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assessment of modis rsb detector uniformity using deep convective cloudsFor satellite sensor, the striping observed in images is typically associated with the relative multiple detector gain difference derived from the calibration. A method using deep convective cloud (DCC) measurements to assess the difference among detectors after calibration is proposed and demonstrated for select reflective solar bands (RSBs) of the Moderate Resolution Imaging Spectroradiometer (MODIS). Each detector of MODIS RSB is calibrated independently using a solar diffuser (SD). Although the SD is expected to accurately characterize detector response, the uncertainties associated with the SD degradation and characterization result in inadequacies in the estimation of each detector's gain. This work takes advantage of the DCC technique to assess detector uniformity and scan mirror side difference for RSB. The detector differences for Terra MODIS Collection 6 are less than 1% for bands 1, 3-5, and 18 and up to 2% for bands 6, 19, and 26. The largest difference is up to 4% for band 7. Most Aqua bands have detector differences less than 0.5% except bands 19 and 26 with up to 1.5%. Normally, large differences occur for edge detectors. The long-term trending shows seasonal oscillations in detector differences for some bands, which are correlated with the instrument temperature. The detector uniformities were evaluated for both unaggregated and aggregated detectors for MODIS band 1 and bands 3-7, and their consistencies are verified. The assessment results were validated by applying a direct correction to reflectance images. These assessments can lead to improvements to the calibration algorithm and therefore a reduction in striping observed in the calibrated imagery.
Document ID
20160007849
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Chang, Tiejun
(Science Systems and Applications, Inc. Greenbelt, MD, United States)
Xiong, Xiaoxiong (Jack)
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Angal, Amit
(Science Systems and Applications, Inc. Greenbelt, MD, United States)
Mu, Qiaozhen
(Science Systems and Applications, Inc. Greenbelt, MD, United States)
Date Acquired
June 23, 2016
Publication Date
May 5, 2016
Publication Information
Publication: Journal of Geophysical Research: Atmospheres
Volume: 121
Issue: 9
ISSN: 2169-897X
Subject Category
Earth Resources and Remote Sensing
Meteorology and Climatology
Report/Patent Number
GSFC-E-DAA-TN33038
Funding Number(s)
CONTRACT_GRANT: NNG15HQ01C
Distribution Limits
Public
Copyright
Other
Keywords
Clouds
RSB detector
MODIS