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The development of methods for the radio frequency interference mitigation becomes a fundamental challenge for any radio astronomy research. In this paper, we report on the development and creation of a new spectrometer designed for solar observations at the RATAN-600 radio telescope, capable of excising radio interference using a statistical algorithm based on the spectral kurtosis estimation. The implementation of the external analog interface and the operation of the digital signal processing system based on the FPGA are described. The maximum spectral resolution reached is 122 kHz in the frequency band of 1.0–3.0 GHz. The output spectrum has from 64 to 8192 frequency bins, depending on the requirements of the observer, the output rate is 120 spectra per second. The test results and the first observations of the Sun show that the research method can successfully detect and suppress interference from most of the local radio interference sources. [ABSTRACT FROM AUTHOR]

Modern studies of solar radio emission are complicated by continuous power amplification and multifrequency external interference, which often completely overlap important frequency ranges. Many topical problems in solar radio astronomy require large effective areas of radio telescopes, high frequency and time resolutions, accurate spatial measurements, and a large dynamic range. It becomes relevant to change the concept of receiving recording equipment. This paper deals with topical problems of the physics of the solar corona in combination with optimal methods of observation with large instruments. The features and difficulties of combining high parameters—dynamic, spatial, temporal, and frequency resolutions—are considered. The proposed solutions of the new-generation observation complex implement the possibilities of intelligent selection of registration conditions in a multioctave mode with multichannel over 8000 channels/GHz with temporary permission up to 8 ms/spectrum. A multiobject observation mode becomes available from powerful flaring objects to faint structures of various nature. High-speed data processing makes it possible to implement an online mode of interference elimination, which is based on a fast statistical analysis of the spectrum with the selection of non-Gaussian (interference) structures. Methods for high-speed analysis of large-volume data (the principal component analysis method) and their presentation to the user are proposed. Examples of the operation of the complex in the range of 1–3 GHz are given. The prospects of a new approach for multiobject radio astronomy observations in the implementation of the RATAN-600 tracking mode are considered: from recombination lines to wide-range spectra, from low-contrast fluctuations to fast changes in flares, etc. [ABSTRACT FROM AUTHOR]

There is a need today to recreate the Havana observational solar station because of the importance of obtaining a regular forecast of solar activity in a wide range of time intervals. The concept of the created observation network and the infrastructure of the monitoring station as a network element are described in detail. The functions of this network will provide continuous observational material for the Russian Sun and Space Weather Services and will be independent of space observations, but capable of using them for quality control. The physical foundations of complex observations for a wide range of heliogeophysical phenomena are considered. [ABSTRACT FROM AUTHOR]

The results of long-term mesoscale observations in the microwave range are reviewed. The rationale for the resumption of observations at the Havana Radio Astronomy Station is justified. Domestic observations at a wavelength of λ5 cm have a long observation interval and can effectively complement the global series of observations. A comparative analysis of the results of solar observation in the radio range and satellite observations in the UV and X-ray range is performed. The value of continuous observations for the assessment of space weather factors is shown. [ABSTRACT FROM AUTHOR]

We present the results of forecasting flare activity based on the data from microwave spectropolarimetric observations of active regions (ARs) obtained with the RATAN-600 radio telescope and the X-ray data from the GOES satellite as well as monitoring data. The method is designed for short-term (1-3-days) flare forecasts. Proton events are considered as part of the general flare problem. Obtaining a reliable forecast is a difficult process in view of the multi-parameter and multi-dimensional system of plasma parameter variations and multiple non-linear interconnections.We used a modified Tanaka-Enome criterion, as well a database of observational material collected over many years. The forecasting efficiency was analyzed depending on the threshold values of the criterion. We show that the quality of the radio astronomical forecast is determined by the level of sensitivity of the detector at short centimeterwavelengths and by the solar activity level. [ABSTRACT FROM AUTHOR]

The observations of the solar radio emission on September 11, 2001, with the RATAN-600 radio telescope (southern sector) at four centimeter wavelengths (1.92, 2.24, 2.74, and 3.21 cm) revealed synchronous brightenings in solar radio sources. These were identified on the solar photosphere with active regions that were spaced up to ∼106 km apart (AR 9608 and AR 9616). We discuss manifestations of the possible mechanisms of synchronous brightenings in solar sources in a narrow microwave spectral band. The significant linear correlation (ρc = 0.84–0.92) between the relative fluxes of AR 9610 and AR 9608 at 1.92 and 2.24 cm and the significant linear correlation (ρc = 0.65–0.84) between the relative fluxes of AR 9606 and AR 9608 at 3.21 cm in a two-hour interval of observations are indicative of the interconnection between these active regions not only during flares and bursts, but also in the periods of their absence. This confirms the existence of a large-scale temporal component in the dynamics of the radio flux variations for these active regions. We found a difference between the temporal variations of the radio emission from the halo and the solar radio sources under consideration. The times of increase in the total solar soft X-ray (0.5–4.0 Å, 1.0–8.0 Å; GOES 8, GOES 10) flux are shown to coincide with the times of increase in the fluxes from the solar radio sources at short centimeter wavelengths. © 2004 MAIK “Nauka / Interperiodica”. [ABSTRACT FROM AUTHOR]