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CLARREO Approach for Reference Intercalibration of Reflected Solar Sensors: On-Orbit Data Matching and SamplingThe implementation of the Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission was recommended by the National Research Council in 2007 to provide an on-orbit intercalibration standard with accuracy of 0.3% (k = 2) for relevant Earth observing sensors. The goal of reference intercalibration, as established in the Decadal Survey, is to enable rigorous high-accuracy observations of critical climate change parameters, including reflected broadband radiation [Clouds and Earth's Radiant Energy System (CERES)], cloud properties [Visible Infrared Imaging Radiometer Suite (VIIRS)], and changes in surface albedo, including snow and ice albedo feedback. In this paper, we describe the CLARREO approach for performing intercalibration on orbit in the reflected solar (RS) wavelength domain. It is based on providing highly accurate spectral reflectance and reflected radiance measurements from the CLARREO Reflected Solar Spectrometer (RSS) to establish an on-orbit reference for existing sensors, namely, CERES and VIIRS on Joint Polar Satellite System satellites, Advanced Very High Resolution Radiometer and follow-on imagers on MetOp, Landsat imagers, and imagers on geostationary platforms. One of two fundamental CLARREO mission goals is to provide sufficient sampling of high-accuracy observations that are matched in time, space, and viewing angles with measurements made by existing instruments, to a degree that overcomes the random error sources from imperfect data matching and instrument noise. The data matching is achieved through CLARREO RSS pointing operations on orbit that align its line of sight with the intercalibrated sensor. These operations must be planned in advance; therefore, intercalibration events must be predicted by orbital modeling. If two competing opportunities are identified, one target sensor must be given priority over the other. The intercalibration method is to monitor changes in targeted sensor response function parameters: effective offset, gain, nonlinearity, optics spectral response, and sensitivity to polarization. In this paper, we use existing satellite data and orbital simulationmethods to determinemission requirements for CLARREO, its instrument pointing ability, methodology, and needed intercalibration sampling and data matching for accurate intercalibration of RS radiation sensors on orbit.
Document ID
20150019879
Acquisition Source
Goddard Space Flight Center
Document Type
Preprint (Draft being sent to journal)
Authors
Roithmayr, Carlos
(NASA Langley Research Center Hampton, VA, United States)
Lukashin, Constantine
(NASA Langley Research Center Hampton, VA, United States)
Speth, Paul W.
(NASA Langley Research Center Hampton, VA, United States)
Kopp, Gregg
(Colorado Univ. Boulder, CO, United States)
Thome, Kurt
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Wielicki, Bruce A.
(NASA Langley Research Center Hampton, VA, United States)
Young, David F.
(NASA Langley Research Center Hampton, VA, United States)
Date Acquired
October 29, 2015
Publication Date
March 3, 2014
Publication Information
Publication: IEEE Transactions on Geoscience and Remote Sensing
Publisher: IEEE
Volume: 52
Issue: 10
Subject Category
Earth Resources And Remote Sensing
Report/Patent Number
GSFC-E-DAA-TN22466
Distribution Limits
Public
Copyright
Public Use Permitted.
Keywords
radiometry
intercalibration
Data sampling
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