Combination of target scattering decomposition with the optimum degree of polarization for improved classification of boreal peatlands in the Athabasca region

摘要

Target scattered wave polarization signature is introduced for the representation of the variations of the main scattered wave parameters as a function of the transmitting antenna polarization. It is shown that the signature of the degree of polarization (DoP) and the total scattered intensity (R) provide important information that is complementary to the Van Zyl conventional received intensity polarization signatures. As a result, the DoP optimization is used as an additional source of information in complement with target scattering decomposition for optimum characterization of peatlands and their surrounding upland forests. The study is conducted using polarimetric L-band PALSAR data collected over boreal peatlands in the Athabasca oil sand exploration region (near Fort McMurray, Alberta). The potential of polarimetric L-band PALSAR and the Touzi decomposition for monitoring water flow beneath the peat surface is confirmed. The scattering type phase permits an enhanced discrimination of poor fen from bogs; two wetland classes that can hardly be discriminated by optic and conventional SAR sensors. The complementary information provided by the DoP optimization permits better discrimination of burned from healthy forests. The DoP dynamic range as well as the scattering phase, which is sensitive to peatland subsurface water flow, permit the right assessment of peat health in burned black-spruce bogs.