CLARREO Pathfinder

CLARREO Pathfinder’s data will provide hyperspectral measurements of Earth-reflected solar radiation with an unprecedented SI-traceable radiometric uncertainty of 0.3%-0.6% (k=1) within a spectral range of 350-2275 nm with 3-nm spectral intervals.  These measurements will serve as an on-orbit reference for the intercalibration of other reflected solar instruments in space.

Objectives

The CLARREO Pathfinder mission has two principal objectives: 

• The first demonstrates on-orbit calibration methodologies achieving an unprecedented level of accuracy while maintaining traceability to SI standards. 
• The second objective showcases an innovative on-orbit intercalibration approach, wherein two other RS sensors—the shortwave (SW) channel of the Clouds and the Earth’s Radiant Energy System (CERES) and the Reflective Solar Bands (RSB) of the Visible Infrared Imager Radiometer Suite (VIIRS)—are intercalibrated against CLARREO Pathfinder benchmark measurements, with a targeted intercalibration methodology uncertainty of 0.3-0.6% (k=1). 

Leveraging the CLARREO Pathfinder payload's two-axis pointing capability, moderate spatial sampling resolution (0.5 km), and wide spectral coverage, the CLARREO Pathfinder instrument will enable near-simultaneous temporal, spatial, angular, and spectral matched observations with intercalibration targets.