• Title/Summary/Keyword: Emissivity Calibration

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THERMAL MODELS AND FAR INFRARED EMISSION OF ASTEROIDS

  • KIM SAM;LEE HYUNG MOK;NAKAGAWA TAKAO;HASEGAWA SUNAO
    • Journal of The Korean Astronomical Society
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    • v.36 no.1
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    • pp.21-31
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    • 2003
  • ASTRO-F /FIS will carry out all sky survey in the wavelength from 50 to 200 ${\mu}m$. At far infrared, stars and galaxies may not be good calibration sources because the IR fluxes could be sensitive to the dust shell of stars and star formation activities of galaxies. On the other hand, asteroids could be good calibration sources at far infrared because of rather simple spectral energy distribution. Recent progresses in thermal models for asteroids enable us to calculate the far infrared flux fairly accurately. We have derived the Bond albedos and diameters for 559 asteroids based on the IRAS and ground based optical data. Using these thermal parameters and standard thermal model, we have calculated the spectral energy distributions of asteroids from 10 to 200 ${\mu}m$. We have found that more than $70\%$ of our sample asteroids have flux errors less than $10\%$ within the context of the best fitting thermal models. In order to assess flux uncertainties due to model parameters, we have computed SEDs by varing external parameters such as emissivity, beaming parameter and phase integral. We have found that about 100 asteroids can be modeled to be better than $5.8\%$ of flux uncertainties. The systematic effects due to uncertainties in phase integral are not so important.

Method for Measuring Mechanical Behaviors of Thin Films at High Temperature (고온에서 박막의 기계적 거동 측정 방법)

  • Lim, Sang-Chai;Joo, Jae-Hwang;Kang, Ki-Ju
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.1
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    • pp.102-108
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    • 2003
  • Recently, the authors have developed a new material test system fur thin film at the high temperature. It is so compact and precise with sub micron resolution that it seems to be a useful tool fur research of the oxide film growth, its mechanical behavior and failure mechanism. To this end. in this paper three methologies are described for in-situ monitoring of the displacement & strain and the temperature, the oxide thickness. These are the Laser Speckle analysis with digital image correlation technique, the two-color infra-red thermometer and the laser reflection interferometry respectively. The calibration results and some issues which should be addressed for practical application are presented.

Establishment of Thermal Infrared Observation System on Ieodo Ocean Research Station for Time-series Sea Surface Temperature Extraction (시계열 해수면온도 산출을 위한 이어도 종합해양과학기지 열적외선 관측 시스템 구축)

  • KANG, KI-MOOK;KIM, DUK-JIN;HWANG, JI-HWAN;CHOI, CHANGHYUN;NAM, SUNGHYUN;KIM, SEONGJUNG;CHO, YANG-KI;BYUN, DO-SEONG;LEE, JOOYOUNG
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.22 no.3
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    • pp.57-68
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    • 2017
  • Continuous monitoring of spatial and temporal changes in key marine environmental parameters such as SST (sea surface temperature) near IORS (Ieodo Ocean Research Station) is demanded to investigate the ocean ecosystem, climate change, and sea-air interaction processes. In this study, we aimed to develop the system for continuously measuring SST using a TIR (thermal infrared) sensor mounted at the IORS. New SST algorithm is developed to provide SST of better quality that includes automatic atmospheric correction and emissivity calculation for different oceanic conditions. Then, the TIR-based SST products were validated against in-situ water temperature measurements during May 17-26, 2015 and July 15-18, 2015 at the IORS, yielding the accuracy of 0.72-0.85 R-square, and $0.37-0.90^{\circ}C$ RMSE. This TIR-based SST observing system can be installed easily at similar Ocean Research Stations such as Sinan Gageocho and Ongjin Socheongcho, which provide a vision to be utilized as calibration site for SST remotely sensed from satellites to be launched in future.