• Proceedings of the Korea Contents Association Conference
• /
• 2007.11a
• /
• pp.27-29
• /
• 2007

The visual implementation of 3-dimensional national environment is focused by the requirement and importance in the fields such as, national development plan, telecommunication facility deployment plan, railway construction, construction engineering, spatial city development, safety and disaster prevention engineering. The currently used DEM system using contour lines, which embodies national geographic information based on the 2-D digital maps and facility information has limitation in implementation in reproducing the 3-D spatial city. Moreover, this method often neglects the altitude of the rail way infrastructure which has narrow width and long length. There it is needed to apply laser measurement technique in the spatial target object to obtain accuracy. Currently, the LiDAR data which combines the laser measurement skill and GPS has been introduced to obtain high resolution accuracy in the altitude measurement. In this paper, we first investigate the LiDAR based researches in advanced foreign countries, then we propose data a generation scheme and an algorithm for the optimal manage and synthesis of railway facility system in our 3-D spatial terrain information. For this object, LiDAR based height data transformed to DEM, and the realtime unification of the vector via digital image mapping and raster via exactness evaluation is transformed to make it possible to trace the model of generated 3-dimensional railway model with long distance for 3D tract model generation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.38 no.4
• /
• pp.345-352
• /
• 2020

To preserve and restore tidal flats and prevent safety accidents, it is necessary to construct tidal flat topographic information including the exact location and shape of tidal creeks. In the tidal flats where the field surveying is difficult to apply, airborne LiDAR surveying can provide accurate terrain data for a wide area. On the other hand, we can economically obtain relatively high-resolution data from UAV (Unmanned Aerial Vehicle) surveying. In this study, we proposed the methodology to generate high-resolution topographic information of tidal flats effectively by integrating airborne LiDAR and UAV point clouds. For the purpose, automatic ICP (Iterative Closest Points) registration between two different datasets was conducted and tidal creeks were extracted by applying CSF (Cloth Simulation Filtering) algorithm. Then, we integrated high-density UAV data for tidal creeks and airborne LiDAR data for flat grounds. DEM (Digital Elevation Model) and tidal flat area and depth were generated from the integrated data to construct high-resolution topographic information for large-scale tidal flat map creation. As a result, UAV data was registered without GCP (Ground Control Point), and integrated data including detailed topographic information of tidal creeks with a relatively small data size was generated.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.28 no.3
• /
• pp.385-392
• /
• 2010

A LiDAR technique has the merits that survey engineers can get a large number of measurements with high precision quickly. Aerial photos and satellite sensor images are used for generating 3D spatial images which are matched with the map coordinates and elevation data from digital topographic files. Also, those images are used for matching with 3D spatial image contents through perspective view condition composed along to the designated roads until arrival the corresponding location. Recently, 3D aviation image could be generated by various digital data. The advanced geographical methods for guidance of the destination road are experimented under the GIS environments. More information and access designated are guided by the multimedia contents on internet or from the public tour information desk using the simulation images. The height data based on LiDAR is transformed into DEM, and the real time unification of the vector via digital image mapping and raster via extract evaluation are transformed to trace the generated model of 3-dimensional downtown building along to the long distance for 3D tract model generation.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.6 no.3
• /
• pp.95-106
• /
• 2003

This study evaluated the architectural density of urban district using airborne laser scanning(ALS) that is a method used in urban planning, water resources and disaster prevention with high interest recently. First, digital elevation model(DEM) and digital surface model(DSM) was constructed from Light detection and ranging(LiDAR). For getting the height of building, ZONALMEAN filter was used in DEM and ZONALMAJORITY filter was used in DSM. This study compared the floor from filtering with the floor from survey and got standard error, which is ${\pm}0.199$ floor. Also, through the overlay and statistical analysis of total-area layer and zone layer, we could present floor area ratio by zone. As a result of comparison with floor area ratio between airborne laser scanning data and survey data, the standard error of floor area ratio shows ${\pm}2.68%$. Therefore, we expect that airborne laser scanning data can be a very efficient source to decision makers who set up landuse plan in near future.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.13 no.4
• /
• pp.50-66
• /
• 2010

In this study, we performed a GIS-based debris flow simulation using the high-resolution airborne LiDAR DEM in order to establish the effective and resonable debris prevention plans in Korea. To do so, we set a study area to an specific region over Pyeochang-gun in Kangwon-do which showed the extreme rugged distribution of topography and simulated a possibility of debris flow occurrence in this area using a GIS-based numerical simulation program which was developed by applying the finite difference method. After that, we also performed the debris flow simulation by SINMAP and geomorphic analysis method in the same region and compared each result with that of GIS-based debris simulation for verifying the reliability.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2019.05a
• /
• pp.262-262
• /
• 2019

2011년 7월 27일 서울 지역에 내린 시간당 100mm가 넘는 집중호우로 우면산 일대에 산사태가 발생하였고, 그 결과 많은 인명과 재산 피해가 야기되었다. 이러한 토석류로 인한 피해를 저감하기 위한 여러 연구가 이루어진 바 있으나, 대부분의 연구는 연행작용에 대해서 고려하지 못하고 있거나, 인명과 재산 피해의 큰 비중을 차지하는 건물은 모의 분석에 제외되어 있다. 본 연구에서는 연행작용을 고려할 수 있는 Deb2D 모형을 이용하여 하류부에서 토석류의 유동을 건물의 유/무를 구분하여 분석하였다. 우면산 북측사면의 산사태 전 후의 항공 LiDAR DEM을 활용하여 DB를 확보하였고, 추가적으로 수치지형도를 통해 얻은 피해지역 건물들의 형상을 Deb2D 모형에 적용하여 실제 환경과 가까운 모의를 수행하였다. 이러한 자료들을 바탕으로 Deb2D 모형을 이용한 토석류 유동의 분석 및 모의실험을 진행하였고, 발생 지역의 정보가 부족하다는 점을 고려하여 지질특성에 따른 매개변수를 다양한 값으로 산정하여 토석류의 유동을 비교 분석하였다. 건물의 유/무에 따른 토석류 유동의 차이는 유역 하류부인 피해지역에서 모의실험을 통해 나타났다. 이러한 결과를 통하여 연행작용과 건물의 정보를 분석 모형에 추가함으로써 실질적인 인명과 재산 피해를 예측하고, 예방할 수 있을 것으로 기대된다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.29 no.4
• /
• pp.351-357
• /
• 2011

In this study, we have intended to analyze the possibility of using the precise geoid model and to find the best geoid model for working by the airborne LiDAR system. So we have calculated the geoid height from the precise geoid models (KGEOID08, EGM2008, EIGEN-CG03C) and have analyzed results by comparing the geometric geoid height from surveying and geoid heights from geoid models. As a result, the KGEOID08 that had 0.152m of RMSE was assessed the best geoid model for making DEM(DTM) by airborne LiDAR system. Also we have found the needed arrangement and numbers of reference point when the KGEOID08 was used for conversion into orthometric height of LiDAR data.

• Journal of The Geomorphological Association of Korea
• /
• v.18 no.4
• /
• pp.141-152
• /
• 2011

The fluctuation of inundation height due to climate change and sea level rise is expected to cause the socio-economical damage in the coastal zone. To evaluate the inundation damage in Haeundae Beach Area, the inundation height was calculated using the observed data and the range of inundated area and buildings was estimated by applying to DEM data, which was constructed with airborne LiDAR data. The range of inundated area and buildings were estimated with 5 scenario of sea level rise in the condition of minimum and maximum inundation height. When the 181cm, the area of 7.19ha and 5 buildings were expected to be inundated. As 20cm in sea level rises at the minimum of the inundation height, the area of 8.90ha and 8buildings were expected to be inundated. As 30cm, 40cm, 50cm, 60cm in sea level rise, 9.98ha and 9 buildings, 11.11ha and 11buildings, 12.41ha and 11buildings, 14.18ha and 14buildings were expected to be inundated, respectively. When the 526 cm, the area of 32.35ha and 42buildings were expected to be inundated. As 20cm, 30cm, 40cm, 50cm, 60cm in sea level rise at the maximum of the inundation height, 38.94ha and 47buildings, 42.46ha and 52buildings, 45.76ha and 58buildings, 49.51ha and 66buildings, 52.53ha and 72buildings were expected to be inundated, respectively. The leisure and industry facilities, socio-economical installation, habitation are located near by the estimated inundation area, then the inundation damage is expected to be greater scale.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.6 no.3
• /
• pp.33-42
• /
• 2003

As airborne laser scanning technique is developed with high vertical accuracy recently, there come many studies on DEM(digital elevation model creation, building extraction, flood risk mapping and 3D virtual city modeling. This study applied point comparative method, contour comparative method and digital map with scale 1/5,000 to calculate RMSE of DEM in according to resolution that was constructed using rawdata being acquired by airborne laser scanning. As a result, point comparative method showed lower DEM standard error than contour comparative method, it is a reason that contour comparative method was not carried out detailed grid calculation for point comparative method. Also, digital map with scale 1/5,000 showed higher DEM standard error than point comparative method and contour comparative method in below 25.4m that is average horizontal distance among contour line, and showed similar result with contour comparative method in over 25.4m.

• Journal of Korean Society for Geospatial Information Science
• /
• v.16 no.4
• /
• pp.101-107
• /
• 2008

Due to increased interest in environmental friendly ecological development and restoration, civil appeals concerning various environmental and landscape problems are continuously being lodged in cases where open-pit limestone mines are situated in places with eminent natural landscape. In this study, with the open-pit limestone mines located in the Baekdu mountain range as a study area, intends to contribute in recognition of various environmental problems and in the promotion of a reasonable restoration plan through high quality geo-spatial information. And it is planning to establish a method for sustained monitoring of the limestone mining by building intelligent national land information of the study area through combining Airborne Laser Scanning and Terrestrial LiDAR based surveying.