Multi-frequency SAR observation over forested areas has been the subject of research owing to the
frequency dependence on the contribution of radar backscatter from different parts of the vegetation
canopy. The multi-frequency SAR data at P-, L-, C- and X-band was acquired over Rajpipla site (Gujarat).
All the channels were in quad-pole mode except X-SAR, which was in HH and VV-polarization mode.
The study area comprises of the dry and moist deciduous forest. The moist deciduous forest is not
evergreen and shed their leaves during March-April. Teak (Tectona grandis) is the dominant species in the
moist deciduous forest area. Dry deciduous trees are mainly khakhar (Butea monosperma). Multifrequency
SAR data was processed to get geo-referenced images and all the images were co-registered.
Images were converted to the backscattering image using the calibration function. For the purpose of
ground verification, ground data was obtained at different locations. Ground data consisted of
measurements on tree height, diameter at breast height, basal girth, crown diameter etc. for each location;
measurements were done in 10m by 10 m area. The analysis of the data was carried out in relation to
comparison of backscattering coefficient in different frequencies and polarizations. In general, forest type
was better seen in X-band image as compared to other classes. However, X- and C-band could be
comparable in terms of forest classes. Further, backscattering coefficient increases with frequency except in
P-band. However, P-band showed best correlation with biomass as compared to other channels.