Laboratory measurements of polarization radios of wind wave surfaces

Polarization ratios (
\sigma_{vv}/\sigma_{HH}
) of wind-generated rough water surfaces are studied experimentally by means of radar backscatter power measurements. The measurements were made at 9.23 GHz with incidence angles between
45\deg
and
55\deg
for wind speeds between 3 m/s to 10 m/s. Scattering surface statistics at all wind speeds were also measured by means of a wave height gauge and a laser slope gauge. The polarization ratio data are presented against parameters pertinent to scattering theory, which are obtained from the measured surface statistics. The results are compared to "composite surface" theory calculations for an assumed wave-height spectral density of the form
F(k) \propto k^{-m}
, where
m
is an adjustable parameter.