Characteristics of the inner magnetosphere obtained from whistler observations

The paper presents estimates of the equatorial electron concentration, the total density in the intensity of whistler ducts, the interchange plasma fluxes between the magnetosphere and ionosphere, and the structural inhomogeneities in the regions of the whistler propagation. All data refer to L-shells about 2, on which the whistlers observed in Sofia propagate. The solar activity minimum during 1976-1977 influences values of the estimated magnetospheric parameters; differences of 30 to 50% were obtained when compared with the same parameters determined during increased and maximum solar activity.