• 한국측량학회지
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• 제28권3호
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• pp.337-345
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• 2010

일반적으로 비용이 많이 들고 복잡한 처리과정을 거치는 디지털 항공사진측량은 독립형 워크스테이션 시스템을 기반으로 사용되어 왔다. 본 연구에서는 Open Geospatial Consortium에서 제안한 국제 GIS 표준인 Web Processing Service을 통해 항공사진측량 처리 과정에 대한 새로운 접근 방안을 제시하고자 한다. 실험을 위해 항공사진측량 업무를 기본단위로 정의하는 WPS 프로파일링 과정을 거쳐 여러 개의 제네릭 프로세스로 정의하였고, 정의된 프로세스는 WPS 표준에 따라 각각 서버 S/W와 클라이언트 S/W 모듈을 구현하였다. 본 연구를 통해 WPS의 기본 단위 항공사진측량 프로세스를 다수의 사용자가 웹을 사용하여 공유, 재활용 측면의 접근을 기대할 수 있었다.

• 한국측량학회지
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• 제32권4_1호
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• pp.293-298
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• 2014

최근의 항공사진측량은 디지털항공사진 카메라와 GPS/ INS를 결합한 통합 센서를 활용하여 Direct Georeferencing 하는 방법이 보편화됐으며, 이를 기반으로 신속하고 정확하게 사진측량을 수행할 수 있게 되었다. Direct Georeferencing을 통해 얻을 수 있는 외부표정요소의 정확도는 GPS/INS에 의해 결정되는데, INS의 회전량 차이를 결정하여 자세정보를 정확하게 계산하는 것이 중요하다. 이를 위해 Boresight Calibration으로 INS의 회전량 차이 및 GPS와 INS 간의 간격과 같은 Misalignment를 결정해야 한다. 이때 많은 수의 지상기준점을 이용하여 항공삼각측량과 Boresight Calibraiton을 하게 되는데, 지상기준점의 수와 배열, 위치에 따라 그 결과가 다르게 나타난다. 연구 결과 모든 사진코스에 지상기준점을 배치할 경우 점수의 변화에 따른 Misalignment와 외부표정요소는 큰 변화가 없었으나 지상기준점이 없는 코스가 있을 경우 그 값들에서 차이가 크게 발생하였다.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2003년도 춘계학술발표회 논문집
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• pp.471-477
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• 2003

This paper presents an algorithm that automatically extracts buildings among many different features on the earth surface by fusing LIDAR data with panchromatic aerial images. The proposed algorithm consists of three stages such as point level process, polygon level process, parameter space level process. At the first stage, we eliminate gross errors and apply a local maxima filter to detect building candidate points from the raw laser scanning data. After then, a grouping procedure is performed for segmenting raw LIDAR data and the segmented LIDAR data is polygonized by the encasing polygon algorithm developed in the research. At the second stage, we eliminate non-building polygons using several constraints such as area and circularity. At the last stage, all the polygons generated at the second stage are projected onto the aerial stereo images through collinearity condition equations. Finally, we fuse the projected encasing polygons with edges detected by image processing for refining the building segments. The experimental results showed that the RMSEs of building corners in X, Y and Z were ${\pm}$8.1cm, ${\pm}$24.7cm, ${\pm}$35.9cm, respectively.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2003년도 추계학술발표회 논문집
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• pp.147-152
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• 2003

Aerial Images are usually used to extract 3-D coordinates of various urban features. In this process, the stereo matching of images should be performed precisely to extract these information from aerial Images. In this research, we proposed a matching technique based on geometric features of lanes. We extracted lanes from aerial images and grouped into 4 lane's types. They are lane lines, dotted lines, arrow lane, safety zone. After preprocessing, We will match them by spatial relationships, for example, the distance and orientation between the extracted features. In the future, we will obtain lane coordinates and reconstruct 3-d coordinates of roads.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2003년도 추계학술발표회 논문집
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• pp.225-230
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• 2003

Efficient representation is crucial in the analysis of complex geospatial information. In case of aerial triangulation, most of currently available software are designed as black boxes where only an experienced user would be able to prepares the preformatted input file and interprete the result of the adjustment. This paper introduces a solution to this problem through the UML design of a Graphical User Interface (GUI) for the aerial triangulation task. The design was then implemented with ArcGIS. The error of the exterior orientation of each aerial Imagery was represented with a 3-D error ellipse, enabling the visualization of the adjustment result. The attributes of images and points (control points, tie points and image points) were maintained as a database which enables the searching and querying of adjustment information.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2003년도 추계학술발표회 논문집
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• pp.141-146
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• 2003

In case of producing image map by using the color aerial photograph, DEM makes on huge effects to the accuracy of ortho image. Thus, this paper has the purpose that evaluate the accuracy of DEM acquired by matching the color aerial photograph. At the study, result of color aerial photograph's control point surveying was X=${\pm}$0.14m, f=${\pm}$0.16m. Estimated result by DEM of plot-map and matching has RMSE=${\pm}$1.058m for the elevation(Z). For matching DEM has a minor(-)'s value, it can access that produce by high point than plot-map DEM.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 춘계학술발표회논문집
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• pp.553-558
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• 2004

Periodic profiling by level is a conventional method for monitoring topographic changes in a specific part of tidal zone. Periodic aerial photographs are used for monitoring topographic change of broad tidal zone area. In this study, spot heights at interval of 50m on 5 profiling lines were leveled periodically for precise monitoring topographic change of tidal zone. For monitoring broad topographic change of tidal zone, aerial photographs were also taken by film camera loaded on pilotless helicopter periodically Periodic profiling shows the change of heights on the lines well. On the other hand, aerial photographs taken by film camera loaded on pilotless helicopter have some problems to detect topographic change of tidal zone precise. Because the scale and incline of the photographs were not same, it is hard to compare them. Therefore, for more precise monitoring of topographic changes in tidal zone, it is need to take aerial pictures with same scale and same incline.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2006년도 춘계학술발표회 논문집
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• pp.217-222
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• 2006

In this study, we performed three dimensional(3-D) modeling and simulation of terrain surfaces by using large scale aerial photographs. The objectives of this study are to use landscape analysis including 3-D database of built environments. The test area is selected around Olympic stadium located in Susung-gu, Daegu. A 1:5,000 scale of ortho-photo map is generated by photogrammetric procedures from 1:20,000 scale of aerial photographs, Digital Elevation Model (DEM) is also extracted from stereo aerial photographs or digital maps. The heights of buildings are determined using GPS control survey and aerial photographs in the test area, DEMs are extracted from the digital map. And then the two are combined three-dimensional changes of landscape views of buildings with terrain are simulated.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 추계학술발표회 논문집
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• pp.239-243
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• 2004

Recently various thematic maps and image maps using aerial photograph and satellite imagery are frequently made. The geo-referencing is essential to make image map and topographic map using aerial photograph and satellite imagery. For this geo-referencing, Ground Control Points (GCPs) are needed. In this paper, we used GPS relative positioning to measure GCP ground coordinate and the accuracy of 8cm level was achieved. We made GCP image chips for the efficiency of geo-referencing and carried out the bundle adjustment of aerial photographs using GCP image chips to acquire the GCP photo coordinate with image matching technique. Finally we analyzed the accuracy of bundle adjustment compared to the accuracy of the case in using digital maps to acquire GCP photo coordinate.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 Korea-Russia Joint Conference on Geometics
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• pp.64-72
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• 2004

Correction of shadow effects is critical step for image interpretation and feature extraction from aerial imagery. In this paper, an efficient algorithm to correct shadow effects from aerial color imagery is presented. The following steps have been performed to remove the shadow effect. First, the shadow regions are precisely located using the solar position and the height of ground objects derived from LIDAR (Light Detection and Ranging) data. Subsequently, segmentation of context regions is implemented for accurate correction with existing digital map. Next step, to calculate correction factor the comparison between the context region and the same non-shadowed context region is made. Finally, corrected image is generated by correcting the shadow effect. The result presented here helps to accurately extract and interpret geo-spatial information from aerial color imagery