Polarization and atmospheric backscatter coefficient measurements
Abstract
Recently, it was pointed out that polarization effects must be considered in hard target calibration of lidars. A vector theory of radiometry is developed, and it is demonstrated for a real nonideal target that the reflectance is a matrix quantity and not a scalar quantity, and that all its components must be measured. These concepts can be extended to actual field measurements of the volume backscatter coefficients. The volume backscatter coefficient at range R is an averaged (4 x 4) matrix, which is averaged over the sampling depth dR = c(tau)/2. The transmitted beam is polarized in a definite sense, the received beam is still polarized, and both are represented as (4 x 1) Stokes vectors so that the interaction must be represented by a (4 x 4) matrix called the volume backscatter coefficient. Present experiments are in error because data are considered scalar quantities with only one value, not a matrix with sixteen components. Some of these components may be zero, but many are not.
 Publication:

Applied Optics
 Pub Date:
 March 1989
 DOI:
 10.1364/AO.28.000865
 Bibcode:
 1989ApOpt..28..865A
 Keywords:

 Atmospheric Scattering;
 Backscattering;
 Optical Polarization;
 Optical Radar;
 Radar Targets;
 Scattering Coefficients;
 Atmospheric Optics;
 Calibrating;
 Polarized Light;
 Reflectance;
 Scalars;
 Optics;
 LIDAR;
 POLARIZATION;
 BACKSCATTERING