We present system-level responsivity calibration results of the visible and near infrared channels of JPSS-1 VIIRS in the reflective solar band (RSB) from bands M1( 412 nm) to M7 (865 nm). A monochromator-based method based on the Spectral Measurement Assembly (SpMA), and a laser-based calibration method based on Travelling-Spectral Irradiance and Radiance responsivity Calibrations using Uniform Sources (T-SIRCUS) were applied with different illumination methods to obtain the relative and absolute spectral responses (RSR and ASR). The spectral features of RSR for each band are verified by comparing to the component-level spectral transmittance of the VIIRS bandpass filters. Variation of RSR results of a single pixel/detector with respect to the band-averaged for each band is also investigated. Utilization of RSR results from SpMA and T-SIRCUS with different illumination methods as well as the component transmittance results enables us to recognize optical and electrical cross-talk from out-of-band, which is estimated at about 3 %. We also attempted to use the ASRs from T-SIRCUS to validate the gain coefficients derived from an independent radiometric calibration test using a broadband source. Three spectral shapes of flat spectral radiance, Tungsten lamp, and solar emission are used to simulate different scenarios for baseline, pre-launch calibration, and on-orbit calibration to verify the radiometric coefficients with the more accurate NIST-traceable calibration.
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