• Title/Summary/Keyword: digital sensing

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Comparison of Visual Interpretation and Image Classification of Satellite Data

  • Lee, In-Soo;Shin, Dong-Hoon;Ahn, Seung-Mahn;Lee, Kyoo-Seock;Jeon, Seong-Woo
    • Korean Journal of Remote Sensing
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    • v.18 no.3
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    • pp.163-169
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    • 2002
  • The land uses of Korean peninsula are very complicated and high-density. Therefore, the image classification using coarse resolution satellite images may not provide good results for the land cover classification. The purpose of this paper is to compare the classification accuracy of visual interpretation with that of digital image classification of satellite remote sensing data such as 20m SPOT and 30m TM. In this study, hybrid classification was used. Classification accuracy was assessed by comparing each classification result with reference data obtained from KOMPSAT-1 EOC imagery, air photos, and field surveys.

Determination of Flood Hydrograph by Remote Sensing Techniques in a Small Watershed (원격탐사 기법에 의한 소유역의 홍수 수문곡선 결정)

  • 남현옥;박경윤;조성익
    • Korean Journal of Remote Sensing
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    • v.5 no.1
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    • pp.13-27
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    • 1989
  • In recent years satellite data have been increasingly used for the analysis of floodprone areas. This study was carried out to demonstrate the usefulness of repetitive satellite imagery in monitoring flood levels of the Pyungchang watershed. Runoff characteristics parameters were analyzed by Soil Conservation Service(SCS) Runoff Curve Number(RCN) based on Landsat imagery and Digital Terrain Model data. The RCN average within the watershed was calculated from RCN estimates for all the pixels(picture elements) and adjusted by antecedent precipitation conditions. The direct runoff hydrograph was derived from the unit hydrograph using SCS dimensionless unit hydrograph and effective rainfalls estimated by the SCS method. In comparsion of the direct runoff hydrograph with the measured rating curve their peak times differ by one hour and peak discharges differ by 5.9 percents of the discharge from each other. It was shown that repetitive satellite image could be very useful in timely estimating watershed runoffs and evaluating ever-changing surface conditions of a river basin.

Development of a multi-sensing technique for temperature and strain field of high-temperature using thermographic phosphors (온도감응형 인광물질을 이용한 온도장 및 열변형 동시 계측 기법 개발)

  • Im, Yujin;Yeom, Eunseop
    • Journal of the Korean Society of Visualization
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    • v.19 no.3
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    • pp.77-83
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    • 2021
  • Solid oxide fuel cell (SOFC) operates at high temperatures in range of 600-800℃. Since layers of SOFC are composed of different substances, different thermal expansion in SOFC can result in defects under high temperature conditions. For understanding relation between temperature field and the thermal deformation in SOFC, temperature and strain field were simultaneously estimated using thermographic phosphors by optical measurement. Temperature fields were obtained by the life-time method, and the temperature differences of one specimen was checked with thermocouple. The thermal deformation was estimated by digital image correlation (DIC) method with extracted phosphorescence images. To investigate the deformation accuracy of DIC measurement, thermographic phosphors were coated with and without grid pattern on aluminum surface. Simultaneous measurement of temperature fields and thermal deformation were carried out for YSZ. This study will be helpful to multi-sensing of temperature field and thermal deformation on SOFC cells.

FEATURE-BASED SPATIAL DATA MODELING FOR SEAMLESS MAP, HISTORY MANAGEMENT AND REAL-TIME UPDATING

  • Kim, Hyeong-Soo;Kim, Sang-Yeob;Seo, Sung-Bo;Kim, Hi-Seok;Ryu, Keun-Ho
    • Proceedings of the KSRS Conference
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    • 2008.10a
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    • pp.433-436
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    • 2008
  • A demand on the spatial data management has been rapidly increased with the introduction and diffusion process of ITS, Telematics, and Wireless Sensor Network, and many different people use the digital map that offers various thematic spatial data. Spatial data for digital map can manage to tile-based and feature-based data. The existing tile-based digital map management systems have difficult problems of data construction, history management, and updating based on a spatial object. In order to solve these problems, this paper proposed the data model for the feature-based digital map management system that is designed for feature-based seamless map, history management, real-time updating of spatial data, and analyzed the validity and utility of the proposed model.

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CREATION OF DIGITAL CITY MODEL FROM A SINGLE KOMPSAT-2 IMAGE

  • Kim, Hye-Jin;Choi, Jae-Wan;Han, You-Kyung;Kim, Yong-II
    • Proceedings of the KSRS Conference
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    • 2008.10a
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    • pp.365-367
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    • 2008
  • A digital city model represents a 3D environment of a city with various city object information such as 3D building model, road, and land cover. Usually, at least two satellite images with some image overlap are necessary and a complex satellite-related computation needs to be carried out to create a city model. This is an expensive technique, because it requires many resources and excessive computational cost. The authors propose a methodology to create a digital city model including 3D building model and land cover information from a single high resolution satellite image. The approach consists of image pan-sharpening, shadow recovery, building occlusion restoration, building model extraction, and land cover classification. We create a digital city model using a single KOMPSAT-2 image and review the result.

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Cast Shadow Extraction of Mountainous Terrain in Satellite Imagery (위성영상에서 산악지역의 그림자 추출)

  • 손홍규;윤공현;송영선
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2004.04a
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    • pp.309-312
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    • 2004
  • In mountainous area with high relief, topography may cause cast shadows due to the blocking of direct solar radiation. Remote sensing images of these landscapes display reduced values of reflectance for shadowed areas compared to non-shadowed areas with similar surface cover characteristics. A variety of approaches are possible, though a common step in various active approaches is first to delineate the shadows using automated algorithm and digital surface model (or digital elevation model). This articles demonstrates a common confusion caused by cast shadows

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Identifying Riparian Water Landscape Change Detection Using Digital Photogrammetry Technique

  • Ahn Seung-mahn;Lee Kyoo-seock
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.25-27
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    • 2004
  • Han River water landscape changes between 1966 and 2002 were detected by interpreting IKONOS images, aerial photographs. Digital photogrammetry technique was used in this process. Most of water landscape change are disappearance of sandbars and meandering streams in 1966. It is mainly due to the stream straightening for housing site development.

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DEM generation of rock slope using laser scanning and digital stereo photogrammetry

  • Jeong Changyub;Park Hyong-Dong
    • 한국지구물리탐사학회:학술대회논문집
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    • 2003.11a
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    • pp.526-528
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    • 2003
  • There are some reports which are about measuring the discontinuity from 3D model of rock surface. To generate 3D model is mainly based on remote sensing technique like laser scanning and digital stereo photogrammetry. It is obtained the DEM of the rock slope using above techniques in this study, and examined a suitability and improvement of the photogrammetry for the rock slope by overlap the DEM. It seems that accuracy of DEM generated by photogrammetry technique is influenced by the geometry of rock and type of joint.

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Optical Scanning Holography - A Review of Recent Progress

  • Poon, Ting-Chung
    • Journal of the Optical Society of Korea
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    • v.13 no.4
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    • pp.406-415
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    • 2009
  • Optical scanning holography (OSH) is a distinct digital holographic technique in that real-time holographic recording a three-dimensional (3-D) object can be acquired by using two-dimensional active optical heterodyne scanning. Applications of the technique so far have included optical scanning cryptography, optical scanning microscopy, 3-D pattern recognition, 3-D holographic TV, and 3-D optical remote sensing. This paper reviews some of the recent progress in OSH. Some possible further works are also discussed.

Automatic Change Detection of Digital Elevation Models Using Matching Method

  • Lee, Seung-Woo;Lee, Ho-Nam;Oh, Hae-Seok
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.393-395
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    • 2003
  • The changes of DEMs(Digital Elevation Models) will be detected to correct the information of DEMs and/or to get the information about themselves. This study suggests the evaluation of DEM using correlation coefficient value between the target and the reference DEMs for detect the changes.

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