Irkutsk Incoherent Scatter Radar: history, present and future

The article focuses on the history of ionospheric research using the incoherent scatter method at the Institute of Solar-Terrestrial Physics and development of the only incoherent scatter radar in Russia, which is located near Irkutsk. It describes the radar features and the current situation of research at the Irkutsk Incoherent Scatter Radar (IISR).Operating modes and types of measurements of the radar are specified. There is a brief description of the original measurement techniques that were developed considering the IISR features such as the frequency principle of scanning and receiving of one linear polarization of a scattered signal. The main feature of the IISR is the possibility of obtaining absolute values of the ionospheric plasma electron density. The automatic method for constructing the electron density vertical profile is based on registration of vertical profiles of a rotation phase of the polarization plane of a scattered signal. The method does not require calibration with additional facilities.