• Title/Summary/Keyword: Terrain Map

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A Review of Error Detection During the Procedure of Stereo- restitution on the National Topographic Mapping in Korea (항공사진측양에서 도화작업의 오차에 대한 연구)

  • 최재화
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.4 no.2
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    • pp.43-58
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    • 1986
  • In a mapping, stereo-restitution of an aerial photogrammetric process, of which is a major factor for map-base preparation dominates the accuracy and the reliability of a topographical map. The majority of a map-base preparation has nowadays been carried out by an analogue method ie, by the stereo-plotter. In consequence, it is evident that the skilled, the level of technique and personal attitude of operator have influence upon observational error which relates the accuracy and the quality of a map. This research aims at detection and analysis of operator's carrier and types of stereoplotter. The test is also examined that the level of details and features of terrain would have influence on the accuracy of map. With the results. it is also considered that the field check has impact on map accuracy ; whether the field check prior to restitution or after restitution.

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3-D Gravity Terrain Inversion for High Resolution Gravity Survey (고정밀 중력 탐사를 위한 3차원 중력 지형 역산 기법)

  • Park, Gye-Soon;Lee, Heui-Soon;Kwon, Byung-Doo
    • Journal of the Korean earth science society
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    • v.26 no.7
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    • pp.691-697
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    • 2005
  • Recently, the development of accurate gravity-meter and GPS make it possible to obtain high resolution gravity data. Though gravity data interpretation like modeling and inversion has significantly improved, gravity data processing itself has improved very little. Conventional gravity data processing removes gravity effects due to mass and height difference between base and measurement level. But, it would be a biased density model when some or whole part of anomalous bodies exist above the base level. We attempted to make a multiquadric surface of the survey area from topography with DEM (Digital Elevation Map) data. Then we constituted rectangular blocks which reflect real topography of the survey area by the multiquadric surface. Thus, we were able to carry out 3-D inversions which include information of topography. We named this technique, 3-D Gravity Terrain Inversion (3DGTI). The model test showed that the inversion model from 3DGTI made better results than conventional methods. Furthermore, the 3-dimensional model from the 3DGTI method could maintain topography and as a result, it showed more realistic geologic model. This method was also applied on real field data in Masan-Changwon area. Granitic intrusion is an important geologic characteristic in this area. This method showed more critical geological boundaries than other conventional methods. Therefore, we concluded that in the case of various rocks and rugged terrain, this new method will make better model than convention ones.

Geospatial Data Modeling for 3D Digital Mapping (3차원 수치지도 생성을 위한 지형공간 데이터 모델링)

  • Lee, Dong-Cheon;Bae, Kyoung-Ho;Ryu, Keun-Hong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.27 no.3
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    • pp.393-400
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    • 2009
  • Recently demand for the 3D modeling technology to reconstruct real world is getting increasing. However, existing geospatial data are mainly based on the 2D space. In addition, most of the geospatial data provide geometric information only. In consequence, there are limits in various applications to utilize information from those data and to reconstruct the real world in 3D space. Therefore, it is required to develop efficient 3D mapping methodology and data for- mat to establish geospatial database. Especially digital elevation model(DEM) is one of the essential geospatial data, however, DEM provides only spatially distributed 3D coordinates of the natural and artificial surfaces. Moreover, most of DEMs are generated without considering terrain properties such as surface roughness, terrain type, spatial resolution, feature and so on. This paper suggests adaptive and flexible geospatial data format that has possibility to include various information such as terrain characteristics, multiple resolutions, interpolation methods, break line information, model keypoints, and other physical property. The study area was categorized into mountainous area, gently rolling area, and flat area by taking the terrain characteristics into account with respect to terrain roughness. Different resolutions and interpolation methods were applied to each area. Finally, a 3D digital map derived from aerial photographs was integrated with the geospatial data and visualized.

Development of 3D Terrain Tools which Improves a Picking Speed using Cross Detection (교차검출을 이용하여 Picking 속도를 향상시킨 3D 지형 툴의 개발)

  • Kim, Sung-Ho
    • The Journal of the Korea Contents Association
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    • v.12 no.2
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    • pp.78-85
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    • 2012
  • This paper proposes an efficient algorithm to develop a 3D terrain tools which is essential in the development of 3D computer games. In particular, this paper proposes a cross detection technique to improve picking speed. In other words, this paper proposes a more efficient cross detection technique consisting of a ray and a parallelogram than a cross detection technique consisting of a ray and a triangle. So, we can confirm the faster picking speed. This paper uses a picking example among DirectX SDK samples to test it. In addition, this paper compares the number of function calls for cross detection using the existing techniques and the proposed technique. As a result, in this paper the proposed technique has fallen off to about a 50 percent than the existing techniques. And if it is calculated by times, in this paper the proposed technique was reduced to 1 to 2 seconds than the existing techniques. Additionally, in this paper 3D terrain tools are provide more improved algorithms for features such as texture splatting, height map control, object arrangement and realistic water effect. So, 3D terrain tools is available efficient in the development of real 3d computer games.

Wind Farm Siting in Mountainous Terrain By Geomorphometric Characterization (지형형태 분류에 의한 산악지형 내 풍력단지 입지평가)

  • Kim, Hyun Goo;Hwang, Hyo Jung;Kang, Yong Heack;Yun, Chang Yeol;Jung, Bi Rin;Song, Kyu Bong
    • Journal of Korean Society for Geospatial Information Science
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    • v.22 no.4
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    • pp.13-19
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    • 2014
  • To develop a wind farm in a mountainous terrain like Korea, it is generally more advantageous to install wind turbines along a mountain ridge where has relatively better wind resource because that is open in all directions and free from shielding by the surrounding topography. In this study, the SRTM (Shuttle Radar Topography Mission) v4.1 3 arc-second resolution digital elevation database and the geomorphometric characterization software LandSerf v2.3 are used to extract ridge lines for assessing a wind farm siting in mountainous terrain. The effectiveness of wind farm siting along a ridge line is confirmed that the most of wind turbines in the Gangwon, Taegisan, and Maebongsan wind farms in Korea's mountainous terrain are placed along the primary and secondary ridge lines where wind resource is relatively outstanding.

A Numerical Study on the Effect of Mountainous Terrain and Turbine Arrangement on the Performance of Wind Power Generation (지형에 따른 발전기 배치가 풍력 발전 성능에 미치는 영향에 관한 수치해석 연구)

  • Lee, Myung-Sung;Lee, Seung-Ho;Hur, Nahm-Keon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.34 no.10
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    • pp.901-906
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    • 2010
  • A three-dimensional flow simulation was performed to investigate the flow field in a wind farm on a complex terrain. The present study aims to examine the effects of mountainous terrain and turbine arrangement on the performance of wind power generation. A total of 49 wind turbines was modeled in the computational domain; detailed blade shape of the turbines was considered. Frozen rotor method was used to simulate the rotating operation. The torque acting on the turbine blades was calculated to evaluate the performance of the wind turbines. The numerical results showed details of the flow structure in the wind farm including the velocity deficit in the separated flow regions; this velocity deficit was due to the topographical effect. The effect of the wake induced by the upstream turbine on the performance of the downstream wind turbine could also be observed from the results. The methodology of the present study can be used for selecting future wind-farm sites and wind-turbine locations in a selected site to ensure maximum power generation.

Development of Global Natural Vegetation Mapping System for Estimating Potential Forest Area (全球의 潛在的 森林面積을 推定하기 위한 植生圖 製作시스템 開發)

  • Cha, Gyung Soo
    • The Korean Journal of Ecology
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    • v.19 no.5
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    • pp.403-416
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    • 1996
  • Global natural vegetation mapping (GNVM) system was developed for estimating potential forest area of the globe. With input of monthly mean temperature and monthly precipitation observed at weather stations, the system spherically interpolates them into 1°×1°grid points on a blobe, converts them into vegetation types, and produces a potential vegetation map and a potenital vegetation area. The spherical interpolation was based on negative exponential function fed from the constant radius stations with oval weighing method which is latitudinally elongated weighing in temperature and longitudinally elongated weighing in precipitation. The temperature values were corrected for altitude by applying a linear lapse-rate (0.65℃ / 100m) with reference to a built-in digital terrain map of the globe. The vegetation classification was based upon Koppen’s sKDICe. The potential forest area is estimated for 6.96 Gha (46.24%) of the global land area (15.05 Gha).

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DEM Estimation Using Two Stage Stereo Matching Method (2단계 스테레오 정합기법을 이용한 DEM 추정)

  • Nam, Chang-Woo;Woo, Dong-Min
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.49 no.12
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    • pp.659-666
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    • 2000
  • A stereo matching has been an important tool for reconstructing three dimensional terrain. By using stereo matching technique, DEM(Digital Elevaton Map) can be generated by the disparity from a reference image to a target image. Generally disparity map can be evaluated by matching the reference image to the target image and if the role of the reference and the target are interchanged, a different DEM can be obtained. In this paper, we propose a new fusion technique to estimate the optimal DEM by eliminating the false DEM due to occlusion. To detect the false DEM, we utilize two measure of accuracy: self-consistency and cross-correlation score. We test the effectiveness of the proposed methods with a quantitative analysis using simulated images. Experimental result indicate that the proposed methods show 24.4% and 33.1% improvement over either DEM.

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A Local Path Planning Algorithm considering the Mobility of UGV based on the Binary Map (무인차량의 주행성능을 고려한 장애물 격자지도 기반의 지역경로계획)

  • Lee, Young-Il;Lee, Ho-Joo;Ko, Jung-Ho
    • Journal of the Korea Institute of Military Science and Technology
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    • v.13 no.2
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    • pp.171-179
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    • 2010
  • A fundamental technology of UGV(Unmanned Ground Vehicle) to perform a given mission with success in various environment is a path planning method which generates a safe and optimal path to the goal. In this paper, we suggest a local path-planning method of UGV based on the binary map using world model data which is gathered from terrain perception sensors. In specially, we present three core algorithms such as shortest path computation algorithm, path optimization algorithm and path smoothing algorithm those are used in the each composition module of LPP component. A simulation is conducted with M&S(Modeling & Simulation) system in order to verify the performance of each core algorithm and the performance of LPP component with scenarios.

Establishment of Korean Wind Map by Numerical Wind Simulation (수치바람모의에 의한 한반도 바람지도 구축)

  • Kim, Hyun-Goo;Jang, Moon-Seok;Lee, Hwa-Woon;Choi, Hyun-Jeong
    • 유체기계공업학회:학술대회논문집
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    • 2006.08a
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    • pp.265-268
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    • 2006
  • In this paper, the research background and objectives of the wind mapping project of the Korean Peninsula, which has been carrying out as a part of "Investigation of new-renewable energy resources and establishment of comprehensive management system" funded by Korea Ministry of Commerce, Industry and Energy, are introduced together with the intermediate result of the project so far. The Korean wind map is to be established by numerical wind simulation based on terrain model ME-DEM and land-use model ME-LUM with the spatial resolution of 10km.

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