In addition to radiometric, spatial, and spectral calibration requirements, MODIS design specifications include
polarization sensitivity requirements of less than 2% for all Reflective Solar Bands (RSB) except for the band centered
at 412nm. To the best of our knowledge, MODIS was the first imaging radiometer that went through comprehensive
system level (end-to-end) polarization characterization. MODIS polarization sensitivity was measured pre-launch at a
number of sensor view angles using a laboratory Polarization Source Assembly (PSA) that consists of a rotatable
source, a polarizer (Ahrens prism design), and a collimator. This paper describes MODIS polarization characterization
approaches used by MODIS Characterization Support Team (MCST) at NASA/GSFC and addresses issues and
concerns in the measurements. Results (polarization factor and phase angle) using different analyzing methods are
discussed. Also included in this paper is a polarization characterization comparison between Terra and Aqua MODIS.
Our previous and recent analysis of MODIS RSB polarization sensitivity could provide useful information for future
Earth-observing sensor design, development, and characterization.
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