAV on the sloped area which similar to this research area will help in spatial information fields.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.1
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• pp.80-89
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• 2008

Mapping applications using satellite imagery have been possible to quantitative analysis since SPOT satellite with stereo image was launched. Especially, high resolution satellite imagery was efficiently used in the field of digital mapping for the areas which are difficult to produce large-scale maps by aerial photogrammetry or carry out ground control point surveying due to unaccessibility. This study extracted the geospatial information out of consideration for topographic characteristic from ortho imagery of the National Geospatial-intelligence Agency(NGA) in the United States of America and analyzed the accuracy of plane coordinate for ortho imagery. For this purpose, the accuracy according to topographic character by comparison between both extraction data from ortho imagery and the digital topographic maps of 1:5000 scale which were produced by Korea National Geographic Information Institute(NGI) was evaluated. It is expected that the results of this study will be fully used as basic information for ground control point acquisition or digital mapping in unaccessible area.

• 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.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.5
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• pp.535-544
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• 2016

Even though existing methods for orthophoto production using expensive aircraft are effective in large areas, they are drawbacks when dealing with renew quickly according to geographic features. But, as UAV(Unmanned Aerial Vehicle) technology has advanced rapidly, and also by loading sensors such as GPS and IMU, they are evaluates that these UAV and sensor technology can substitute expensive traditional aerial photogrammetry. Orthophoto production by using UAV has advantages that spatial information of small area can be updated quickly. But in the case of existing researches, images of same altitude are used in orthophoto generation, they are drawbacks about repetition of data and renewal of data. In this study, we targeted about small slope area, and by using low-end UAV, generated orthophoto and DEM(Digital Elevation Model) through different altitudinal images. The RMSE of the check points is σ_h = 0.023m on a horizontal plane and σ_v = 0.049m on a vertical plane. This maximum value and mean RMSE are in accordance with the working rule agreement for the aerial photogrammetry of the National Geographic Information Institute(NGII) on a 1/500 scale digital map. This paper suggests that generate orthophoto of high accuracy using a different altitude images. Reducing the repetition of data through images of different altitude and provide the informations about the spatial information quickly.

• Proceedings of the KSRS Conference
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• 2006.03a
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• pp.19-23
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• 2006

본 연구는 컬러항공사진을 이용하여 컬러영상, 그레이영상 그리고 각 밴드별(RGB) 수치고도모형(DEM)을 생성하여 정확도를 평가하기 위한 것이다. 항공 영상지도의 경우 불과 4-5년 전까지만 해도 흑백항공사진 필름을 이용해 왔으나 최근 들어 판독을 더욱 용이하게 하기 위하여 컬러항공사진을 많이 이용하고 있다. 품질이 높은 정사영상제작을 위해서는 정확한 수치고도모형이 필요하다. 수치고도모형을 생성하기 위한 대표적인 방법으로 수치지도를 이용하는 방법과 영상정합기법을 이용하여 수치고도모형을 생성할 수 있다. 영상정합기법에 의한 수치고도모형 생성 방법은 흑백항공사진에서와는 달리 컬러항공사진은 항공사진 전용 스캐너에서 3개의 밴드(RGB)로 스캔된 영상을 사용한다. 본 연구에서는 수치고도모형의 정확도를 분석하기 위하여 모두 5가지 영상(컬러영상, 그레이영상, Red 영상, Green 영상, Blue 영상)을 획득하였으며 각 밴드별 수치고도모형을 생성하여 수치지도에서 추출된 표고점 자료와의 평균제곱근오차(RMSE) 값을 비교하였다. 본 연구에서는 Red 영상을 이용하는 경우 가장 정확한 수치고도모형을 얻을 수 있었음을 실험을 통해 검증하였다.

• Proceedings of the Korea Contents Association Conference
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• 2005.05a
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• pp.138-141
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• 2005

본 연구에서는 위성영상으로부터 정사투영 영상을 제작하고, 지상의 기준점 측량을 GCP를 이용하여 실시하여 경도, 위도 고도의 참조좌표를 정확히 수집하였다. 1:5,000 지형도를 디지타이징하여 만들어진 등고선도를 DEM으로 변환하여 고도별 RGB영상으로 화면에 보여지도록 하고, 각각의 경우에 대하여 제작된 정사투영 영상에 중첩해 봄으로써 제작된 정사투영영상의 정확도를 점검하여 수치지형도를 대신할 수 있는 3차원 영상지도를 제작하였다. 대상지역의 입체지형분석을 위한 3차원 입체 영상지도를 제작과 더불어 DEM을 이용한 지형의 경사도 분석과 방향분석, 지형표고모델, 다방향 입체영상을 생성할 수 있도록 하였다. 장차 국토계획 및 건설분야에서의 지형분석과 각종 구조물의 배치 및 관리, 하천 수계의 분포에 대한 댐 건설 최적지 선정, 도로계획선에 따른 각 방향의 조감도 제작, 토지 피복분류에 의한 토지이용과 지역개발계획 등 지역환경을 종합적으로 진단해 볼 수 있는 활용방안을 도출할 수 있는 적용실험을 하였다.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2002.10a
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• pp.103-106
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• 2002

본 연구에서는 항공사진에 의한 해안선변형을 해석함에 있어서 수치정사영상 방법과 affine 변환을 이용하여 해안선변형을 분석하고, 두 가지 방법에 대한 정확도를 평가함으로써 항공사진을 이용한 해안선변형 해석의 보다 효율적인 방법을 제안하고자 하였다. 검토결과 정확도 평가 분석에서 알 수 있듯이 수치정사영상의 경우 RMS 오차가 3∼5m 정도로 나타났으며, affine 변환의 경우는 RMS 오차가 5∼8m정도인 것을 확인할 수 있었다. 정확도 평가에서 나타난 RMS 오차는 비록 수치정사영상을 이용한 해석방법보다는 정확도 면에서 약간의 차이가 발생하나 이때의 오차가 2∼3m 정도인 것으로 미루어 볼 때 affine 변환을 이용한 해석방법도 매우 정도가 높은 것이라 사료된다. 아울러, 수치정사영상의 경우 그 과정이 매우 복잡하고 어려운 점을 감안하면 affine 변환에 의한 해석방법이 항공사진을 이용한 해안선변형 해석을 수행함에 있어서 매우 효과적인 방법이라 사료된다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.14 no.2
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• pp.189-197
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• 1996

Digital Elevation Model, Ortho-image, and 3-D positional data of terrain features are indispensable elements for producing 3-D image information. In this research, digital pbotogrammetric studies were conducted to measure the 3-D positional data on high performance computer systems in order to replace analytical stereo-plotter-oriented tasks with those of digital workstations. Especially, technical approaches to measure these data on stereo workstation were developed and then the results were applied on SPOT satellite images. As the result of this study, the possibilities of the proposed technologies were tested and proved based on the ap-plication of the digital photogrammetric processes to extract 3-D ground coordinates of terrain features from digital satellite imagery.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.04a
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• pp.259-262
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• 2004

There is the case to make the image map by using color aerial photo, DEM gives the accuracy of the Ortho image. Therefore We evaluate the accuracy by digital photogrammetric system after generating the DEM of Color Aerial Image.