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brdf characterization and calibration inter-comparison between terra modis, aqua modis, and s-npp viirsThe inter-comparison of reflective solar bands (RSB) between Terra MODIS, Aqua MODIS, and SNPP VIIRS is very important for assessment of each instrument's calibration and to identify calibration improvements. One of the limitations of using their ground observations for the assessment is a lack of the simultaneous nadir overpasses (SNOs) over selected pseudo-invariant targets. In addition, their measurements over a selected Earth view target have significant difference in solar and view angles, and these differences magnify the effects of Bidirectional Reflectance Distribution Function (BRDF). In this work, an inter-comparison technique using a semi-empirical BRDF model is developed for reflectance correction. BRDF characterization requires a broad coverage of solar and view angles in the measurements over selected pseudo-invariant targets. Reflectance measurements over Libya 1, 2, and 4 desert sites from both the Aqua and Terra MODIS are regressed to a BRDF model with an adjustable coefficient accounting for the calibration difference between the two instruments. The BRDF coefficients for three desert sites for MODIS bands 1 to 9 are derived and the wavelength dependencies are presented. The analysis and inter-comparison are for MODIS bands 1 to 9 and VIIRS moderate resolution radiometric bands (M bands) M1, M2, M4, M5, M7, M8, M10 and imaging bands (I bands) I1-I3. Results show that the ratios from different sites are in good agreement. The ratios between Terra and Aqua MODIS from year 2003 to 2014 are presented. The inter-comparison between MODIS and VIIRS are analyzed for year 2014.
Document ID
20170004638
Document Type
Conference Paper
External Source(s)
Authors
Chang, Tiejun
(Science Systems and Applications, Inc. Lanham, MD, United States)
Xiong, Xiaoxiong (Jack)
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Angal, Amit
(Science Systems and Applications, Inc. Lanham, MD, United States)
Wu, Aisheng
(Science Systems and Applications, Inc. Lanham, MD, United States)
Date Acquired
May 18, 2017
Publication Date
October 19, 2016
Publication Information
Publication: SPIE Proceedings: Sensors, Systems, and Next-Generation Satellites XX
Volume: 1000
Subject Category
Earth Resources and Remote Sensing
Report/Patent Number
GSFC-E-DAA-TN42689
Meeting Information
Sensors, Systems, and Next-Generation Satellites XX(Edinburgh)
Funding Number(s)
CONTRACT_GRANT: NNG15HQ01C
Distribution Limits
Public
Copyright
Other