The surface correlation length, denoted by l, is defined as the displacement ξ at which the surface correlation function p(ξ)= 1/e. Thus, l can be seen as the reference length up to which two points of one soil surface can be regarded as statistically independent from each other. If we imagine a perfectly smooth soil surface, l=∞ since every point on that surface correlates with all other points and can therefore be regarded as dependent from each other. As roughness depends not only on the soil surface properties but also the wavelength λ of the electromagnetic signal, the roughness parameters are scaled by the wave number k. Hence, the electromagnetic roughness kl for surface roughness parameter l is kl=(2π/λ)*l. Experimental results indicate a weaker influence on the radar backscatter compared to the RMS height s.
Discuss what horizontal roughness component (correlation legth) is
Completed