Imaging Plasma Inhomogeneities Using Spatial Wave Field Processing with DWFT Approximation

To analyze inhomogeneities, it is appropriate to use phase tomography, which is based on the measurement of the phase of a wave transmitted from a transmitter to a receiver. Physical parameters of inhomogeneous media are identified by these methods in several stages. At the first stage, a receiving system with antennas registers the phase of a wave scattered by an inhomogeneity. Then, depending on the type of tomographic measurements, an optimal method of computer tomography is selected. The final stage is to find the required physical parameter of the inhomogeneous medium. However, through diagnostics of inhomogeneous plasma by standard methods of ray and diffraction tomography it is not always possible to determine parameters of the medium. To obtain more accurate diagnostic results for the inhomogeneous medium, we can use additional processing of measurements. In this paper, we explore the possibility of reconstructing physical parameters (dielectric permittivity of the medium) of local plasma inhomogeneities with scales smaller than the Fresnel radius using the single spatial wave field processing and the approximation of the double weighted Fourier transform (DWFT). We study the influence of the processing plane location on the quality of recovery of physical parameters of the inhomogeneities.