From Glossary of Meteorology
Hemispheric backscatter (also referred to as backscattering or backward scatter) is the scattering of radiant energy into the hemisphere of space bounded by a plane normal to the direction of the incident radiation and lying on the same side as the incident ray; the opposite of forward scatter. Atmospheric backscattering depends greatly on wavelength and polarization considered, as well as atmospheric composition, including the presence of aerosols, clouds, and precipitation.
In radar and lidar usage, backscatter refers only to that radiation scattered at 180° to the direction of the incident wave; the units of the backscatter coefficient, that is, the physical quantity used to describe the backscattering process, are m−1 sr−1 (per meter and steradian).
Term edited 15 June 2019.