• Title/Summary/Keyword: digital topography data

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Construction of Farmlands Spatial Information for Reasonable Adjustment of Farmland Use (합리적인 농지이용조정을 위한 농지공간정보구축)

  • Chung, Hoi-Hoon;Na, Sang-Il;Lee, Sang-Hyun;Choi, Jin-Yong
    • Journal of Korean Society of Rural Planning
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    • v.15 no.4
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    • pp.213-220
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    • 2009
  • Farmland spatial data are needed as a basic information in conducting rational use of farmlands in regional scale. This study develops a method that can be used to make up such farmland spatial data in a simple way and to develop a technique to manage them in a unitary way, and examines the effectiveness of the technique by applying it to the case area. A method that Web-Service Raster Image and Digital Cadastal Map can be utilized as a base map was devised. It was designed applying the vector system, in which one lot of farmland is area unit. Raster image and field survey data were combined to increase the accuracy of data. The lot boundaries of the existing boundary map were adjusted to the shapes of actual farmlands using GIS edition function. A proper farmland use classification system to the area characteristics was established and data obtained from the field survey were coded. Usually it is very difficult to identify the size of one lot of actual farmland in the existing space data, based on the results of the case study, the result map showed actual topography very realistically. Also the frequently occurring lot divisions and the serious topographical modifications by natural disasters frequently have made it impossible to survey farmlands on the catastral map in the field. But the final map had a great usefulness in that it may solve such problems by expressing the filed survey results graphically.

Automatic Geometric Calibration of KOMPSAT-2 Stereo Pair Data (KOMPSAT-2 입체영상의 자동 기하 보정)

  • Oh, Kwan-Young;Jung, Hyung-Sup
    • Korean Journal of Remote Sensing
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    • v.28 no.2
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    • pp.191-202
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    • 2012
  • A high resolution satellite imagery such as KOMPSAT-2 includes a material containing rational polynomial coefficient (RPC) for three-dimensional geopositioning. However, image geometries which are calculated from the RPC must have inevitable systematic errors. Thus, it is necessary to correct systematic errors of the RPC using several ground control points (GCPs). In this paper, we propose an efficient method for automatic correction of image geometries using tie points of a stereo pair and the Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) without GCPs. This method includes four steps: 1) tie points extraction, 2) determination of the ground coordinates of the tie points, 3) refinement of the ground coordinates using SRTM DEM, and 4) RPC adjustment model parameter estimation. We validates the performance of the proposed method using KOMPSAT-2 stereo pair. The root mean square errors (RMSE) achieved from check points (CPs) were about 3.55 m, 9.70 m and 3.58 m in X, Y;and Z directions. This means that we can automatically correct the systematic error of RPC using SRTM DEM.

Analysis of Building Object Detection Based on the YOLO Neural Network Using UAV Images (YOLO 신경망 기반의 UAV 영상을 이용한 건물 객체 탐지 분석)

  • Kim, June Seok;Hong, Il Young
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.39 no.6
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    • pp.381-392
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    • 2021
  • In this study, we perform deep learning-based object detection analysis on eight types of buildings defined by the digital map topography standard code, leveraging images taken with UAV (Unmanned Aerial Vehicle). Image labeling was done for 509 images taken by UAVs and the YOLO (You Only Look Once) v5 model was applied to proceed with learning and inference. For experiments and analysis, data were analyzed by applying an open source-based analysis platform and algorithm, and as a result of the analysis, building objects were detected with a prediction probability of 88% to 98%. In addition, the learning method and model construction method necessary for the high accuracy of building object detection in the process of constructing and repetitive learning of training data were analyzed, and a method of applying the learned model to other images was sought. Through this study, a model in which high-efficiency deep neural networks and spatial information data are fused will be proposed, and the fusion of spatial information data and deep learning technology will provide a lot of help in improving the efficiency, analysis and prediction of spatial information data construction in the future.

Change Analysis of Eulsukdo Wetland Using Qualitative Multi-temporal Image Data (다중시기 영상자료를 이용한 을숙도 습지 지역의 정성적 변화분석)

  • Lee, Jae-One;Kim, Yong-Suk;We, Gwang-Jae
    • Journal of the Korean Association of Geographic Information Studies
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    • v.13 no.2
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    • pp.64-73
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    • 2010
  • This research collected some multi-image information of Nakdong River Estuary Eulsukdo area in last 30 years, which are used as the basis information in running the qualitative analysis of the topography relief's deformation. First, to obtain the data, this research carried out a field survey and GCP measurement, then classified and collected the image information by analog and digital image. The acquired images which have passed a high-precise scan process and geometric correction is manufactured by Ortho Mosaic image, then divided them into 9 sections time period classification before we run a qualitative analysis. In late of 1980's there are many changes of environmental topography deformation of the Eulsukdo area which caused by large scale building constructions, appeared to be known through this research. And then in late of 1990's, we organized the wild cultivated lands, started the wetland restoration of the artificial ecology, in 2000's we are able to know the existence of topograph relief change which caused by big scale of bridge construction. Hereafter, in this quick process of the environmental and topographical change of this area caused by the 4 major rivers restoration project, the analysis results of this experiment are expected to be something applicable as important basic data.

A Study on Local Three-Dimensional Visualization Methodology for Effective Analysis of Construction Environments in Extreme Cold Regions (효과적인 극한지 건설환경 분석을 위한 현지 3차원 가시화 방안 연구)

  • Kim, Eui Myoung;Lee, Woo Sik;Hong, Chang Hee
    • Spatial Information Research
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    • v.20 no.6
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    • pp.129-137
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    • 2012
  • For construction project in extreme cold region, it is essential to establish basic data on the site such as topographical data from the early stage of construction of planning and designing, and it is needed to frequently perform site investigation when necessary. However, extreme cold regions are characteristic of being at long distance and difficult in approaching, and special regions such as Antarctica, in particular, are hard to conduct site investigation. Although a site investigation may be conducted, those who can visit Antarctica are sufficiently limited so that most of the staff may participate in construction without knowledge of the site and increase the risk of errors in decision making or designing. In order to resolve such problems, the authors in this study identified methods of building wide-area topographical data and bedrock classification data of exposed areas via remote sensing and of building precise topographical data on the construction site. Also, the authors attempted to present methods by which such data can be managed and visualized integrally via three-dimensional GIS technology and all the participants in construction can learn sense of field and conduct necessary analysis as frequent as possible. The areas around the Jangbogo Antarctic Station were selected to be the research area for conducting effective integrational management and three-dimensional visualization of various spatial data such as wide-area digital elevation model, ortho-images, bedrock classification data, local precise digital elevation model, and site images. The results of this study may enable construction firms to analyze local environments for construction whenever they need for construction in extreme cold regions and then support construction work including decision making or designing.

A Study on the Improvement Methods for Water Supply Facility Management System Implementation by GIS (GIS 기반 상수도 관망관리시스템 구축의 개선 방안에 관한 연구)

  • Yeon, Sang-Ho
    • Journal of the Korean Association of Geographic Information Studies
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    • v.3 no.3
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    • pp.90-97
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    • 2000
  • The study was aimed to extract the improvement measures for the problem on GIS application GIS for water supply and sewerage pipeline facility management in the Jechon city. For this, it performed of analysis of their working and modeling with other relational contents of the water and sewer facility management. As the results, the implementation of water and sewer facility management system by use of GIS has to applying development through relational analysis not only pipeline facility and leaking water protection, pipeline network analysis but also digital topography, drawing data, water user's information.

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Detection of the morphologic change on tidal flat using intertidal DEMs

  • Lee, Yoon-Kyung;Ryu, Joo-Hyung;Eom, Jin-Ah;Kwak, Joon-Young;Won, Joong-Sun
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.247-249
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    • 2006
  • The objective of this study is to detect a inter-tidal topographic change in a decade. Waterline extraction is a one of widely used method to generate digital elevation model (DEM) of tidal flat using multi-temporal optical data. This method has been well known that it is possible to construct detailed topographic relief of tidal flat using waterlines In this study, we generated two sets of tidal flat DEM for the southern Ganghwado. The DEMs showed that the Yeongjongdo northern tidal flat is relatively high elevation with steep gradients. The Ganghwado southern tidal flat is relatively low elevation and gentle gradients. To detect the morphologic change of tidal flat during a decade, we compared between early 1990's DEM and early 2000's DEM. Erosion during a decade is dominant at the west of southern Ganghwado tidal flat, while sedimentation is dominant at the wide channel between the southern Ganghwado and Yeongjongdo tidal flats. This area has been commonly affected by high current and sedimentation energy. Although we are not able to verify the accuracy of the changes in topography and absolute volume of sediments, this result shows that DEM using waterline extraction method is an effective tool for long term topographic change estimation.

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FEASIBILITY OF IMAGE PROCESSING TECHNIQUES FOR LAKE LEVEL EXTRACTION WITH C-BAND SRTM DEM

  • Bhang, Kon-Joon;Schwartz, Franklin Walter;Park, Seok-Soon
    • Proceedings of the KSRS Conference
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    • 2008.10a
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    • pp.173-176
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    • 2008
  • Lake studies play an important role in water management, ecology, and other environmental issues. Typically, monitoring lake levels is the first step on the lake studies. However, for the Prairie Pothole Region (PPR) of North America having millions of small lakes and potholes, on-site measurement for lake levels is almost impossible with the conventional gage stations. Therefore, we employed Geographic Information System (GIS) and remote sensing approach with the Shuttle Radar Topography Mission data to extract lake levels. Several image processing techniques were used to extract lake levels for January, 2000 as a one-time snapshot which will be useful in historic lake level reconstruction. This study is associated with other remote sensing datasets such as Landsat imagery and Digital Orthophoto Quadrangle (DOQ). In this research, firstly, image processing techniques like FFT filtering, Lee-sigma, masking with Canny Edge Detector, and contouring were tested for lake level estimation. The semi-automated contouring technique was developed to accomplish the bulk processing for large amount of lakes in this region. Also, effectiveness of each method for bulk processing was evaluated.

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Estimation of Pollutant Delivery Load in Hydraulic and Hydrologic Aspects for Water Quality Modeling (수질모델링을 위한 유달부하량의 수리·수문학적 산정)

  • Kim, Sang dan;Song, Mee Young;Kim, Hung Soo
    • Journal of Wetlands Research
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    • v.6 no.3
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    • pp.47-54
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    • 2004
  • A hydraulically and hydrologically based estimation method of pollutant delivery load for water quality modeling is proposed. The proposed method works on grid basis and routes overland flows from one cell to the next following the maximum downslope directions. The method is able to consider spatially-varied data of source pollutant, topography, land slopes, soil characteristics, land use and aspects, which can be extracted from geographic information systems (GIS) and from digital elevation models (DEMs). Because of this feature, the proposed method can be expected to be used for evaluating the impacts of various practices on watershed management for water quality.

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Efficient Method to Estimate the Number of Exposed People to Industrial Noise Using the GIS and Three Dimensional Noise Mapping - Focusing on the Industrial Noise - (GIS와 3차원 소음지도를 이용한 소음 노출 인구 산정 방법에 관한 연구 - 공장 소음을 중심으로 -)

  • Ko, Joon-Hee;Chun, Hyung-Joon;Chang, Seo-Il
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.17 no.6 s.123
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    • pp.491-497
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    • 2007
  • Reasonably accurate estimation of the exposed population to the distinct levels of noise is essential to the efficient management of urban environmental noise. This study proposes a method of calculating the number of exposed people to industrial noise by using GIS tool and noise mapping. The exposed population of noise based on estimation of the number of people that lived in each building in urban area is compared with the one based on density of population. This study suggests the five step method that consists of gathering the fundamental data, extracting the property from the digital map, noise mapping based on the three dimensional topography, estimating population that lives in each building, merging the various results with GIS tool, and estimating exposed population to industrial noise through analyzing the noise map with GIS tools.