CLARREO (CLimate and Absolute Radiance and Refractivity Observatory) Pathfinder Mission and Its Use of Polarization Distribution Maps for Intercalibration.

One of the most critical issues for current climate change
observations is their lack of accuracy and low confidence in observing
trends over decadal scales. In order to make highly accurate decadal
change observations traceable to SI standards on-orbit, the Climate
Absolute Radiance and Refractivity Observatory (CLARREO) mission was
first proposed in 2010. In 2016 the CLARREO Pathfinder technical
demonstration mission has passed the Mission Concept Review. The
CLARREO Pathfinder is a reflected solar spectrometer, whose goal is to
demonstrate, for the first time for the on-orbit measurements,
SI-level accuracy in calibration (target reflectance uncertainty under
0.3%, at k = 1), in order to measure scene spectral reflectance with
unprecedented accuracy. The second objective is, based on this
accuracy, to provide a reference calibration for other spectrometers
on orbit, such as CERES and VIIRS. We will provide an overview of the
CLARREO Pathfinder instrument, as well as its goals. We will also
describe in detail how the Pathfinder mission would correct the VIIRS
instrument measurements for polarization effects.