Measurement and behavior of dual-polarization vegetation optical depth and single scattering albedo at 1.4- and 5-GHz microwave frequencies

Abstract

A measurement procedure has been developed and tested to determine horizontal and vertical polarization radiative transfer properties, i,e., single scattering albedo (/spl omega/) and optical depth (/spl tau/), of vegetation under field conditions. The procedure was applied to a wheat crop for a series of biomass densities. The measurements were done using two different radiometers (1.4 and 5 GHz) and for different view angles. The measurements and calculations indicated that the ratios of horizontal and vertical polarization radiative transfer properties (/spl alpha/=/spl Gamma//sub h///spl Gamma//sub /spl nu//, /spl alpha/'=/spl tau//sub h///spl tau//sub /spl nu// and /spl beta/=/spl omega/h//spl omega//sub /spl nu//) are slightly dependent on view angle. However, no significant dependence on biomass density could be discerned.