Preliminary Report on Measurements of Forest Canopies with C-Band Radar Scatterometer at NASA/NSTL

This paper presents preliminary results of C-band radar scatterometer measurements of forest canopies of southeastern forests in the vicinity of NASA/NSTL. The results are as follows: 1) radar backscattering coefficients (BSC's) of deciduous forests such as oak, maple, blackgum, and cypress are higher than those of coniferous forests such as slash pine plantation and natural pine; 2) at a large incidence angle, where polarization effect is significant, and by ranging measurement, the VV polarization BSC's obtain peak value at the first few meters from the canopy top and decrease rather quickly, while the HH polarization BSC's obtain peak value at longer distances from the canopy top and decrease rather slowly through the canopy; 3) using the active radar calibrator for tree canopy attenuation measurement of a dense and a sparse live oak, it is found that the tree canopies with higher attenuations have higher BSC's for all three polarizations, with VV polarization containing the largest differential (2.2 dB).