Investigation of the Irregular Structure of the Upper Ionosphere from the Interkosmos-19 Data

According to the topside sounding on board the Interkosmos-19 satellite the irregularities of the ionospheric plasma were investigated. The irregularities of different scales, from hundreds of meters to hundreds of kilometers were identified. The irregularities were observed in the auroral, sub-auroral, mid-latitude and equatorial ionosphere. Some of them are formed continuously, while others rarely, as a result of different disturbances. The irregularities features were investigated by the ray tracing, as well as singular spectrum analysis. The mechanisms of the irregularities formation are discussed.