Comparison of in situ and satellite-derived reflectances of Forbindels Glacier, Greenland

In situ and Landsat Thematic Mapper (TM)-derived reflectances of the Forbindels Glacier, Greenland, were acquired in August of 1986. Reflectance was measured in situ using a portable spectrometer and calculated using TM data and ancillary information. Atmospheric corrections were applied to the at-satellite reflectances resulting in a 5-17 per cent increase in reflectance relative to the calculated at-satellite reflectances. The satellite-derived, corrected reflectances obtained from the non-saturated TM bands corresponded to within 6 per cent of the in situ reflectances measured at the nadir viewing angle with a portable spectrometer. Measurement of nadir reflectances using Landsat-TM data appears to be a viable method to obtain physically meaningful reflectances of ice and snow.