Turbulence spectrum and the solar wind velocity at elongations of 90-150 deg

Investigation results are presented for energy spectra of scintillations caused by inhomogeneitxes of the interplanetary plasma ionosphere in the decameter wave range. A possibility of their separation is shown. Scintillation spectra of radio sources at 12.6-25 MHz are of a power form with the spectral index 3.1+-0.6 for interplanetary scintillations and 3.4+-0.5 for ionospheric ones. When observing interplanetary scintillations for less than 2 h a marked frequency drift of the Fresnel filter cut off have not been detected. A spread of instantaneous spctra is due, mainly, to random fluctuations. Considerable frequency drifts of the Fresnel filter cut off are observed during measurements differed by more than a day. By a model of phase screen an estimation has been obtained for the effective velocity of the solar wind of 300+-80 km/s at elongations of 90-150 deg that is in good agreement with the data given elsewhere