Parameter Tree:
EARTH SCIENCE > LAND SURFACE > SURFACE RADIATIVE PROPERTIES > EMISSIVITY

Definition:
The ratio of the radiation emitted by a surface to the radiation emitted by
a perfect blackbody radiator at the same temperature.


Reference:
CCRS Remote Sensing Glossary
http://www.ccrs.nrcan.gc.ca/ccrs/eduref/ref/glosndxe.html