Simulation of L band horizontally copolarized radar backscattering coefficients using the integral equation model [70] for various values of volumetric soil moisture and rms surface roughness (cm). Surface correlation length has been taken as 8 cm, % sand = 30, and % clay = 30. For various roughness values, moisture versus backscatter curves can be approximated as straight lines with the same slope. L band vertically copolarized radar backscattering coefficients show a similar behaviour too [55].
