• Title/Summary/Keyword: Methane retrieval

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Application of Seasonal AERI Reference Spectrum for the Improvement of Cloud data Filtering Method (계절별 AERI 기준 스펙트럼 적용을 통한 구름에 영향을 받은 스펙트럼 자료 제거방법 개선)

  • Cho, Joon-Sik;Goo, Tae-Young;Shin, Jinho
    • Korean Journal of Remote Sensing
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    • v.31 no.5
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    • pp.409-419
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    • 2015
  • The Atmospheric Emitted Radiance Interferometer (AERI) which is the Fourier Transform InfraRed (FTIR) spectrometer has been operated by the National Institute of Meteorological Research (NIMR) in Anmyeon island, South Korea since June 2010. The ground-based AERI with similar hyper-spectral infrared sensor to satellite could be an alternative way to validate satellite-based remote sensing. In this regard, the NIMR has focused on the improvement of Cloud data Filtering Method (CFM) which employed only one reference spectrum of clear sky in winter season. This study suggests Seasonal-Cloud data Filtering Method (S-CFM) which applied seasonal AERI reference spectra. For the comparison of applied S-CFM and CFM, the methane retrievals (surface volume mixing ratio) from AERI spectra are used. The quality of AERI methane retrieval applied S-CFM was significantly more improved than that of CFM. The positive result of S-CFM is similar pattern with the seasonal variation of methane from ground-based in-situ measurement, even if the summer season's methane is retrieved over-estimation. In addition, the comparison of vertical total column of methane from AERI and GOSAT shows good result except for the summer season.

Improvement of Cloud-data Filtering Method Using Spectrum of AERI (AERI 스펙트럼 분석을 통한 구름에 영향을 받은 스펙트럼 자료 제거 방법 개선)

  • Cho, Joon-Sik;Goo, Tae-Young;Shin, Jinho
    • Korean Journal of Remote Sensing
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    • v.31 no.2
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    • pp.137-148
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    • 2015
  • The National Institute of Meteorological Research (NIMR) has operated the Fourier Transform InfraRed (FTIR) spectrometer which is the Atmospheric Emitted Radiance Interferometer (AERI) in Anmyeon island, Korea since June 2010. The ground-based AERI with similar hyper-spectral infrared sensor to satellite could be an alternative way to validate satellite-based remote sensing. In this regard, the NIMR has focused on the improvement of retrieval quality from the AERI, particularly cloud-data filtering method. The AERI spectrum which is measured on a typical clear day is selected reference spectrum and we used region of atmospheric window. We performed test of threshold in order to select valid threshold. We retrieved methane using new method which is used reference spectrum, and the other method which is used KLAPS cloud cover information, each retrieved methane was compared with that of ground-based in-situ measurements. The quality of AERI methane retrievals of new method was significantly more improved than method of used KLAPS. In addition, the comparison of vertical total column of methane from AERI and GOSAT shows good result.