The Multi-Angel Imaging Spectrometer (MISR) instrument provided several images
of Hurricane Katrina. These views of the Louisiana and Mississippi regions were
acquired before and one day after Katrina made landfall along the Gulf of
Mexico coast, and highlight many of the changes to the rivers and vegetation
that occurred between the two views. The images were acquired by NASA's
Multi-angle ... Imaging SpectroRadiometer (MISR) on August 14 and August 30, 2005.
These multiangular, multispectral false-color composites were created using red
band data from MISR's 46" backward and forward-viewing cameras, and
near-infrared data from MISR's nadir camera. Such a display causes water bodies
and inundated soil to appear in blue and purple hues, and highly vegetated
areas to appear bright green. The scene differentiation is a result of both
spectral effects (living vegetation is highly reflective at near-infrared
wavelengths whereas water is absorbing) and of angular effects (wet surfaces
preferentially forward scatter sunlight).
[Summary provided by NASA/JPL.]