The decrease in the intensity of a signal, beam, or wave as a result of the absorption of energy (by the terrain or medium over which, or through which, the energy travels) and of scattering out of the path to the detector but not including the reduction as a result of geometric spreading. Attenuation is usually expressed in dB (decibles). The term is often used as a misnomer for attenuation coefficient, which is expressed in dB per kilometer.
