• Title/Summary/Keyword: Imagery

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Detection of Small Shallow-water Coral Reefs on Landsat Imagery

  • Trisirisatayawong, Itthi;Samanloh, Watcharee
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.479-481
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    • 2003
  • Large number of coral reefs in Thailand waters make the use of satellite imagery probably the only practical method for their monitoring. This paper reports the result of detecting small shallow-water coral reef by using maximum likelihood classification technique. Combination of blue/green and near-infrared band ratio are used as spectral signatures derived from a Landsat 7 imagery covering western portion of the Gulf of Thailand. Result assessment reveals accuracy significantly over 60 percent. The result is encouraging and would be a basis for further study to realize the full potential and limitation of this technique.

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Visualization Of Aerial Color Imagery Through Shadow Effect Correction

  • Sohn, Hong-Gyoo;Yun, Kong-Hyun;Yang, In-Tae;Lee, Kangwon
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2004.02a
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    • pp.64-72
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    • 2004
  • Correction of shadow effects is critical step for image interpretation and feature extraction from aerial imagery. In this paper, an efficient algorithm to correct shadow effects from aerial color imagery is presented. The following steps have been performed to remove the shadow effect. First, the shadow regions are precisely located using the solar position and the height of ground objects derived from LIDAR (Light Detection and Ranging) data. Subsequently, segmentation of context regions is implemented for accurate correction with existing digital map. Next step, to calculate correction factor the comparison between the context region and the same non-shadowed context region is made. Finally, corrected image is generated by correcting the shadow effect. The result presented here helps to accurately extract and interpret geo-spatial information from aerial color imagery

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A Study on Estimation of Water Depth Using Hyperspectral Satellite Imagery (초분광 위성영상을 이용한 수심산정에 관한 연구)

  • Yu, Yeong-Hwa;Kim, Youn-Soo;Lee, Sun-Gu
    • Aerospace Engineering and Technology
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    • v.7 no.1
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    • pp.216-222
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    • 2008
  • Purpose of this research is estimation of water depth by hyperspectral remote sensing in area that access of ship is difficult. This research used EO-l Hyperion satellite imagery. Atmospheric and geometric correction is executed. Compress of band used MNF transforms. Diffuse Attenuation Coefficient of target area is decided in imagery for water depth estimation. Determination of Emdmember in pixel is using Linear Spectral Unmixing techniques. Water depth estimated using this result.

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Applications of Landsat Imagery and Digital Terrain Model Data to River Basin Analyses (Landsat 영상과 DTM 자료의 하천유역 해석에의 응용기법 개발)

  • 조성익;박경윤;최규홍;최원식
    • Korean Journal of Remote Sensing
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    • v.2 no.2
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    • pp.117-131
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    • 1986
  • The purpose of this study was to develop techniques acquiring hydrologic parameters that affect runoff conditions from Landsat imagery. Runoff conditions in a study area were analyzed by employing the U.S. Soil Conservation Service(SCS) Method. SCS runoff curve numbers(CN) were estimated by the computer analysis of Landsat imagery and digiral terrain model(DTM) data. The SCS Method requires land use/cover and soil conditions of the area as input parameters. A land use/cover map of 5 hydrological classes was produced from the Landsat multi-spectral scannerr imagery. Slope-gradient and contour and contour maps were also made using the DTM topographic data. Inundation areas depending on reservoir levels were able to be mapped on the Landsat scene by combining the contour data.

Use of Crown Feature Analysis to Separate the Two Pine Species in QuickBird Imagery

  • Kim, Cheon
    • Korean Journal of Remote Sensing
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    • v.24 no.3
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    • pp.267-272
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    • 2008
  • Tree species-specific estimates with spacebome high-resolution imagery improve estimation of forest biomass which is needed to predict the long term planning for the sustainable forest management(SFM). This paper is a contribution to develop crown distinguishing coniferous species, Pinus densiflora and Pinus koraiensis, from QuickBird imagery. The proposed feature analysis derived from shape parameters and first and second-order statistical texture features of the same test area were compared for the two species separation and delineation. As expected, initial studies have shown that both formfactor and compactness shape parameters provided the successful differentiating method between the pine species within the compartment for single crown identification from spaceborne high resolution imagery. Another result revealed that the selected texture parameters - the mean, variance, angular second moment(ASM) - in the infrared band image could produce good subset combination of texture features for representing detailed tree crown outline.

Occlusion Restoration of Synthetic Stereomate for Remote Sensing Imagery

  • Kim, Hye-Jin;Choi, Jae-Wan;Chang, Ho-Wook;Ryu, Ki-Yun
    • Korean Journal of Remote Sensing
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    • v.23 no.5
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    • pp.439-445
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    • 2007
  • Stereoscopic viewing is an efficient technique for not only computer vision but also remote sensing applications. Generally, stereo pair obtained at the same time is necessary for 3D viewing, but it is possible to synthesize a stereomate suitable for stereo view with a single image and disparity-map. There have been researches concerning the generation of the synthetic stereomate from remote sensing imagery. However it is hard to find researches concerning the restoration of occlusion in stereomate. In this paper, we generated synthetic stereomates from remote sensing images, focused on the occlusion restoration. In order to figure out proper restoration methods depending on the spatial resolution of remote sensing imagery, we tested several methods including general interpolation and inpainting technique, then evaluated the results.

Application of the 3D Discrete Wavelet Transformation Scheme to Remotely Sensed Image Classification

  • Yoo, Hee-Young;Lee, Ki-Won;Kwon, Byung-Doo
    • Korean Journal of Remote Sensing
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    • v.23 no.5
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    • pp.355-363
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    • 2007
  • The 3D DWT(The Three Dimensional Discrete Wavelet Transform) scheme is potentially regarded as useful one on analyzing both spatial and spectral information. Nevertheless, few researchers have attempted to process or classified remotely sensed images using the 3D DWT. This study aims to apply the 3D DWT to the land cover classification of optical and SAR(Synthetic Aperture Radar) images. Then, their results are evaluated quantitatively and compared with the results of traditional classification technique. As the experimental results, the 3D DWT shows superior classification results to conventional techniques, especially dealing with the high-resolution imagery and SAR imagery. It is thought that the 3D DWT scheme can be extended to multi-temporal or multi-sensor image classification.

A Simplified Strategy for the Epipolar Geometry of Linear Pushbroom Imagery (선형 Pushbroom 영상의 에피폴라 기하모델 수립을 위한 간소화된 방법론)

  • 이해연;박원규
    • Korean Journal of Remote Sensing
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    • v.18 no.2
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    • pp.97-105
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    • 2002
  • In this paper, we proposed a simplified strategy for the epipolarity of linear pushbroom imagery. The proposed strategy is verified on "Gupta and Hartly" sensor model and "Orun and Natarajan" sensor model. It is also compared with the precise epipolarity model of each sensor model on SPOT and KOMPSAT imagery. For the quantitative analysis, 20 ground control points are used as independent checking points. Based on the results, the accuracy of the proposed strategy is not different from that of the precise epipolarity model of each sensor model (below 0.1 pixels). Under the worst circumstance, the proposed strategy is robust. We can assure that the proposed strategy will show high accuracy on most of sensor models based on the co-linearity equations.