Characterization of surface radar cross sections at W-band at moderate incidence angles

From National Research Council Canada

DOIResolve DOI: http://doi.org/10.1109/TGRS.2017.2682423
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Name affiliation
  1. National Research Council Canada. Aerospace
TypeArticle
Journal titleIEEE Transactions on Geoscience and Remote Sensing
ISSN0196-2892
1558-0644
Volume55
Issue7
Pages3846–3859
Subjectdepolarization ratios; radar surface cross sections; radar theory; W-band
Abstract
This paper presents the results of a recent flight campaign conducted over the Great Lakes region and reports the first observations of the W-band normalized backscattered cross section (σ0) for V and H polarization and the linear depolarization ratios (LDRs) from different types of surfaces at moderate incidence angles (<;70°). For sea surfaces, while the observed σ0 behaves as previously reported at small incidence angles, it features a marked decrease with increasing incidence angles between 20° and 50°. There is a strong dependence of normalized backscattered cross sections both on the wind speed and on the wind direction, with larger values found in the presence of higher wind speeds and when the radar antenna is looking upwind. This is in line with theoretical models (though models tend to overpredict the range of variability at a given incidence angle) and with observations at lower frequencies. The LDRs are steadily increasing from values certainly lower than -30 dB, at vertical incidence, to the values of about -10 dB, at the incidence angles of about 60°-70°, with a good matching between observations and theoretical predictions. On the other hand, land surface backscattering properties are not characterized by a strong angular dependence: σ0 and LDR values typically range between -20 and 0 dB and between -15 and -5 dB, respectively. This paper is relevant for spaceborne concepts of W-band radars, which envisage moderate incidence angles to achieve a broad swath needed for global coverage.
Publication date
PublisherIEEE
LanguageEnglish
Peer reviewedYes
NPARC number23002636
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Record identifierab547411-23c4-46b7-8867-bf0dc058f6be
Record created2017-12-08
Record modified2017-12-08
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