A two-dimensional fractional Brown motion (fBm) fractal model is presented,
which is suitable for describing the natural rough surface. Using the Kirc
hhoff approximation, the expressions of the electromagnetic scattering fiel
d and the normalized radar cross section from this fractal surface are obta
ined. Numerical results of the normalized radar cross section as a function
of the fractal dimension, characteristic length and incidence frequency ar
e given. Our fBm model is also compared with classical models of Gaussian a
nd exponential correlation.