# Lidar equation

From AMS Glossary

## lidar equation

An equation, which may appear in different forms depending on the particular system or application, that describes the relation between the received power

*p*measured in a lidar receiver channel from range*r*, and the characteristics of the lidar system and the transmission medium (usually the atmosphere) through which the laser pulse propagates.The most common form of the equation is for plane-polarized radiation and single scattering, for which where β is the volume backscattering coefficient at range Normally scattering and extinction of the lidar beam are caused by the combined effects of molecules, aerosols, and hydrometeors, so that β and γ represent the sum of their separate contributions.

*r,**t*^{2}is the two-way transmittance to range*r,*and*C*is the lidar constant, which depends on such system parameters as the transmitted power, pulse duration, and receiver characteristics. The transmittance is related to the volume extinction coefficient γ by*Compare*radar equation.