• 한국군사과학기술학회지
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• 제12권1호
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• pp.80-87
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• 2009

The purpose of this study is to analyze the MAUP's effect in visibility analysis using GIS. MAUP normally occurs in the process in terrain spatial analysis including visibility analysis. There are two different types of grid data(based on digital map and Digital Terrain Elevation Data) and 10 different types of areal units are made for modeling, such as $5m{\times}5m,\;10m{\times}10m,\;15m{\times}15m,\;20m{\times}20m,\;25m{\times}25m,\;30m{\times}30m,\;35m{\times}35m,\;40m{\times}40m,\;45m{\times}45m,\;50m{\times}50$. By analyzing the result, it was possible to observe varying viewshed areas according to different grid cell sizes and the viewshed area did not varied linearly as expected. From a general point of view, smaller unit data map out the real world in more detail, but the results of modeling do not always reach a good conclusion when data are used in modeling for terrain analysis because of the MAUP' effect. The grid cell sizes of 30m or less seems to be adequate for visibility analysis, including terrain analysis considering vegetation heights.

• 한국측량학회지
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• 제27권3호
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• pp.393-400
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• 2009

최근 실세계를 재현하기 위한 3차원 기술개발의 필요성과 요구가 증가하게 되어 이러한 요구를 충족하기 위해 실세계 재현에 대한 연구가 국내외적으로 활발히 진행되고 있다. 기존에 구축된 공간분석을 위한 데이터는 2차원을 목적으로 제작되었으며 이는 3차원의 현실세계를 반영하는데 한계성이 있다. 또한 데이터 활용성이 제한적이며 데이터 재생산은 비용과 시간의 측면에서 비효율적이므로 기존의 데이터를 활용하여 효과적으로 3차원의 현실세계를 재현할 수 있는 방법에 대한 연구의 필요성이 증대되었다. DEM(Digital Elevation Model: 수치표고모델)은 활용 분야별로 다양한 요구조건을 만족하는 개별적인 방법으로 제작되어 활용되며 기존의 DEM 제작은 일률적인 보간법과 해상도로 제작되므로 데이터의 효율성이 떨어진다. 이는 실세계를 반영하기 위한 정확성에서의 한계성을 가지므로 다양한 데이터를 포함하면 효율성을 높일 수 있다. 본 연구에서는 지형분석을 통해 산악지, 구릉지, 평지로 분류 하여 서로 상이한 보간법과 해상도로 다중 해상도 DEM을 생성하였고 지형의 특성을 대표하는 model keypoint 데이터를 생성하여 포함하였다. 또한 3차원 공간정보를 포함하는 데이터 융합을 위해 도화원도와 통합하여 포괄적, 적응적 및 융통적 지형공간 데이터 모델링을 방안을 제안하였다.

• 대한공간정보학회지
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• 제5권2호
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• pp.77-85
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• 1997

컴퓨터 그래픽스 분야와 지리정보시스템 분야에서 사진과 같은 지형을 모델링하는 방법이 연구되고 있다. 이러한 지형 모델링은 비행 시뮬레이터, 임무 예행연습과 건설 계획과 같은 응용프로그램에 사용된다 지형을 표현하는 일반적인 접근방법은 수치고도모델을 사용하는 것이다. 수치고도모델이란 지형의 고도 값을 저장한 2차원 배열을 말하며 인공위성을 통해 얻어진다. 수치고도데이터를 가지고 3차원 지형을 표현하는 처리과정은 3단계로 구성되어진다. 첫 번째 단계는 수치고도 모델에서 정확도에 따라 의미점을 추출한다. 두 번째 단계는 추출된 의미점을 바탕으로 불규칙삼각망을 구성한다. 세번째 단계는 표현된 3차원 지형을 렌더링한다. 이 논문의 목적은 불규칙 삼각망을 가진 3차원 지형을 구성하는데 있다. 불규칙 삼각망의 구성을 위해 래디얼 스위프 알고리즘을 사용하였다. 래디얼 스위프 알고리즘은 불규칙 삼각망을 빠르고 효과적으로 만든다. 그러나, 불규칙 삼각망은 삼각형된 표면의 근사치에 의해 발생하는 문제를 가지고 있다. 이러한 문제를 해결하기 위해 최적화 삼각형에 의한 개선된 래디얼 스위프알고리즘을 제안한다.

• 산업기술연구
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• 제18권
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• pp.35-41
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• 1998

A watershed terrain factor is known to the very important in studies of a stream and a watershed. We have obtained the terrain factor in map directly or we have generated it in a digitalized map. In this study, DTED(Digital Terrain Elevation Data) offering in DMA(Defense Mapping Agency) was used to create a stream and a watershed and to extract the terrain factor. As comparison of the factors gererated in digitalized map the terrain factors extracted in DTED, DTED could be used to extract a terrain factor for a watershed management.

• 신재생에너지
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• 제9권2호
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• pp.15-22
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• 2013

The solar energy are an infinite source of energy and a clean energy without secondary pollution. The global solar energy reaching the earth's surface can be calculated easily according to the change of latitude, altitude, and sloped surface depending on the amount of the actual state of the atmosphere and clouds. The high-resolution solar-meteorological resource map with 1km resolution was developed in 2011 based on GWNU (Gangneung-Wonju National University) solar radiation model with complex terrain. The very high resolution solar energy map can be calculated and analyzed in Seoul and Eunpyung with topological effect using by 1km solar-meteorological resources map, respectively. Seoul DEM (Digital Elevation Model) have 10m resolution from NGII (National Geographic Information Institute) and Eunpyeong new town DSM (Digital Surface Model) have 1m spatial resolution from lidar observations. The solar energy have small differences according to the local mountainous terrain and residential area. The maximum bias have up to 20% and 16% in Seoul and Eunpyung new town, respectively. Small differences are that limited area with resolutions. As a result, the solar energy can calculate precisely using solar radiation model with topological effect by digital elevation data and its results can be used as the basis data for the photovoltaic and solar thermal generation.

• 한국지리정보학회지
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• 제4권3호
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• pp.31-40
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• 2001

지리정보체계는 도시정보체계, 토지정보체계, 시설물관리체계, 군사정보체계 등 많은 세부분야로 나누어진다. 이런 세부분야들은 서로 유기적으로 연결되어 국가지리정보체계를 이룬다. 현재 지리정보체계의 구축은 도시정보체계를 비롯하여 많은 분야에서 이루어지고 있고, 모든 분야의 정보는 서로 공유될 수 있도록 네트워크로 구축되어 있다. 현재 지적관련의 토지정보체계는 2차원에 국한되어 구축되고 있지만 지리정보체계의 연계를 통하여 3차원의 토지정보체계의 구축 및 활용이 가능하며, 이로 인한 효과는 극대화될 것으로 생각된다. 따라서 앞으로 지적도면과 다른 수치지형도와의 연결을 위한 연구가 많이 이루어져야 하며 수치도면들의 연결을 통하여 3차원 지적정보의 구축 및 분석에 대한 연구를 통한 보다 효율적인 토지정보시스템의 구축이 이루어져야 할 것이다. 본 연구는 지리정보체계 중 수치 지형도와 지적도와의 통합을 통해 3차원 수치표고모델을 구축하고, 지적정보데이터베이스와 유기적인 연결을 통한 3차원 통합 토지정보체계를 구축하는 것이 목적이다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.417-420
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• 2006

In these days, mobile application dealing with information contents on mobile or handheld devices such as mobile communicator, PDA or WAP device face the most important industrial needs. The motivation of this study is the design and implementation of mobile application using high resolution satellite imagery, large-sized image data set. Although major advantages of mobile devices are portability and mobility to users, limited system resources such as small-sized memory, slow CPU, low power and small screen size are the main obstacles to developers who should handle a large volume of geo-based 3D model. Related to this, the previous works have been concentrated on GIS-based location awareness services on mobile; however, the mobile 3D terrain model, which aims at this study, with the source data of DEM (Digital Elevation Model) and high resolution satellite imagery is not considered yet, in the other mobile systems. The main functions of 3D graphic processing or pixel pipeline in this prototype are implemented with OpenGL|ES (Embedded System) standard API (Application Programming Interface) released by Khronos group. In the developing stage, experiments to investigate optimal operation environment and good performance are carried out: TIN-based vertex generation with regular elevation data, image tiling, and image-vertex texturing, text processing of Unicode type and ASCII type.

• 대한원격탐사학회지
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• 제8권2호
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• pp.131-145
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• 1992

A low cost personal computer and image processing S/W were empolyed to derive Digtal Elevation Model(DEM) of tidal flat from multitemporal LANDSAT TM images, and to create three-dimensional(3D) perspective views of the tidel flat on Komso bay in west coasts of Korea. The method for generation of Digital Elevation Model(DEM) in tidal flat was considered by overlapping techniques of multitemporal LANDSAT TM images and interpolations. The boundary maps of tidal flat extracted from multitemporal images with different water high were digitally combined in x, y, z space with tide in formation and used as an inputcontour data to obtain an elevation model by interpolation using spline function. Elevation errors of less than $\pm$0.1m were achived using overlapping techniques and a spline interpolation approach, respectively. The derived DEM allows for the generation of a perspective grid and drape on the satellite image values to create a realistic terrain visualization model so that the tidal flat may be viewed from and desired direction. As the result of this study, we obtained elevation model of tidal flats which contribute to characterize of topography and monitoring of morphological evolution of tidal flats. Moreover, the modal generated here can be used for simulation of innudation according to tide and support other studies as a supplementary data set.

• 대한원격탐사학회지
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• 제24권5호
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• pp.497-506
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• 2008

The needs for digital models of real environment such as 3D terrain or cyber city model are increasing. Most of applications related with modeling and simulation require virtual environment constructed from geospatial information of real world in order to guarantee reliability and accuracy of the simulation. The most fundamental data for building virtual environment, terrain elevation and orthogonal imagery is acquired from optical sensor of satellite or airplane. Providing interoperable and reusable digital model is important to promote practical application of high-resolution satellite imagery. This paper presents the new research regarding representation of geospatial information, especially for 3D shape and appearance of virtual terrain. and describe framework for constructing real-time 3D model of large terrain based on high-resolution satellite imagery. It provides infrastructure of 3D simulation with geographical context. Web architecture, XML language and open protocols to build a standard based 3D terrain are presented. Details of standard-based approach for providing infrastructure of real-time 3D simulation using high-resolution satellite imagery are also presented. This work would facilitate interchange and interoperability across diverse systems and be usable by governments, industry scientists and general public.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2007년도 춘계학술발표회 논문집
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• pp.187-190
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• 2007

This study is for analyzing best band in image matching using correlation coefficient of left and right images of stereo image pair, lot red, green, blue band images separated from color aerial photo and gray image converted from the same color aerial photo image. The image matching is applied to construct Digital Elevation Model(DEM) or terrain data. The correlation coefficients and variation by change of pixel patch size are computed from pixel patches of which sizes are $11{\times}11{\sim}101{\times}101$. Consequently, the correlation coefficient in red band image is highest. The lowest is in blue band. Therefore, to construct terrain data using image matching, the red band image is preferable. As the size of pixel patch is growing, the correlation coefficient is increasing. But increasing rate declines from $51{\times}51$ image patch size and above. It is proved that the smaller pixel patch size than $51{\times}51$ is applied to construct terrain data using image matching.