The international reference ionosphere IRI (IRI-2001 and IRI-2007) model was tested on the basis of a large set of statistical data including the complete 23rd solar cycle. The data of total electron content (TEC) above the ocean surface deduced from measurements by dual-frequency satellite altimeters ("Topex"/"Poseidon" and "Jason-1") were used for the experimental test. It was found that the model TEC values are systematically less than those obtained experimentally by about 3 · 10 16 m −2 . It was shown that the rms deviation of the experimental data from the model shows almost linear dependence on the F10.7 index. The relative errors of IRI-2001 and IRI-2007 have significant 11-year and annual variations. The relative error of IRI-2001 against the altimeter data is less than 40% in 69% of the measurements and of IRI-2007, in 67% of the measurements. The diurnal variation amplitude of the absolute error stipulated by the difference of the model variation and the actual ionization increase during the dawn solar terminator passage is about 5 · 10 16 m −2 .

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This paper presents results of an experimental verification of the spectral-polarization method of measuring the interference pattern velocity by analyzing three mutually orthogonal projections of the radio signal field. The measurements were made on the HF radio path about 100 km in length. It is shown that the proposed method gives mean values of the azimuth and zenith angle which differ by less than 2-5 degrees from calculated values. Mean velocity values of travelling ionospheric disturbances (of order 50 m/s) and propagation directions (north-westvJard changing to northward by the morning hours) obtained for these time intervals are consistent with existing published data.