Small-scale ionospheric irregularities affect navigation and radio telecommunications. We studied small-scale irregularities observed during the 22 June 2015 geomagnetic storm and used experimental facilities at the Institute of Solar-Terrestrial Physics of the Siberian Branch of the Russian Academy of Sciences (ISTP SB RAS) located near Irkutsk, Russia (~52°N, 104°E). The facilities used were the DPS-4 ionosonde (spread-F width), receivers of the Irkutsk Incoherent Scatter Radar (Cygnus A signal amplitude scintillations), and GPS/GLONASS receivers (amplitude and phase scintillations), while 150 MHz Cygnus A signal recording provides a unique data set on ionosphere small-scale structure. We observed increased spread-F, Cygnus A signal amplitude scintillations, and GPS phase scintillations near 20 UT on 22 June 2015 at mid-latitudes. GPS/GLONASS amplitude scintillations were at a quiet time level. By using global total electron content (TEC) maps, we conclude that small-scale irregularities are most likely caused by the auroral oval expansion. In the small-scale irregularity region, we recorded an increase in the precise point positioning (PPP) error. Even at mid-latitudes, the mean PPP error is at least five times that of the quiet level and reaches 0.5 m.

The Irkutsk Incoherent Scatter Radar (IISR) allows us to carry out passive radio observations of the Sun and other powerful radio sources. We describe a method for absolute measurements of spectral flux density of solar radiation at IISR. The absolute measurements are meant to determine the flux density in physical units [W·m–2·Hz–1]. The IISR antenna is a horn with frequency beam steering, therefore radio sources can be observed at different frequencies. Also there is a polarization filter in the antenna aperture, which passes only single (horizontal) polarization. To acquire flux density absolute values, the IISR receiver is calibrated by the Cygnus-A radiation. Since the Sun’s position in the IISR antenna pattern is determined by a frequency differing from the Cygnus-A observation frequency, we perform an additional calibration of the frequency response in the 154–162 MHz operation frequency range, using the background sky noise. The solar disk size is comparable with the main beam width in the north—south direction, hence the need to take into account the shape of the brightness distribution in the operation frequency range. The average flux density of the quiet-Sun radiation was ~5 sfu (solar flux units, 10–22 W·m–2·Hz–1) at the 161 MHz frequency.

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The development of new devices for research in physics of the upper atmosphere and near-Earth space, which can be used to carry out controlled experiments on the modification of the ionosphere by powerful short-wave radiation, is an urgent task of modern solar-terrestrial physics, space weather, operation of satellite constellations in near-Earth space, radio communications, and radar. The paper describes a modern heating facility, created within the framework of the National Heliogeophysical Complex of the Russian Academy of Sciences. We review the tasks facing the heater, discuss its main technical characteristics, and describe the capability of the observational infrastructure surrounding the heating facility. The paper justifies the long-term benefits of the development of a heating facility at middle latitudes of Eastern Siberia, which can radiate in a frequency range 2.5–6.0 MHz with an effective power of the order of several hundred megawatts. It is important that the heater will be surrounded by such multifunctional instruments as the modern incoherent scatter radar, mesostratospheric lidar, observational systems that can provide a wide range of possibilities for diagnosing artificial plasma disturbances and artificial airglow structures.

Аннотация. В ближайшие годы в районе Иркут-ска планируется строительство радара, сочетающего в себе возможности радаров некогерентного рассея-ния (НР) и мезосферно-стратосферно-тропосферных радаров (МСТ) [Жеребцов и др., 2011]. Радар НР-МСТ представляет собой фазированную решетку, состоя-щую из двух разнесенных антенных полотен, с циф-ровой многоканальной приемной системой, позво-ляющей проводить детальную пространственно-временную обработку сигнала обратного рассеяния. Показаны характеристики, конфигурация и воз-можности антенной и приемопередающей систем радара. Оценивается потенциал радара в основ-ных режимах работы, включающих исследование ионосферы методом НР на высотах более ~100 км и изучение атмосферы с помощью сигналов, рассе-янных на флуктуациях показателя преломления, вызванных атмосферными турбулентными неод-нородностями, на высотах до 100 км.Моделирование показало, что радар позволит проводить регулярные измерения параметров нейтральной атмосферы на высотах до 26 км, а также наблюдать мезосферное летнее эхо на высотах ~85 км в присутствии заряженных ледяных частиц (при увеличении числа Шмидта) и мезосферное зимнее эхо на высотах ~65 км при повышении фоновой электронной концентрации. Оценка возможностей радара при работе в режиме НР в высотных диапазо-нах 100-600 и 600-2000 км показала, что в дневных условиях при накоплении 10 мин верхняя граница определения электронной концентрации и температу-ры ионосферной плазмы составляет ~1500 и ~1300 км соответственно при стандартном отклонении не более 10 %. Верхний предел определения скорости дрейфа составляет ~1100 км при стандартном отклонении 45 м/с. Оценка интерферометрических возможностей Abstract. In the next few years, a new radar is planned to be built near Irkutsk. It should have capabilities of incoherent scatter (IS) radars and mesospherestratosphere-troposphere (MST) radars [Zherebtsov et al., 2011]. The IS-MST radar is a phased array of two separated antenna panels with a multichannel digital receiving system, which allows detailed space-time processing of backscattered signal. This paper describes characteristics, configuration, and capabilities of the antenna and transceiver systems of this radar. We estimate its potential in basic operating modes to study the ionosphere by the IS method at heights above 100 km and the atmosphere with the use of signals scattered from refractive index fluctuations, caused by turbulent mixing at heights below 100 km.The modeling shows that the radar will allow us to regularly measure neutral atmosphere parameters at heights up to 26 km as well as to observe mesosphere summer echoes at heights near 85 km in the presence of charged ice particles (an increase in Schmidt number) and mesosphere winter echoes at heights near 65 km with increasing background electron density. Evaluation of radar resources at the IS mode in two height ranges 100-600 and 600-2000 km demonstrates that in the daytime and with the accumulation time of 10 min, the upper boundaries of electron density and ionospheric plasma temperature are ~...