Polarimetric Synthetic Aperture Radar Measurements of Snow Covered First-Year Sea Ice.
详细信息
- 作者：Hossain ; Md. Mosharraf.
- 学历：Master
- 年：2012
- 关键词：Three-component scattering model ; Snow cover ; First-
- 导师：Yackel,John J.,eadvisor
- 毕业院校：University of Calgary
- ISBN：9780494926369
- CBH：MR92636
- Country：Canada
- 语种：English
- FileSize：7646285
- Pages：116
文摘
This study examines the utility of fully polarimetric C-and SAR parameters and three-component scattering model to quantify the sensitivity of snow covered first-year sea ice FYI) to radar incidence angles and surface air temperature SAT) during the late winter transition. This three-component scattering model is based on surface,double-bounce and volume scattering contributed from various materials and surface properties. RADARSAT-2 C-band fully polarimetric synthetic aperture radar POLSAR) data is utilized to quantify the sensitivity of thermodynamic effects 8°； C and &minus； 0.4°； C) of the polarimetric backscatter signature on mean snow cover thickness ranging from 8 cm to 36 cm with in-situ geophysical data from four different validation sites along with two different radar incidence angles 29°； steep) and 39°； shallow) to discriminate between snow-covered smooth,rough and deformed FYI. The result shows enhanced discrimination at shallower incidence angles compared to steeper ones in both 2-D and 3-D plots. The double-bounce scattering contribution is low for all FYI types at both incidence angles which are attributed to shallower incidence angle as microwave energy being in direct contact with a greater volume of higher dielectric brine coated,enlarged snow grains in the basal layer compared to the steeper incidence angles. The results also show that surface scattering dominates for all three FYI types at both incidence angles and decreases with increasing surface roughness and radar incidence angles whereas opposite results observed for volume scattering mechanisms. The results indicate that higher variation measured for thin snow class &sim；7 dB for both co- cross-polarization backscatters compared to thick snow class &sim；1 dB which corroborates with electro-thermodynamic theory.