Kitab as One of the Five Stations of the ILS: History and Present
Abstract
Abstract The Tashkent Astronomical Observatory (Ulugh Beg Astronomical Institute of the Uzbek Academy of Sciences since 1966) was involved to the International Latitude Service (ILS) in September 1899, when the regular latitude measurements were started at Tschardjui ( ϕ = +39°08′11″,λ = −63°29′). Because of the Civil War in Central Asia, the latitude observations were ended at Tschardjui in May, 1919. A new latitude station was established at Kitab (Uzbekistan) at latitude ϕ = +39°08′40″ and longitude λ= −66°53′, in November 1930. The Kitab Latitude Station was equipped with two visual zenith telescopes (1929, 1957) and the photographic zenith tube removed from the Pulkovo observatory in 1978. The Kitab station provided the ILS with more than 250000 instantaneous latitude measurements. Since the early 90s Kitab has hosted the ground-based beacons of GPS, PRARE and DORIS satellite tracking systems, providing the IERS data center with precise coordinates at sub daily frequency.