Effect of Polarization on Radar Backscatter in Relation to Slash Pine Stand Biomass Using Aircraft and Sir-b Data

L-band multipolarized (i.e. HH, VV, VH and HV) multiple incidence angle aircraft Synthetic Aperture R~dar data were analyzed in relation to the biomass and other stand parameters (e.g. basal area, dI~me!er at breast hel~h~, tree height, and stand volume) for 35 slash pine plantations. The purpose was to detennme If there are statistIcally significant relationships between slash pine stand biomass ?r <?ther stand parat1?eters. and L-band (2~.5 .cm.) radar backscatter, and if so, to detennine the effect of radar polanzatIOn on such relatIOnshIps. The study site m northern Florida has very little topographic relief, thereby minimizing the effects of topography on the rad~ backscatter. The results show significant correlation between the cross polarized (e.g. HV and VH) and VV-polanzed radar data and biomass, as well as several of the other stand parameters. The correlation between the HH-polarized data and t~e sta~d parameters was very low. These results indicate that future Shuttle Imaging Radar Systems (e.g. SIR-C, WhiCh WIll have cross-polarized radar sensors) should be able to obtain better results in attempting to estimate forest biomass than were obtained with previous satellite radar missions which obtained only HHpolarized SAR data.