URAN

{{about|the radio-telescope|other uses|uran (disambiguation)}}

{{Infobox observatory}}

URAN (Ukrainian Radio Interferometer of NASU){{Cite journal|last=Konovalenko|first=A.|last2=Sodin|first2=L.|last3=Zakharenko|first3=V.|last4=Zarka|first4=P.|last5=Ulyanov|first5=O.|last6=Sidorchuk|first6=M.|last7=Stepkin|first7=S.|last8=Tokarsky|first8=P.|last9=Melnik|first9=V.|date=2016-04-28|title=The modern radio astronomy network in Ukraine: UTR-2, URAN and GURT|journal=Experimental Astronomy|language=en|volume=42|issue=1|pages=11–48|doi=10.1007/s10686-016-9498-x|issn=0922-6435|bibcode = 2016ExA....42...11K }} (Ukrainian: Український Радіоіонтеферометр Академії Наук - УРАН) is an array of radio-telescopes, spread across Ukraine and used for long-baseline interferometry in the 8-40 MHz range. The most sensitive of the telescopes is UTR-2; URAN-1 (built in 1975 in Zmiiv (Kharkiv oblast) ) and URAN-2 (construction started in 1979 in Stepanivka village near Poltava), URAN-3 is near Shatsk, in the north-west corner of Ukraine by the point where Poland and Belarus meet Ukraine, and URAN-4 (built in 1975) is in the south-west, a little west of Odesa and by the Moldovan border.

Auxiliary telescopes are URAN-1 has 96 dipoles in a 178 x 28m array; URAN-2 has 512 in a 238 x 118m; URAN-3 has 256 in a 238 x 58m; URAN-4 has 128 in 238 x 28m. Because of the small number of baselines, images from URAN tend to be produced by model-fitting to sums of Gaussians rather than by direct synthesis.

File:UTR-2, GURT, and URAN arrays on the map of Ukraine.png|URAN low-frequency VLBI system, UTR-2 and GURT radio telescopes on the map of Ukraine.

File:URAN Radio telescopes.png|Geometrical configurations of the individual dipole antennas of the four URAN radio telescopes