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Products of the SNPP VIIRS SD Screen Transmittance and the SD BRDFs From Both Yaw Maneuver and Regular On-Orbit DataTo ensure data quality, the Earth-observing Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi National Polar-orbiting Partnership satellite regularly performs on-orbit radiometric calibration of its 22 spectral bands. The primary radiance source for the calibration of the VIIRS reflective solar bands (RSBs) is a sunlit onboard solar diffuser (SD).During the calibration process, sunlight goes through a perforated plate (the SD screen) and then strikes the SD. The sunlight, scattered off the SD of near-Lambertian property, is used for the calibration. Consequently, the spectral radiance of the scattered sunlight is proportional to the product of the SD screen transmittance and the SD bidirectional reflectance distribution function (BRDF) value at the observation direction. The BRDF value is decomposed to the product of its initial value at launch and a numerical degradation factor that quantifies the decrease from the initial value. The degradation factor is determined by an onboard SD stability monitor (SDSM). During the BRDF degradation factor determination process, the SDSM receives the SD scattered sunlight and the sunlight that goes through another perforated plate at almost the same time. The ratio of the signal strengths from the two observations is used to determine the BRDF degradation factor. Consequently, the RSB radiometric calibration requires the accurate knowledge of the product of the SD screen transmittance and the initial BRDF value as sensed by the RSB and the SDSM detectors. We use both yaw maneuver and a small portion of regular on-orbit data to determine the products.
Document ID
Acquisition Source
Goddard Space Flight Center
Document Type
Reprint (Version printed in journal)
Lei, Ning
(Science Systems and Applications, Inc. Lanham, MD, United States)
Xiong, Xiaoxiong
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Date Acquired
June 14, 2017
Publication Date
January 16, 2017
Publication Information
Publication: IEEE Transactions on Geoscience and Remote Sensing
Publisher: IEEE
Volume: 55
Issue: 4
ISSN: 0196-2892
e-ISSN: 1558-0644
Subject Category
Earth Resources And Remote Sensing
Report/Patent Number
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