Polarimetric Synthetic Aperture Radar Measurements of Snow Covered First-Year Sea Ice

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 sca...

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Bibliographic Details
Main Author: Hossain, Md. Mosharraf
Other Authors: Yackel, John
Format: Master Thesis
Language:English
Published: Graduate Studies 2012
Subjects:
Physical Geography
Physical Oceanography
Remote Sensing
Engineering > Marine and Ocean
Microwave
Polarimetric SAR
Snow Cover
First-Year Sea Ice
Sea ice
Online Access:http://hdl.handle.net/11023/252
https://doi.org/10.11575/PRISM/27377
Description
Summary: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 -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 ~7 dB for both co- cross-polarization backscatters compared to thick snow class ~1 dB which corroborates with electro-thermodynamic theory.

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