Multifrequency microwave monitoring of water diffusion in soil

Possibilities of the monitoring the water diffusion into soil by data of multifrequency microwave measurements of the dynamics of complex amplitudes of the signal scattered by such an inhomogeneous medium are considered. Measurements have been carried out at 801 frequencies in the range (1.7...7) GHz using the vector network analyzer Agilent E5071B. In the experiment, the initial homogeneous over transversal co-ordinates near-surface water content distribution was prepared by uniformly spilled water, so following diffusion was described by the dynamics of the depth profile of the volume water content in soil. Transformation of multifrequency data to the complex-valued pseudopulse makes it possible to obtain a quality visualization of diffusion. The inverse problem of the retrieval of the depth profile evolution of the water content in soil has been solved by these data using the reduction of the problem to a one-dimensional Fredholm integral equation of the 1^st kind with the kernel function that has been obtained experimentally.