The modern radio astronomy network in Ukraine: UTR-2, URAN and GURT

Abstract

International audienceThe current status of the large decameter radio telescope UTR-2 (Ukrainian T-shaped Radio telescope) together with its VLBI system called URAN is described in detail. By modernization of these instruments through implementation of novel versatile analog and digital devices as well as new observation techniques, the observational capabilities of UTR-2 have been substantially enhanced. The total effective area of UTR-2 and URAN arrays reaches 200 000 m2, with 24 MHz observational bandwidth (within the 8–32 MHz frequency range), spectral and temporal resolutions down to 4 kHz and 0.5 msec in dynamic spectrum mode or virtually unlimited in waveform mode. Depending on the spectral and temporal resolutions and confusion effects, the sensitivity of UTR-2 varies from a few Jy to a few mJy, and the angular resolution ranges from ~ 30 arcminutes (with a single antenna array) to a few arcseconds (in VLBI mode). In the framework of national and international research projects conducted in recent years, many new results on Solar system objects, the Galaxy and Metagalaxy have been obtained. In order to extend the observation frequency range to 8–80 MHz and enlarge the dimensions of the UTR-2 array, a new instrument – GURT (Giant Ukrainian Radio Telescope) – is now under construction. The radio telescope systems described herein can be used in synergy with other existing low-frequency arrays such as LOFAR, LWA, NenuFAR, as well as provide ground-based support for space-based instruments

Direct Observations of Traveling Ionospheric Disturbances as Focusers of Solar Radiation: Spectral Caustics

“…• URAN-2 (location: Stepanovka, Ukraine; coords: φ 0 = 49.63 • , λ 0 = 34.825 • ; frequency band: 8-33 MHz; aerial: phased array consisting of 512 elements)) (Konovalenko et al 2016);…”

Digital Receivers for Low-Frequency Radio Telescopes UTR-2, URAN, GURT

“…Such a high sensitivity, broad frequency band and interference immunity open the way for solving a number of astrophysical problems both on individual subarrays, and with full radio telescope in coordination with other LF radio telescopes (Konovalenko et al, 2016).…”

“…Conversely, lessons learned in digital receiver development and operation at a given telescope may be helpful elsewhere. This is the motivation that inspired the present paper, that brie°y reviews digital receivers developed for the Ukrainian LF radio arrays Ukrainian T -shaped Radio Telescope Version-2 (UTR-2), URAN, and Giant Ukrainian Radio Telescope (GURT) (Konovalenko et al, 2016), which have already delivered important astrophysical results. Section 2 describes the existing Ukrainian LF radio telescopes and those under construction with their successive generations of digital receivers.…”

“…It was followed by the UTR-2 (Braude et al, 1978, Fig. 1), the URAN-1 to −4 radio interferometer (Megn et al, 1997, 2003, and recently the¯rst sections of the new generation Giant Ukrainian Radio Telescope GURT, (Konovalenko et al, 2016, Fig. 3).…”

Book of Proceedings Tenth Workshop Primorsko, Bulgaria 2018

“…Each element of the array is an active antenna that should satisfy all the requirements for small-sized solar radio telescope listed above. Giant Ukrainian Radio Telescope (GURT) is a project of new-generation low-frequency radio telescope developed in Ukraine by Institute of Radio Astronomy of National Academy of Sciences of Ukraine (IRA NASU) based on the experience of UTR-2 radio telescope maintenance and upgrading [Ryabov et al, 2010;Konovalenko et al, 2016]. GURT operates in 8-80 MHz range and consists of separate subarrays of 25 active antenna elements.…”