• Title/Summary/Keyword: Spectral characteristics

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Near-IR Spectral Features of Haze Particles in the Atmosphere of Titan

  • Kim, Sang Joon
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.1
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    • pp.62.1-62.1
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    • 2013
  • The Cassini/Visual Infrared Mapping Spectrometer (VIMS) observed the sun through the atmosphere of Titan, and provided vertically-resolved 63 spectra from 49 km to 987 km for the 1 - 5 micron range (Bellucci, 2008). Bellucci et al. (2009) analyzed selected spectral ranges where the band absorptions of $CH_4$ and CO are strong by constructing synthetic spectra including $CH_4$ and CO lines, but without including haze absorptions in their synthetic spectra. Kim et al. (2011) and Sim et al. (2013) were able to extract detailed spectral features of fundamental (Dv = 1) and overtone (Dv = 2) bands of the haze from the VIMS spectra by excluding the adjacent influences of strong $CH_4$ absorptions using a radiative transfer program, which includes effects of absorption and emission of lines of these molecules, and absorption and scattering of haze particles. In this presentation, we extend our detailed analyses to other remaining wavelengths in order to provide the spectral characteristics of the Titanian haze for the entire 1 - 5 micron range and to identify any additional haze spectral features and an unidentified feature near 4.3 microns reported by Bellucci et al. (2009).

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MEASUREMENTS OF ALBEDO AND SPECTRAL PATTERNS OF MAN-MADE SATELLITE MATERIALS (인공위성 재질별 반사율 및 분광유형 측정)

  • 이동규;김상준;이준호;한원용;민상웅
    • Journal of Astronomy and Space Sciences
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    • v.19 no.4
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    • pp.319-326
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    • 2002
  • Laboratory tests have been carried out for investigation of the spectroscopic characteristics at visible wavelength of 12 common satellite materials used in satellite bus and payload. The obtained spectral data show that the materials can be classified and identified since their spectral features and albedos distinctly differ among them. It is suggested that the result of the laboratory tests for the satellite materials can be used for the predictions of material types, material composition ratios, sizes, and masses in comparison with the spectral data obtained from observations of new satellites or space debris.

Data Fusion Using Image Segmentation in High Spatial Resolution Satellite Imagery

  • Lee, Jong-Yeol
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.283-285
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    • 2003
  • This paper describes a data fusion method for high spatial resolution satellite imagery. The pixels located around an object edge have spectral mixing because of the geometric primitive of pixel. The larger a size of pixel is, the wider an area of spectral mixing is. The intensity of pixels adjacent edges were modified by the spectral characteristics of the pixels located inside of objects. The methods developed in this study were tested using IKONOS Multispectral and Pan data of a part of Jeju-shi in Korea. The test application shows that the spectral information of the pixels adjacent edges were improved well.

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CORREALTION BETWEEN NON-DESTRUCTIVE QUALITY EVALUATION PARAMETERS AND SPECTRAL REFLECTANCE OF PEACHES

  • Kim, Y.H.;Kim, C.S.;Lee, C.H.
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1993.10a
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    • pp.334-343
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    • 1993
  • In order to evaluate the quality of peaches non-destructively, the surface color and spectral reflectance of KURAKATAWASE, MIBAEKTO and OKUBO cultivar were measured. Also an attempt was made to correlate reflectance characteristics with quality evaluation parameters such as chlorophyll, anthocyanin , soluble solid , and firmness.

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Quality Evaluation Using Spectral Reflectance and Tristimulus Values of Peaches (분광반사특성(分光反射特性)과 삼자극치(三刺戟値)를 이용(利用)한 복숭아의 품질평가(品質評價))

  • Kim, Y.H.
    • Journal of Biosystems Engineering
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    • v.19 no.1
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    • pp.33-41
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    • 1994
  • In order to evaluate the quality of peaches non-destructively, the surface color and spectral reflectances of KURAKATAWASE, MIBAEKTO, and OKUBO cultivar were measured. Also an attempt was made to correlate reflectance characteristics and tristimulus values with quality evaluation parameters such as chlorophyll content, soluble solids, anthocyanin content, and firmness. Further analysis of the correlation coefficients showed that spectral reflectance would be effective for the quality evaluation of peaches.

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A Study on Spectral Envelope Modification using Triangular Filter (삼각필터를 이용한 Spectral 포락변경에 관한 연구)

  • 최성은;김동현;홍광석
    • Proceedings of the IEEK Conference
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    • 2003.07e
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    • pp.2415-2418
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    • 2003
  • In this paper, we present a new filter to adjust formant information. Spectral envelope in speech analysis shows information about characteristics of speech and formant information determines speech timbre. So, if formant position is adjusted, we can verify adjusted speech timbre. A presented filter is to adjust this formant. This filter is composed of triangular filters. Using this filter we could locate the formant frequency at target position.

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Computation of Uniform Hazard Spectrum for Wolsong Nuclear Power Plants. (월성 원전 부지의 등재해도 스펙트럼 계산)

  • 신진수
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1998.10a
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    • pp.297-303
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    • 1998
  • The uniform hazard spectrum of Wolsong Nuclear Power plant Site is computed in order to estimate probabilistically the characteristics of spectral ground response. The spectral hazard values calculated from the seismic zoning maps proposed by eight seismologist are combined with equal weight to produce a uniform hazard spectrum. The uniform hazardd spectra corresponding to reference probabilities of 1.0 $\times$10-4/year and 1.0$\times$10-5/year are presented, which largely depend on the spectral attenuation relation. The computational results of this study contribute to verify the conservatism of the design ground spectrum of Wolsong Nuclear Power Plant.

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A Study on Natural Convection from Two Cylinders in a Cavity

  • Mochimaru Yoshihiro;Bae Myung-Whan
    • Journal of Mechanical Science and Technology
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    • v.20 no.10
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    • pp.1773-1778
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    • 2006
  • Steady-state natural convection heat transfer characteristics from cylinders in a multiply-connected bounded region are clarified. A spectral finite difference scheme (spectral decomposition of the system of partial differential equations, semi-implicit time integration) is applied in numerical analysis, with a boundary-fitted conformal coordinate system through a Jacobian elliptic function with a successive transformation to formulate a system of governing equations in terms of a stream function, vorticity and temperature. Multiplicity of the domain is expressed explicitly.

Vicarious Calibration-based Robust Spectrum Measurement for Spectral Libraries Using a Hyperspectral Imaging System

  • Chi, Junhwa
    • Korean Journal of Remote Sensing
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    • v.34 no.4
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    • pp.649-659
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    • 2018
  • The aim of this study is to develop a protocol for obtaining spectral signals that are robust to varying lighting conditions, which are often found in the Polar regions, for creating a spectral library specific to those regions. Because hyperspectral image (HSI)-derived spectra are collected on the same scale as images, they can be directly associated with image data. However, it is challenging to find precise and robust spectra that can be used for a spectral library from images taken under different lighting conditions. Hence, this study proposes a new radiometric calibration protocol that incorporates radiometric targets with a traditional vicarious calibration approach to solve issues in image-based spectrum measurements. HSIs obtained by the proposed method under different illumination levels are visually uniform and do not include any artifacts such as stripes or random noise. The extracted spectra capture spectral characteristics such as reflectance curve shapes and absorption features better than those that have not been calibrated. The results are also validated quantitatively. The calibrated spectra are shown to be very robust to varying lighting conditions and hence are suitable for a spectral library specific to the Polar regions.