Scintillation spectra of ionospheric inhomogeneities and interplanetary plasma and possibility of their separation in decametric wavelength range

It is shown that in the decameter range scintillations on inhomogeneities of interplanetary plasma stand out against the background of ionospheric oscillations. Energy spectrum of interplanetary scintillations for 90-150 deg elongations in the range of 12.6-25 MHz has a power form with 3.1+ 0.6 spectral index which agrees well with its values for smaller elongations. Given is an evaluation of projection of solar wind rate for 110 deg elongations which is equal to 300+-80 km/s. As for smaller elongations, dispersion of rates is considerable. In the decameter range observed are wide-band spectra of ionospheric oscillations with break frequency near 0.01 Hz at 12 m wave length and narrowband spectra, break frequency of which is lower than 0.01 Hz. Spectrum of ionospheric oscillations has a power form with 3.4+-0.5 spectral index, but sometimes observed are steeper spectra