Spectral Calibration Algorithm for the Geostationary Environment Monitoring Spectrometer (GEMS)
- 주제(키워드) GEMS , spectral calibration , hyperspectral instrument
- 주제(기타) Remote Sensing
- 설명문(일반) [Kang, Mina] Ewha Womans Univ, Dept Atmospher Sci & Engn, 52 Ewhayeodae Gil, Seoul 03760, South Korea; [Ahn, Myoung-Hwan] Ewha Womans Univ, Dept Climate & Energy Syst Engn, 52 Ewhayeodae Gil, Seoul 03760, South Korea; [Liu, Xiong] Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA; [Jeong, Ukkyo] Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, 5825 Univ Res Ctr, College Pk, MD 20740 USA; [Jeong, Ukkyo] NASA, Goddard Space Flight Ctr, 8800 Greenbelt Rd, Greenbelt, MD 20771 USA; [Kim, Jhoon] Yonsei Univ, Dept Atmospher Sci, 50 Yonsei Ro, Seoul 03722, South Korea
- 관리정보기술 faculty
- 등재 SCIE, SCOPUS
- OA유형 Green Published, gold, Green Submitted
- 발행기관 MDPI
- 발행년도 2020
- URI http://www.dcollection.net/handler/ewha/000000174609
- 본문언어 영어
- Published As http://dx.doi.org/10.3390/rs12172846
초록/요약
The Geostationary Environment Monitoring Spectrometer (GEMS) onboard the Geostationary Korean Multi-Purpose Satellite 2B was successfully launched in February 2020. GEMS is a hyperspectral spectrometer measuring solar irradiance and Earth radiance in the wavelength range of 300 to 500 nm. This paper introduces the spectral calibration algorithm for GEMS, which uses a nonlinear least-squares approach. Sensitivity tests for a series of unknown algorithm parameters such as spectral range for fitting, spectral response function (SRF), and reference spectrum were conducted using the synthetic GEMS spectrum prepared with the ground-measured GEMS SRF. The test results show that the required accuracy of 0.002 nm is achievable provided the SRF and the high-resolution reference spectrum are properly prepared. Such a satisfactory performance is possible mainly due to the inclusion of additional fitting parameters of spectral scales (shift, squeeze, and high order shifts) and SRF (width, shape and asymmetry). For the application to the actual GEMS data, in-orbit SRF is to be monitored using an analytic SRF function and the measured GEMS solar irradiance, while a reference spectrum is going to be selected during the instrument in-orbit test. The calibrated GEMS data is expected to be released by the end of 2020.
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