Forest type discrimination using calibrated C-band polarimetric SAR data

Abstract

To promote the unique polarimetric capability of RADARSAT-2, the Canada Centre for Remote Sensing (CCRS) has investigated the potential of fully polarimetric C-band synthetic aperture radar (SAR) for forest type discrimination. Six forest types in the Mer Bleu region of eastern Ontario were considered in this study: mixed forest, poplar, red pine, white pine, a mixed forest of red and white pines, and white spruce. Multi-date and multiple incidence angle acquisitions were acquired over the study site with the Convair-580 polarimetric SAR under leafy (summer) and no-leaves (winter) conditions. In addition to the conventional linear polarizations, HH, HV, and VV, various polarimetric discriminators, which were synthesized from the scattering matrix measurements, were investigated. It is shown that the radiometric intensity of the conventional C-band SAR polarizations HH, HV, and VV can only perform a limited discrimination of various tree species. The polarization information provided by fully polarimetric SARs clearly improves forest type discrimination under leafy and no-leaves conditions and permits the demonstration of the significance of SAR illumination angle on forest scattering mechanisms.