Peculiarities of microwave radiation from periodically uneven ground

Radiation from sporadically uneven ground is calculated by the method of matrix equations in the quasistatic approximation. It is shown that, if the amplitude of irregularities is less than 0.1 lambda, then the sign of the degree of polarization of the zenith radiation depends on the sign of the moisture content gradient in a layer of the thickness < 0.1<lambda>. It is demonstrated that the sign of the moisture content gradient can be determined by the sign of the degree of polarization; as a result, the accuracy of finding the moisture content of soil by the remote radiometric method can be enhanced.