• Title/Summary/Keyword: georeference

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3D Modelling of Steep Rock Face by Terrestrial Scanning LiDAR (지상 Scanning LiDAR에 의한 암사면의 3차원 모델링)

  • Lee, Yong-Chang
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2007.04a
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    • pp.93-96
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    • 2007
  • LIDAR is a relatively new technological tool that can be used to accurately georeference terrain features, and also is becoming an important 3D mapping tool in GIS. In this study it is described the capabilities of terrestrial LIDAR that was used to build a 3D terrain model of extremely steep rock face, along with the useful data and examples of contributions terrestrial lidar has made to outcrop studies. For this, High-resolution terrestrial lidar acquisition, processing, interpretation are discussed and applied to mapping of geological surfaces in three dimensions. We expected that lidar is a tool with which we can improve our current field methods and quantify the observations geologists make.

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The Determination of Earthwork Volume using LiDAR Data (LiDAR 데이터를 이용한 토공량 산정)

  • Kang Joon-Mook;Yoon Hee-Cheon;Min Kwan-Sik;We Gwang-Jae
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2006.04a
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    • pp.533-540
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    • 2006
  • In recent years, civil-engineering work is desired the terrain information to be more efficient in earthwork volume calculation. One method for collecting elevation data is LiDAR. Lidar data was used to produce rapidly an accurate digital elevation model of the terrain, compared with the conventional ground surveys, photogrammetty, and remote sensing. Raw Lidar data is combined with GPS positional data to georeference the data sets. Lidar data is edited and processed to generate surface models, elevation models, and contours. Here we can either create a Tin Volume Surface or a Gird Volume Surface. Triangulated Irregular Network(TIN) has complex data structure, but it can describe well terrain surface features. As we have seen, we search the efficiency for earthwork volume calculation using Lidar data. One conclusion we can draw from this study is that Lidar data is more accurate result than digital map in the calculation of earthwork volume.

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Georeferencing of Primary Species Occurrence Data and Necessity of Data Quality Control - A Case Study of Two Varieties of Ox-Knee, Achyranthes bidentata Blume - (1차종발생자료를 응용한 지리참조연산표준화 및 자료 품질 관리의 필요성 - 쇠무릎과 털쇠무릎의 적용 사례 -)

  • Chang, Chin-Sung;Chang, Kae Sun;Ahn, Yong-Sup;Kim, Hui
    • Journal of Korean Society of Forest Science
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    • v.101 no.2
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    • pp.185-194
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    • 2012
  • The purpose of this contribution is to develop the framework of a methodology for identifying potential errors in georeferencing and in an application of it using specimens of Ox-Knee, Achyranthes bidentata Blume in Korea. At infraspecific level, uncertainty of identification showed that 41% of A. bidentata var. japonica and 28% of var. bidentata were misidentified, suggesting that the uncertainty level was independent of the reliability of experts' identification. For georeference specimen records, 71 specimens out of total 303 were selected and utilized as occurrence data: Uncertainty was 32.4 km at maximum and was 0.1297 km at minimum (mean = 4,055 m, s.d. = 5,772 m). Var. japonica is common throughout most of the southeastern Korea and west coastal areas, while var. bidentata has been found as far north as Gyeonggi and Gangwon provinces. We modelled the potential distribution of two varieties using Bioclim approach in Korea based on several environmental factors. Our results indicated the most important region for var. japonica lies the west coast ranges and southern area, while for Chungcheongnam-do of potential high diversity occurs for var. bidentata. This study shows that the major factors to determine the distribution patterns of two varieties were thermal factors, rather than precipitation. The Bioclim model using geocode and georeferencing data makes the information increasingly useful and reliable. To improve data quality, it requires full management from data collection to final databases including data cleaning.

A Sequential AT Algorithm based on Combined Adjustment (결합 조정에 기반한 연속 항공삼각측량 알고리즘)

  • Choi, Kyoung-Ah;Lee, Im-Pyeong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.27 no.6
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    • pp.669-678
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    • 2009
  • Real-time image georeferencing technologies are required to generate spatial information promptly from the image sequences acquired by a multi-sensor system. We thus derive a sequential adjustment algorithm based on the combined adjustment model. By adopting the sequential adjustment model, we develop a sequential AT(Aerial Triangulation) algorithm to georeference image sequences in real-time. The proposed algorithm enables to perform AT rapidly with the minimum computation at the current stage by using the results computed at the previous stage whenever a new image is added. Experiments with simulated data were conducted to verify the effectiveness of the proposed algorithm. The results of the experiments show that the georeferencing of each image took very short time and its accuracy was determined within ${\pm}4cm$ on the ground control points comparing to the results of the existing simultaneous AT.