• Title/Summary/Keyword: Large scale mapping

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Visual Mapping from Spatiotemporal Table Information to 3-Dimensional Map (시-공간 도표정보의 3차원 지도 기반 가시화기법)

  • Lee, Seok-Jun;Jung, Soon-Ki
    • Journal of the HCI Society of Korea
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    • v.1 no.2
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    • pp.51-58
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    • 2006
  • Information visualization, generally speaking, consists of three steps: transform from raw data to data model, visual mapping from data model to visual structure, and transform from visual structure to information model. In this paper, we propose a visual mapping method from spatiotemporal table information, which is related to events in large-scale building, to 3D map metaphor. The process has also three steps as follows. First, after analyzing the table attributes, we carefully define a context to fully represent the table-information. Second, we choose meaningful attribute sets from the context. Third, each meaningful attribute set is mapped to one well defined visual structure. Our method has several advantages. First, users can intuitively achieve non-spatial information through the 3D map which is a powerful spatial metaphor. Second, this system shows various visual mapping method applicable to other data models in the form of table, especially GIS. After describing the whole concept of our visual mapping, we will show the results of implementation for several requests.

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A new Observation Model to Improve the Consistency of EKF-SLAM Algorithm in Large-scale Environments (광범위 환경에서 EKF-SLAM의 일관성 향상을 위한 새로운 관찰모델)

  • Nam, Chang-Joo;Kang, Jae-Hyeon;Doh, Nak-Ju Lett
    • The Journal of Korea Robotics Society
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    • v.7 no.1
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    • pp.29-34
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    • 2012
  • This paper suggests a new observation model for Extended Kalman Filter based Simultaneous Localization and Mapping (EKF-SLAM). Since the EKF framework linearizes non-linear functions around the current estimate, the conventional line model has large linearization errors when a mobile robot locates faraway from its initial position. On the other hand, the model that we propose yields less linearization error with respect to the landmark position and thus suitable in a large-scale environment. To achieve it, we build up a three-dimensional space by adding a virtual axis to the robot's two-dimensional coordinate system and extract a plane by using a detected line on the two-dimensional space and the virtual axis. Since Jacobian matrix with respect to the landmark position has small value, we can estimate the position of landmarks better than the conventional line model. The simulation results verify that the new model yields less linearization errors than the conventional line model.

Surface Water Mapping of Remote Sensing Data Using Pre-Trained Fully Convolutional Network

  • Song, Ah Ram;Jung, Min Young;Kim, Yong Il
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.36 no.5
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    • pp.423-432
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    • 2018
  • Surface water mapping has been widely used in various remote sensing applications. Water indices have been commonly used to distinguish water bodies from land; however, determining the optimal threshold and discriminating water bodies from similar objects such as shadows and snow is difficult. Deep learning algorithms have greatly advanced image segmentation and classification. In particular, FCN (Fully Convolutional Network) is state-of-the-art in per-pixel image segmentation and are used in most benchmarks such as PASCAL VOC2012 and Microsoft COCO (Common Objects in Context). However, these data sets are designed for daily scenarios and a few studies have conducted on applications of FCN using large scale remotely sensed data set. This paper aims to fine-tune the pre-trained FCN network using the CRMS (Coastwide Reference Monitoring System) data set for surface water mapping. The CRMS provides color infrared aerial photos and ground truth maps for the monitoring and restoration of wetlands in Louisiana, USA. To effectively learn the characteristics of surface water, we used pre-trained the DeepWaterMap network, which classifies water, land, snow, ice, clouds, and shadows using Landsat satellite images. Furthermore, the DeepWaterMap network was fine-tuned for the CRMS data set using two classes: water and land. The fine-tuned network finally classifies surface water without any additional learning process. The experimental results show that the proposed method enables high-quality surface mapping from CRMS data set and show the suitability of pre-trained FCN networks using remote sensing data for surface water mapping.

Nano-Resolution Connectomics Using Large-Volume Electron Microscopy

  • Kim, Gyu Hyun;Gim, Ja Won;Lee, Kea Joo
    • Applied Microscopy
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    • v.46 no.4
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    • pp.171-175
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    • 2016
  • A distinctive neuronal network in the brain is believed to make us unique individuals. Electron microscopy is a valuable tool for examining ultrastructural characteristics of neurons, synapses, and subcellular organelles. A recent technological breakthrough in volume electron microscopy allows large-scale circuit reconstruction of the nervous system with unprecedented detail. Serial-section electron microscopy-previously the domain of specialists-became automated with the advent of innovative systems such as the focused ion beam and serial block-face scanning electron microscopes and the automated tape-collecting ultramicrotome. Further advances in microscopic design and instrumentation are also available, which allow the reconstruction of unprecedentedly large volumes of brain tissue at high speed. The recent introduction of correlative light and electron microscopy will help to identify specific neural circuits associated with behavioral characteristics and revolutionize our understanding of how the brain works.

Automatic Extraction of Land Cover information By Using KOMPSAT-2 Imagery (KOMPSAT-2 영상을 이용한 토지피복정보 자동 추출)

  • Lee, Hyun-Jik;Ru, Ji-Ho;Yu, Young-Geol
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2010.04a
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    • pp.277-280
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    • 2010
  • There is a need to convert the old low- or medium-resolution satellite image-based thematic mapping to the high-resolution satellite image-based mapping of GSD 1m grade or lower. There is also a need to generate middle- or large-scale thematic maps of 1:5,000 or lower. In this study, the DEM and orthoimage is generated with the KOMPSAT-2 stereo image of Yuseong-gu, Daejeon Metropolitan City. By utilizing the orthoimage, automatic extraction experiments of land cover information are generated for buildings, roads and urban areas, raw land(agricultural land), mountains and forests, hydrosphere, grassland, and shadow. The experiment results show that it is possible to classify, in detail, for natural features such as the hydrosphere, mountains and forests, grassland, shadow, and raw land. While artificial features such as roads, buildings, and urban areas can be easily classified with automatic extraction, there are difficulties on detailed classifications along the boundaries. Further research should be performed on the automation methods using the conventional thematic maps and all sorts of geo-spatial information and mapping techniques in order to classify thematic information in detail.

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A Study on the Mapping of Risk Factor with Performance Index in Urban Regeneration Project (도시재생사업 성과지표와 위험요인 연계 방안 연구)

  • Yu, Young-Jeong;Kim, Seon-Gyoo
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2008.11a
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    • pp.497-500
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    • 2008
  • Recently, the urban regeneration project has been performed actively at home and abroad. The stake-holders in urban regeneration project are various and complicated, and has large scale during a long life period. Also they show the characteristics of a mega-project and most mixed-use form. Therefore, the urban regeneration has a lot of potential risk factors from project beginning to completion. It means they need efficient and continuous risk management in terms of performance measurement. But the current domestic construction project does not reflect risk management in view of performance measurement. This study proposes the risk management methodology by mapping risk factors with major performance indexes of the urban regeneration project.

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Application of QuickBird Imagery for the Production of Digital Map (수치지도 제작을 위한 QuickBird 영상의 활용)

  • Kang, Joon-Mook;Yoon, Hee-Cheon;Kim, Youn-Gwan;Park, Joon-Kyu
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.26 no.1
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    • pp.63-71
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    • 2008
  • Recently according to supplying high resolution satellite imagery, we take much interest in the update and the revision of digital map and thematic map based on the satellite images. This study analyzed the modeling accuracy for QuickBird imagery and produced the digital map on a scale 1 to 5000 by way of showing an example. find an exhibition digital map was analyzed the positioning accuracy for the presentation of the possibility and the utility in the production and the revision to the digital map using QuickBird imagery. In order to analyze accuracies of constructed data, the digital topographic maps of 1:5000 scale which were produced by Korea National Geographic information Institute(NGI) were used. As a result, the RMSE was calculated at ${\pm}2.207$ m and 2.39 m in x and y direction respectively and it is within the permissible accuracy required for mapping on a scale of 1 to 5000 on the mapping rule notified by the National Geographic Information Institute. It is expected that the results of this study will be fully used in the field of large scale digital mapping and be utilized as basic information in applied field of the production and the revision of digital map.

Developing a Work Procedure for Efficient Map Generalization (효율적인 일반화 자료처리를 위한 작업공정 개발)

  • Choi, Seok-Keun;Kim, Myung-Ho;Hwang, Chang-Sup
    • Journal of the Korean Association of Geographic Information Studies
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    • v.6 no.3
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    • pp.73-82
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    • 2003
  • This paper proposes a work procedure for generalizing large-scale digital maps ver. 2.0(1/5,000) into a small-scale digital map(1/25,000). Unlike a existent digital map, the digital map ver. 2.0 has a variety of attribute data as well as graphic data. To perform an efficient map generalization with these structural properties, we establish a work procedure as follow; firstly, delete layers which don't exist in small-scale digital map's feature code, and secondly, generalize features which have been classified into 8 layers, and finally merge 8 layers which have been generalized into 1 layer. Therefore, we expect that a work procedure which is proposed in this paper will play a fundamental role in automated generalization system and will contribute to small-scale digital mapping and thematic mapping.

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Methodology to Apply Low Spatial Resolution Optical Satellite Images for Large-scale Flood Mapping (대규모 홍수 매핑을 위한 저해상도 광학위성영상의 활용 방법)

  • Piao, Yanyan;Lee, Hwa-Seon;Kim, Kyung-Tak;Lee, Kyu-Sung
    • Korean Journal of Remote Sensing
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    • v.34 no.5
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    • pp.787-799
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    • 2018
  • Accurate and effective mapping is critical step to monitor the spatial distribution and change of flood inundated area in large scale flood event. In this study, we try to suggest methods to use low spatial resolution satellite optical imagery for flood mapping, which has high temporal resolution to cover wide geographical area several times per a day. We selected the Sebou watershed flood in Morocco that was occurred in early 2010, in which several hundred $km^2$ area of the Gharb lowland plain was inundated. MODIS daily surface reflectance product was used to detect the flooded area. The study area showed several distinct spectral patterns within the flooded area, which included pure turbid water and turbid water with vegetation. The flooded area was extracted by thresholding on selected band reflectance and water-related spectral indices. Accuracy of these flooding detection methods were assessed by the reference map obtained from Landsat-5 TM image and qualitative interpretation of the flood map derived. Over 90% of accuracies were obtained for three methods except for the NDWI threshold. Two spectral bands of SWIR and red were essential to detect the flooded area and the simple thresholding on these bands was effective to detect the flooded area. NIR band did not play important role to detect the flooded area while it was useful to separate the water-vegetation mixed flooded classes from the purely water surface.

Accuracy Analysis of Ortho Imagery with Different Topographic Characteristic (지역적 특성에 따른 정사영상의 정확도 분석)

  • Jo, Hyun-Wook;Park, Joon-Kyu
    • Journal of the Korean Association of Geographic Information Studies
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    • v.11 no.1
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    • pp.80-89
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    • 2008
  • Mapping applications using satellite imagery have been possible to quantitative analysis since SPOT satellite with stereo image was launched. Especially, high resolution satellite imagery was efficiently used in the field of digital mapping for the areas which are difficult to produce large-scale maps by aerial photogrammetry or carry out ground control point surveying due to unaccessibility. This study extracted the geospatial information out of consideration for topographic characteristic from ortho imagery of the National Geospatial-intelligence Agency(NGA) in the United States of America and analyzed the accuracy of plane coordinate for ortho imagery. For this purpose, the accuracy according to topographic character by comparison between both extraction data from ortho imagery and the digital topographic maps of 1:5000 scale which were produced by Korea National Geographic Information Institute(NGI) was evaluated. It is expected that the results of this study will be fully used as basic information for ground control point acquisition or digital mapping in unaccessible area.

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