Near-field subsurface electromagnetic tomography and holography
Methods of multifrequency tomography and holography of subsurface dielectric inhomogeneities in the near-field zone based on the solution of inverse scattering problem are studied from the viewpoint of their applicability for targets with strong dielectric contrasts or with a complicated internal structure. Results based on numerical simulation with input data calculated from Maxwell equations are presented.
Inverse scattering problem in pseudopulse diagnostics of periodic structures
The dual regularization method is applied in the inverse problem of electromagnetic scattering to retrieve permittivity inhomogeneities in multilayer periodic dielectric structures by the pseudopulse synthesized from multifrequency reflectometry measurements. Based on the developed theory, the solution algorithm has been worked out and applied in the numerical simulation of this reflectometry diagnostics of inhomogeneities in multilayer structures of X-ray optics.
Ultra Low Frequency Sounding and Tomography of Earth Crust
Methods of the ultra low-frequency electromagnetic sounding of the conductivity into the earth crust based on wideband (in the frequency range 0.001-1000 Hz) measurements of electromagnetic fields using both natural and artificial sources of are considered. The inverse problem is solved to retrieve continuous one-dimensional profiles of conductivity using iterative approach for the non-linear integral equation derived from Maxwell's equations. A tomography method that uses many-frequency data of the 2D electromagnetic scanning along the earth surface is also proposed. The retrieval of the 3D structure of the conductivity in this method is based on the solution of the 3D integral equation that can be reduced to the convolution equation with respect to lateral co-ordinates in the frameworks of Born approximation