Differentiation between cloud cover and snow surfaces using remotely sensed data is complicated by the similarity of their radiative temperatures, and also by their similar reflectanccs at visible wavelengths. A method of cloud analysis over snow-covered regions is presented, using 1.51 – 1.63 μm data from an experimental sensor on board a U.S. Air Force Defense Meteorological Satellite Program platform. At these wavelengths, snow appears relatively ‘black’ while clouds are highly reflective. The spatial structure of the 1.51-1.63 μm reflectivity fields over a continuous snow surface are examined. Plots of mean reflectance against coefficients of variation for 4×4 pixel areas reveals a cluster of points have low reflectivity and low variability, corresponding to snow-covered (cloud free) areas, and a similar cluster with high reflectances corresponding to 100 per cent cloud cover. For the case of a single layered cloud, the radiances associated with partially filled fields of view are also inferred.
All Science Journal Classification (ASJC) codes
- Earth and Planetary Sciences(all)