“…In our studies of the near-field subsurface microwave diagnostics, it was first used in passive radiothermometry [ 23 , 24 ] (for details see [ 25 ]) and later in various methods of the active microwave tomography of subsurface dielectric inhomogeneities [ 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ]. In these papers, methods of tomography and holography (for solid targets) of 3D subsurface inhomogeneities of permittivity were worked out and studied experimentally [ 26 , 27 , 28 , 29 , 30 , 31 , 33 ]. Additionally, methods of profiling 1D inhomogeneities were developed in papers [ 30 , 31 ].…”