High frequency diagnostics on the CORONAS-I satellite

Quasi simultaneous data on High Frequency (HF) noise, antenna impedance and topside sounder were registered onboard the CORONAS-I satellite which operated in a nearly circular orbit of 500 km altitude and 82.5 deg inclination. Relevant details of the instrument operation are presented. We show the relevance of the equivalent circuit approach for identification of plasma density signatures in the noise and impedance data. Examples of onboard reduction of topside sounder data are presented. Examples of electron-density signatures extracted by onboard processing of impedance data and topside sounder data are shown. The advantages of integrated diagnostics for monitoring the plasma density are pointed out.