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International audience; Purpose: The results of studies of sporadic radio emission of several types of space radio sources, including neutron stars and planets of the Solar System, are presented. The aim of this work is to review the latest achievements in the study of low-frequency radio emission of the Solar System planets and transient signals similar to pulsar pulses using the UTR-2 radio telescope. The importance of the development of the verification methods of the spaceborne radio emission in the study of sporadic signals from various sources is shown. Design/methodology/approach: The studies of sporadic signals of different nature are based on the common set of procedures for cleaning records from the terrestrial radio frequency interference (RFI) in the frequency-time pattern using the information on the nature of the particular type of sporadic radio emission, possible types of interference and signal distortion. Characteristic features of sporadic radio emission of different sources are given, and for each of them the optimal method of signal extraction is developed. The efficiency of the developed procedures for cleaning from noise using adjustable parameters is shown. This is done on the basis of observations of diverse types of space radio sources, such as lightnings in the atmospheres of planets, single pulses of neutron stars and sporadic radio emission of Jupiter. Findings: The developed methods of signal extraction detection in the presence of radio-interference have allowed obtaining the unique results such as: the distribution of the total intensity of single pulses of neutron stars depending on the galactic latitude; the automatic search of lightnings in the Saturn’s atmosphere in data due to the carefully elaborated RFI mitigation procedures, which made it possible to obtain the Saturn electrostatic discharge (SED) emission parameters based on the most complete set of events. Increased efficiency of the selection of Jupiter’s S-radiation signals despite the data corruption by the presence of radio-interference, which was reached due to the carefully chosen parameters of data cleaning procedures, have allowed us to detect short and intensive bursts, being the most informative for determining the physical parameters of radio emission in the area of their generation. Conclusions: The large effective area and high sensitivity of the UTR-2 radio telescope allow making the sporadic radio emission study with high temporal and frequency resolutions. Due to these factors we can apply a wide range of methods of space signals’ detection in the presence of terrestrial radio-frequency interference of natural and artificial origin. The data cleaning parameters allow accounting for the characteristic features of space signals and to obtain important and even unique scientific results. Key words: decameter wavelength range; UTR-2; sporadic radio emission; transients; lightning in the atmospheres of planets; Jupiter S-bursts

Features of sporadic decameter solar radio emission associated with some active regions according to observations made with radio telescope UTR-2 on August 1, 2014 are considered. Analysis of characteristics of type IV bursts, fiber-bursts and type III bursts, which were preceded and followed by type IV bursts, was carried out. Similarity of origins of fiber-bursts and type III bursts. By the frequency drift rate, they are distributed by statistically independent groups. Each group of bursts and that of type IV bursts were identified with radio emission from a particular active region. The plasma parameters in these regions and their variations while generating type IV bursts are estimated. Key words: group of active regions, decameter wavelength range, type IV bursts, fiber bursts, type III bursts, identification, generation regions, plasma parameters Manuscript submitted 07.05.2014 Radio phys. radio astron. 2014, 19(4): 295-306 REFERENCES 1. BOISCHOT, A., 1958. Etude du rayonnement radioelectrique solairesur 169 MHz e l'aide d'un grand interferometre a reseau. Ann. d'Astrophys ., vol. 21, pp. 273. 2. GINZBURG, V. L. and ZHELEZNIAKOV, V. V., 1959. On the Possible Mechanisms of Sporadic Solar Radio Emission (Radiationin an Isotropic Plasma). Astron. Zh. (Sov. Astron), vol. 35, pp. 694–705. 3. MELNIK, V. N., RUCKER, H. O. and KONOVALENKO, A. A., 2008. Solar Type IV Bursts at Frequencies 10–30 MHz. In: PINGZHI WANG, ed. Solar Physics Research Trends. New York: Nova Science Pub., pp. 287–325. 4. ZAQARASHVILI, T. V., MELNIK, V. N., BRAZHENKO,A. I., PANCHENKO, M., KONOVALENKO, A. A., FRANZUZENKO, A. V., DOROVSKYY, V. V. and RUCKER, H. O., 2013. Radio seismology of the outer solar corona. Astron. Astrophys, vol. 555, id. A55. DOI: 10.1051/0004-361/201321548 5. MELNIK, V. N., KONOVALENKO, A. A., BRAZHENKO, A. I., RUCKER, H. O., DOROVSKYY, V. V., ABRANIN, E. P., LECACHEUX, A. and LONSKAYA, A. S., 2010. Bursts in emission and absorption as a fine structure of Type IV bursts. Astrophysics and Cosmology after Gamow: Proc. 4th Gamow International Conf. Astrophysics and Cosmology After Gamow and the 9th Gamow Summer School "Astronomy and Beyond: Astrophysics, Cosmology, Radio Astronomy, High Energy Physics and Astrobiology". AIP Conference Proceedings, vol. 1206, pp. 450–454. DOI: https://doi.org/10.1063/1.3292553 6. BOIKO, A. I., MELNIK, V. N., KONOVALENKO, A. A., ABRANIN, E. P., DOROVSKYY, V. V. and RUCKER, H. O., 2012. Decametric radio bursts associated with the 13 July 2004 CME event at frequencies 10–30 MHz. Adv. Astron. Space Phys. , vol. 2, no. 1. pp. 76–78. 7. BRAZHENKO, A. I., MELNIK, V. N., KONOVALENKO, A. A., ABRANIN, E. P., DOROVSKYY, V. V., VASHCHISHIN, R. V., FRANTZUSENKO, A. V. and RUCKER, H. O., 2010. Observations of the Solar Continuum Radio Emission at Decameter Wavelengths. Astrophysics and Cosmology after Gamow: Proc. 4th Gamown International Conf. Astrophysics and Cosmology After Gamowand the 9th Gamow Summer School "Astronomyand Beyond: Astrophysics, Cosmology, Radio Astronomy, High Energy Physics and Astrobiology". AIP Conf. Proc, vol. 1206, pp. 440–444. DOI: https://doi.org/10.1063/1.3292551 8. BRAUDE, S. Y., MEGN, A. V. and SODIN, L. G., 1978. Decameter wave band radio telescope UTR-2. In: Anteny . Moscow, USSR: Svyaz'. no. 26, pp. 3–14 (in Russian). 9. Student. The probable error of a mean. 1908. Biometrika , vol. 6. no. 1, pp. 1–25. 10. GOPALSWAMY, N., 2004. A Global Picture of CMEs in the Inner Heliosphere. In: G. Poletto and S. Suess, ed. The Sun and the Heliosphere as an Integrated system. Astrophys. Space Sci. Libr . Dordrecht: Kluwer Acad. Publ., vol. 317, pp. 201–250. DOI: https://doi.org/10.1007/978-1-4020-2831-1_8 11. HARTZ, T. R., 1969. Type III solar radio noise bursts at hectometer wavelengths. Planet. Space Sci. , vol. 17, no. 2, pp. 267–287. DOI: https://doi.org/10.1016/0032-0633(69)90044-0 12. MELNIK, V. N., KONOVALENKO, A. A., RUCKER, H. O., RUTKEVYCH, B. P., DOROVSKYY, V. V., ABRANIN, E. P., BRAZHENKO, A. I., STANISLAVSKY, A. A. and LECACHEUX, A., 2008. Decameter Type III like bursts. Sol. Phys. , vol. 250, no. 1, pp. 133–145. DOI: https://doi.org/10.1007/s11207-008-9166-z 13. MELNIK, V. N., KONOVALENKO, A. A., RUCKER, H. O., BOIKO, A. I., DOROVSKYY, V. V., ABRANIN, E. P. and LECACHEUX, A., 2011. Observations of Powerful Type III Bursts in the Frequency Range 10-30 MHz. Sol. Phys ., vol. 269, no. 2, pp. 335–350. DOI: https://doi.org/10.1007/s11207-010-9703-4