• 농촌계획
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• 제6권2호
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• pp.43-49
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• 2000

Buffer zone selection technique for natural purification of livestock wastewater within a small agricultural watershed was developed using Geographic Information Systems. The technique was applied to $4.12\;km^2$ watershed located in Gosan-myun, Ansung-gun which have 20 livestock farmhouses. As a necessary data for selecting process, feedlot site map, digital Elevation Model (DEM), stream network, soil and land use map were prepared. By using these data, wastewater moving-path tracing program from each feedlot to the stream was developed to get the basic topographic factors; average slope through the paths, distance to the nearest stream and watershed outlet. To identify the vulnerable feedlots for storm event, the grid-based storm runoff model (Kim, 1998; Kim et al., 1998) was adopted. The result helps to narrow down the suitable area of buffer zone, and finally by using subjective but persuasive conditions related to elevation, slope and land use, the suitable buffer zones were selected.

• 한국측량학회지
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• 제24권1호
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• pp.123-130
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• 2006

본 연구에서는 기존의 수치지도를 이용한 3차원 도로설계를 이용한 방법대신에 수치지도에서 뚜렷하게 나타나지는 않는 지역을 수치사진측량방법으로 항공사진을 이용하여 DEM을 추출하여 3차원 도로설계에 적용하였다. 이를 위하여 한 쌍의 입체항공사진으로부터 수치표고모델을 생성하고 정사사진을 추출한 다음 GIS기법을 적용하여 도로설계를 위한 최적노선을 선정하였다. GIS 프로그램인 Arc View 및 MGE module 소프트웨어를 이용하여 음영기복도, 경사도. 방향도 및 지형지물의 위치도등을 결합시켜 Overlay map을 형성하여 최적노선을 선정하고 이 노선에 따라 3차원 시뮬레이션을 진행하여 그 효과를 검토하고자 하였다. 그 결과 항공사진으로부터 얻어낸 수치표고모델과 정사사진은 최적노선선정에 매우 유효하였으며, 3차원 시뮬레이션을 진행함으로서 그 효과를 충분히 확인할 수 있었다.

• 한국항공운항학회지
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• 제15권2호
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• pp.1-8
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• 2007

In this research, algorithm and software for the medium frequency signal analysis of DGPS(Differential Global Positioning System) station were developed. Based on new MF(Medium Frequency) algorithm, the software of NDGPS(National DGPS) signal analysis was developed for coverage analysis. Predicted MF propagation data from this software was compared to the measurement data for the verification of a developed MF algorithm. GIS(Geographic Information System) techniques including digital map with elevation data were used because MF propagation is closely related to ground conductivity, mountains, building intensity.

• 대한원격탐사학회지
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• 제7권1호
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• pp.13-27
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• 1991

DEM(digital elevation map) is a very useful information in various applications. In this paper, we have studied on the terrain matching algorithm using the DEM, which was proposed by Rodriguez and Aggarwal(1990) for an aircraft navigation system. We evaluated its performance using syntactic images. Cliff maps and critical points are used for the reduction of computation time and information size to be processed. The computer simulation shows that though the computational complexity is high, the technique is efficient even to noisy images.

• 한국측량학회지
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• 제35권4호
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• pp.241-248
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• 2017

GCPs (Ground Control Points) are needed to correct the DEM (Digital Elevation Model) produced from high-resolution satellite images and the RPC (Rational Polynomial Coefficient). It is difficult to acquire the GCPs through field surveys such as GPS surveys and to read the image coordinates corresponding to the GCPs. In addition, GCPs cannot cover the entire image of the test site, and the RPC correction results may be influenced by the arrangement and distribution of the GCPs in the image. Therefore, a new method for the RPC correction is needed. In this study, an LHD (Least-squares Height Difference) DEM matching method was applied using previous DEMs: SRTM DEM, digital map DEM, and corrected IKONOS DEM. This was carried out to correct the DEM produced from KOMPSAT-3 satellite images and the provided RPC without GCPs. The IKONOS DEM had the highest accuracy, and the height accuracy was about ${\pm}3m$ RMSE in a mountainous area and about ${\pm}2m$ RMSE in an area with only low heights.

• 한국지리정보학회지
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• 제10권3호
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• pp.113-122
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• 2007

최근 항공측량과 위성정보 기술의 급속한 발전은 방대한 지리정보 데이터의 신속한 취득을 가능케 하고 있다. 취득된 지리정보를 정확하게 표현하고 분석하기 위해서는 대용량 데이터를 실시간으로 시각화하는 기술을 필요로 하며, 실시간 시각화를 위해 LOD(Lovel of Detail) 알고리즘을 핵심 요소로 적용하고 있다. 본 연구는 다양한 지리정보 데이터 중 수치지형도에 포함된 등고선 데이터를 활용하여 정규화된 고도정보를 생성하는 방법으로써 TIN 생성기법을 적용하였고, 정규화 된 고도 정보를 생성하기 위해서 본 연구에서는 2단계의 작업으로 구분하여 생성하였다. 먼저 수치지형도를 활용하여 TIN 데이터를 생성하고, 생성된 TIN 데이터를 이용하여 정규화 된 고도정보를 생성하고자 하는 지역 크기의 2차원적 격자 배열을 생성하고, 격자 배열의 각 점과 생성된 불규칙 삼각망의 교차점을 구하여 정규화 된 고도정보를 생성할 수 있다. 본 연구에서는 각 단계 별로 제한된 딜로니 삼각분할(CDT, Constrained Delaunay Triangulation) 알고리즘과 생성된 TIN 데이터와 2차원적 격자 배열 각 점의 교차점을 구하기 위해 Ray-Triangle Intersection 알고리즘을 선택하였다. 또한, DirectX API 라이브러리, Quad-Tree LOD 알고리즘 그리고 프로그램 개발언어인 Microsoft Visual C++ 6.0을 이용하여 정규화된 고도정보를 3차원 지형 실시간 시각화를 통해 3차원 지형 시뮬레이션을 하였다.

• Spatial Information Research
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• 제18권5호
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• pp.63-74
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• 2010

본 연구는 비도시지역 디지털 지리정보구축 추진을 위한 중장기 기본계획안에 대한 연구를 수행하여 도출된 제도적 기반 확립을 통해, 비도시지역을 중심으로 한 디지털 지리정보구축을 토대로 전국토가 세계화 개방화 정보화 시대에 대응할 수 있도록 기초자치단체의 정보화를 강화하고자 하는데 그 목적이 있다. 중장기 계획안은 1/1,000 수치지도와 영상지도, 수치표고모형을 동시에 제작함으로써 1단계에서 디지털 지리정보 구축 및 유지관리 조직 구성, 비도시지역 공간정보인프라 구축, 관련법규 정비 및 지역협의회 구성의 기반정보를 구축하고, 2단계에서는 디지털 지리정보 구축확산, 지리정보유통 활성화, 공간데이터웨어하우스 구축, 도시계획종합관리시스템 구축 및 3차원공간정보시스템 구축의 정보화 확산 및 3단계에서는 지리정보 현행화 및 유지관리, 부가가치정보 생산, 행정업무의 고도화 및 대민서비스 극대화를 통한 정보 고도화를 실현함으로써 시군구/시도/중앙정부의 통합지리정보의 기반이 되는 지리정보를 구축 방안을 제시하고자 한다.

• 대한전기학회논문지:시스템및제어부문D
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• 제50권5호
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• pp.226-232
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• 2001

The ability to efficiently and robustly recover accurate 3D terrain models from sets of stereoscopic images is important to many civilian and military applications. To develop an effective and practical terrain modeling system, we propose a new multi-image stereo method which detect unreliable elevations in DEM(Digital Elevation Map), and fuse several DEMs from multiple sources into an accurate and reliable results. This paper focuses on two key factors for generating robust 3D terrain models: the ability to detect unreliable elevation estimates and the ability to fuse the reliable elevations into a single optimal terrain model. We apply the self-consistency methodology to reconstruct accurate DEM from multi-image and show the method is more effective than the conventional stereo image 3D reconstruction method. Using photo-realistic simulator, four synthetic image are generated from ground truth DEM and orthoimage to evaluate the accuracy of the proposed method quantitatively.

• Journal of Platform Technology
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• 제11권4호
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• pp.13-18
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• 2023

3D content rendering is one of the important factors that give a sense of realism when creating content, and this process takes a lot of time. In this paper, we proposed a method to improve rendering performance by reducing the vast amount of 3D data in the web environment, and conducted a performance test using DEM and 3D model elevation data. As a result of the experiment, the digital elevation model showed faster performance than the Blender-based 3D modeling, but when the screen was moved using OrbitControl, the fps dropped momentarily. In the case of Terrain, if the range is limited to a speed that maintains 24 to 60 fps using frustum culling and LOD techniques, it is considered that a higher quality map can be produced than GeoTIFF.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 1999년도 Proceedings of International Symposium on Remote Sensing
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• pp.343-348
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• 1999

Delineation of watersheds is one of the most basic steps for water resource management and National Park management. The purpose of this study is to investigate how to utilize Thematic Mappers scenes to compare watersheds created by running a model with those produced by digitizing topographic maps of Keum River basin. A methodology is designed and tested using Geographic Information Systems (GIS) and remote sensing to map areas with various thematic maps. A CAD data on watersheds from the Decision Support system for Water Quality is converted into GIS format. The digital elevation model with 100-meter resolution is used to create watershed by cumulative watershed method. TM scenes are also classified by new procedures including stacking method, NDVI, NDWI, and unsupervised classification methods. To evaluate the relative correctness Kyerongsan National Park was studied intensively whose area was divided into 6 watersheds in both cases. The boundaries of watershed from the model are less correct than those of the topographic maps. This result shows that automated watershed creating system needs higher-resolution digital elevation model than 100-meters.