Ulugh Beg Astronomical Institute (UBAI) of the Uzbek Academy of Sciences is the oldest scientific institution not only in Uzbekistan but in the whole Central Asia as well. It was founded as Tashkent Astronomical observatory in 1873 and reorganized to UBAI in 1966. It was known as an important astrometric center of the FSU. The photographic plate collection obtained with the Normal astrograph installed in Tashkent in 1895 and continued up to the mid of the 80s of the last century with Kitab double astrograph made by Zeiss is one of the richest in the world. Since the end of the 19th century UBAI was involved to the International Latitude Service. Kitab station of UBAI was one of five stations of the ILS network. Today Kitab is hosting the ground based beacon of the GPS satellite navigation system.
    At present the researches carried out in UBAI are mostly based on the observational data obtained at Maidanak astronomical observatory, located at a distance of 120 km south of the famous historical city of Samarkand. It lies on the spurs of the Pamir and Alai mountain system at 2700 m above the sea level. Maidanak observatory is unique due to its geographical location at the mid distance between the main astronomical facilities on the Canaries and the Hawaii as well as to its high quality atmospheric conditions. It makes Maidanak a very critical site for continuous monitoring of astrophysical objects.