BOREAL FOREST ECOSYSTEM CHARACTERIZATION WITH SIR-C XSAR/

This paper discusses early results obtained from Spaceborne Imaging Ra dar-C (SIR-C) and X-band synthetic aperture radar (XSAR) data over a b oreal forest in Saskatchewan, Canda. Multifrequency and multipolarizat ion image data were made available during the SRL-1 (Apr. 10, 1994) an d SRL-2 (Oct. 1, 1994) missions. These image data sets were analyzed a nd maps of forest cover type and above ground woody dry biomass were g enerated. A portion of the Southren Study Area of the Boreal Ecosystem -Atmosphere Study (BOREAS) was mapped for forest cover type with class ification accuracies on the order of 80%, Maps of estimated biomass we re also produced that match observed patterns and preliminary ground d ata, The upper limit of sensitivity of the radar to boreal forest biom ass in our study area was about 20 kg/m(2) or 200 tons/ha, The highest average observed biomass in our ground measurements was about 25 kg/m (2). Highest sensitivity of the radar to biomass was attained using Ap ril backscatter data and a ratio of L-band HV to C-band HV. Results sh ow that radar estimates of biomass were within +/- 2 kg/m(2) at the 95 % confidence level, A comparison of the April and October data sets wa s conducted to understand the effects of seasons on the analysis. It a ppears that the frozen trees and wetter background contributes to incr eased backscattering observed in the April data, These early results i ndicate that multiple polarization and multiple frequency SAR data can be used to monitor and map northern forest biomes.