18 September 1997 SWIR nonlinear radiometric response due to errors in relative spectral response
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Pre-launch instrument calibration testing of the current series of GOES Imagers and Sounders has shown a systematic non-linearity in the radiometric response of the SWIR channels of approximately 0.2 percent. Possible mechanisms for the observed non-linearity include; inherent InSb detector non-linearity, non-constant temperature error on the blackbody calibration target, relative spectral response error, and electronics non-linearity. A calibration model common to the GOES and POES radiometers is presented. The sensitivity of the SWIR channels' non-linear response to errors in spectral response is derived. Systematic shift of spectral response center wavenumber of approximately 10 cm-1 are found to induce a 0.1 percent non-linearity in response. Pre-launch calibration coefficients from recent NOAA radiometers are analyzed. Operational calibration errors caused by incorrect quadratic coefficients are found to be as large as 0.15K for warm scenes.
© (1997) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Edward C. Wack, Edward C. Wack, } "SWIR nonlinear radiometric response due to errors in relative spectral response", Proc. SPIE 3117, Earth Observing Systems II, (18 September 1997); doi: 10.1117/12.278923; https://doi.org/10.1117/12.278923

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