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