John Wessels, senior radar scientist for PCI Geomatics, discusses SAR polarimetry for flooded vegetation for LiDAR/SAR Wetland and Water Monitoring Workshop.
He discusses the difference between single polarization and three polarizations, explaining, for example, that single polarization gets data from the orientation of the antennae, but if you have three polarizations you are set on an orthogonal axis, which is essentially colour radar. The differences between single channel, dual channel, and the fully polarimetric are also discussed, and he introduces some basic scattering information. For instance, most natural targets are rough, and most artificial targets are smooth, and smooth targets have strong returns in HH and VV.
From the polarimetric image generated from the data, he talks about the significance of the red plane, green angle, and yellow angle. He compares polarimetric phase differences, and discriminators. He concludes that the scattering properties of wetlands can be measured by a fully 4-channel polarimetric radar. The polarimetric data contains a great deal of useful information about the scattering and structural characteristics of the terrain. It is important to consider that the interpretation of polarimetric radar data and derived variables, and decompositions require training.
This presentation was a part of the LiDAR/SAR Wetland and Water Monitoring Workshop at the Alberta Terrestrial Imaging Centre, in June of 2014.
