The L-band data display a better separation between the GSw and
GAd classes, with median GSw σ0 values approximately 3 dB higher
than GAd for both HH and HV polarisations. Wet grasslands typically
have a higher soil moisture content compared to improved grasslands
which may be responsible for the increased backscatter. As expected,
the HV signals are weaker than the HH but the variations in median
σ0 of the grasslands display a similar pattern. As attenuation of microwave signals is greater in areas with increased canopy cover, the contribution from these scattering mechanisms is progressively reduced
during the vegetation growth stages. This is observed in the lower median σ0 values obtained for the summer L-band HH datasets (Fig. 3(c) &
(e)) and less clearly for some of the summer C-band acquisitions
(Fig. 3(a) & (b)). The analysis of the temporal backscatter profiles confirms the possibility to separate between the grassland classes using a
combination of C- and L-band acquisitions and different polarisations