Experimental characterization of the radar backscatter response of natural surfaces at 222 GHz

This paper examines recently measured polarimetric radar backscatter data of different types of bare and vegetation-covered surfaces at 222 GHz. Bare surfaces, such as asphalt, dirt, and concrete, are electrically rough with aggregate sizes comparable to the wavelength. This results in substantial volume and surface scattering. The data show strong angular dependence of the backscatter response from bare surfaces and significant depolarization between -8 dB and -4 dB. The data for vegetation-covered surfaces show weak dependence on incidence angle with appreciable depolarization between -12 dB and -6 dB.