Using spatial radio wave field processing for diagnostics of inhomogeneous plasma

We explore the possibilities of double and single spatial field processings, obtained using the method of double weighted Fourier transform (DWFT), for inhomogeneous plasma diagnostics. We focus on the problem of diagnostics of local small-scale plasma irregularities generating strong radio wave phase variations during small-angle scattering. Numerical calculations of wave phase in DWFT and phase screen approximations have shown that the use of double and single spatial field processings expands Fresnel resolution even in conditions of strong phase variations. However, the single field processing requires knowing coordinates of the virtual screen plane, used for the field processing. For optimal determination of this parameter, we suggest using an algorithm based on the synthesis of Fresnel inversion and DWFT method for remote irregularities. The combined use of the inverse Radon transform and double and single spatial field processings provided images of three Gaussian plasma irregularities with scales less than the Fresnel radius in conditions of strong wave phase variations. We analyze the effect of discretization of elements and size of a transmitting and receiving system on field processing.