How does surface roughness affect the look of my radar scene?
Surface roughness influences the reflectivity of microwave energy and thus the brightness of features on the radar imagery. Horizontal smooth surfaces reflect nearly all the energy which strikes their surface away from the radar and are described as specular (from the Latin world speculum, meaning mirror). Specular surfaces, such as calm water or paved highways, appear dark on radar imagery. Microwaves incident on a rough surface are scattered in many directions. This is known as diffuse or distributed reflectance. Vegetation surfaces will cause diffuse reflectance, and result in a brighter tone on the radar imagery. The stronger the return is, the lighter in tone the image will appear. The strength of the return is influenced by such terrain parameters as: the orientation of topographic features (local incidence angle,) surface roughness, thickness or volume of surface cover, and moisture content/dielectric properties. The return signal is also influenced by system parameters: inciden
