Atmospheric extinction and scattering effects on laser rangefinders at eyesafe wavelengths

摘要

Abstract: Extinction of laser rangefinder (LRF) pulses by the atmosphere depends on the LRF wavelength, weather conditions, and the aerosol concentration along the optical path. The total atmospheric extinction $alpha@($lambda@) is the sum of the molecular and aerosol contributions, $alpha$-m$/($lambda@) and $alpha$-a$/($lambda@). We present simple expressions for $alpha$- m$/($lambda@) and $alpha$-a$/($lambda@) for the LRF sources: Er:glass, Ho:YAG, and CO$-2$/ which operate near 1.54, 2.1, and 10.6 $mu@m respectively. Also included are results for Nd:YAG which may be made to lase at the eyesafe wavelength of 1.444 $mu@m. The expressions give an estimate of $alpha@($lambda@) as a function of standard meteorological parameters, assuming horizontal beam propagation. The effect of forward scattering on the received LRF signal is also discussed. !23