The Multi-angle Imaging SpectroRadiometer (MISR) was launced on board the National Aeronautic and Space Administration (NASA) Terra platform in December 1999. It makes simulataneous measurements of reflected solar radation at 9 widely spaced angles in 4 spectral bands in the blue, green, red and near-infrared. By making measurements at various angles the instrument provides improved discrimination of various aerosol types, cloud and surface features.