# Range attenuation

From AMS Glossary

## range attenuation

In radar terminology, the decrease of power density with range in accordance with the inverse-square law as a result of the divergence of the beam.

For one-way transmission, this attenuation is proportional to 1/

*r*^{2}where*r*is the range from the antenna. For a monostatic radar and a point target, the range attenuation is proportional to 1/*r*^{4}because the beam diverges on the outward path and the return path. For monostatic radar and a distributed target, the range attenuation varies between these two limits, depending on the extent to which the pulse volume is filled with precipitation or other scatterers. Range attenuation only arises from the spreading of the attenuation with distance and should not be confused with attenuation caused by scattering and absorption.*See*radar equation, beam filling, range normalization.