Stanislavsky, A.A., Koval, A.A., Bubnov, I.N., and Brazhenko, A.I. Progress in the study of decameter-wave- length solar radio emission with Ukrainian radio telescopes. Part 2. (Invited paper)

Abstract

Subject and Purpose. This part of the paper continues presentation of results of the solar radio emission studies performed with Ukrainian radio telescopes over the past 20 years. The importance is stressed of developing adequate instruments and methods for identifying the nature of decameter-wavelength radio emissions from the Sun. Methods and Methodology. The low frequency Ukrainian radio telescopes UTR-2, GURT and URAN-2 have been used in the project along with other ground- and space based instruments in order to achieve a comprehensive understanding of physical conditions in the solar corona. Results. Special methods and tools have been developed for studying radio frequency burst emissions against the background of strong interference. Unique data have been obtained concerning sources of sporadic radio emissions from the Sun, as well as the contribution from wave propagation effects and the impact of the ionosphere on the results of observations. The most significant observational and theoretical results are presented, obtained in the study of solar low frequency emissions over the past 20 years. Solar radio emissions are shown to be efficient sounding signals not for the solar corona alone but for the Earth’s ionosphere as well, which allows identifying its impact on the results of radio astronomy observations. Conclusions. The Ukrainian radio telescopes of the meter and decameter wavebands currently are unrivalled tools for investigating the Universe in the low-frequency range of radio waves. Owing to their advanced characteristics, they make a significant contribution to the progress of world’s solar radio astronomy.