An experimental study of a pulse compression scatterometer system

The ideal scatterometer, operating from either an aircraft or a satellite platform, should be capable of making rapid, accurate estimates of the sea backscatter cross section
\sigma
over as wide a range of grazing angles
\psi
as possible. Efficient operation over a large range of grazing angles is desirable because 1)
\sigma
behavior for
90\deg \geq \psi \geq 70\deg
yields rms gravity wave slope information and is an indicator of sea state and 2)
\sigma
behavior for
70\deg \geq \psi \geq 0\deg
yields data on surface wind magnitude and direction as well as information about the power spectrum of the sea. A "hybrid" estimation procedure has been developed for pulse compression radars which uses both frequency and spatially decorrelated samples of
\sigma
to provide an unbiased estimate of
\sigma
having minimum variance over the entire range of grazing angles for which radar reception is not noise-limited.