Plasma density evaluation in the sharply-bounded ionosphere model by tweeks

The work is devoted to the development of new radiophysical methods for diagnostics of the lower ionosphere by analyzing pulse signals of natural origin in the ELF - VLF frequency range propagating in the Earth - ionosphere waveguide - tweek-atmospherics (tweeks). The effective height of the first waveguide mode has been shown to be usually higher than the effective height of the second waveguide mode. That fact allowed to develop a new method for estimating the electron density in the ü-region of lower ionosphere by measuring cutoff frequencies of tweek signals in sharply-bounded ionosphere model approach. Experimental ensemble of three-component recordings of tweeks (vertical electric and two orthogonal horizontal magnetic components) was used for method testing.