POLDER2/ADEOSII, MISR, and MODIS/Terra reflectance comparisons

Reflectance differences among Multiangle Imaging Spectroradiometer (MISR), Moderate Resolution Imaging Spectroradiometer (MODIS)/Terra and Polarization and Directionality of the Earth’s Reflectances (POLDER2) are characterized, as functions of observation geometry and spectral bands. For observations having similar geometry, corresponding normalized reflectances from MISR and MODIS fall within 3% for all bands except the MISR red band, which is higher than MODIS and POLDER2 by about 3.5%. POLDER2 and MODIS are within less than about 1% in the blue and red, 4% in the near-infrared, and 5% in the green. Generally, MISR reflectances are at the high end of the reflectance envelope, whereas POLDER2 tends to be at the low end, yielding a spread of about 5% in the red, 5% in the near-infrared, and over 7% in the green. Reflectance differences were not quantitatively corrected for instrument-to-instrument spectral band pass differences because of the uncertainties associated with such calculations. However, these uncertainties are assessed, and the envelopes can be used to bound calibration contributions to derived geophysical quantity uncertainties, including aerosol amount and type. This is of particular importance when data from the three instruments are used together in geophysical applications.