Wy. Tsai et al., Polarimetric scatterometry: A promising technique for improving ocean surface wind measurements from space, IEEE GEOSCI, 38(4), 2000, pp. 1903-1921
Citations number
35
Categorie Soggetti
Eletrical & Eletronics Engineeing
Journal title
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
Spaceborne wind scatterometers provide useful measurements of ocean surface
winds and are important to climatological studies and operational weather
forecasting. Past and currently planned scatterometers use measurements of
the copolarized backscatter cross-section at different azimuth angles to in
fer ocean surface wind speed and direction. Although successful, current sc
atterometer designs have limitations such as degraded wind performance in t
he near-nadir and outer regions of the measurement swath and a reliance on
external wind information for vector ambiguity, removal, Theoretical studie
s of scattering from the mind-induced ocean surface indicate that polarimet
ric measurements provide orthogonal and complementary directional informati
on to aid the wind retrieval process. In this paper, potential benefits of
making polarimetric backscatter measurements to improve wind retrieval perf
ormance are addressed, To investigate the performance of a polarimetric sca
tterometer, a modified version of the SeaWinds end-to-end simulator at the
Jet Propulsion Laboratory (JPL), Pasadena, CA, is employed, To model the ef
fect of realistic measurement errors, expressions for polarimetric measurem
ent variance and bias are derived. It is shown that a polarimetric scattero
meter can be realized with straightforward and inexpensive modifications to
a current scanning pencil-beam scatterometer system such as SeaWinds, Simu
lation results show that such a system can improve wind performance in the
nadir region and eliminate the reliance on external wind information. The m
echanism by which the addition of polarimetric measurements improves wind v
ector retrieval is discussed in detail. Field experiments are suggested to
better characterize the polarimetric scattering properties of the wind-modu
lated ocean surface for future applications to wind scatterometry.