Indian Astronomical Observatory, Hanle
The Indian Astronomical Observatory, the high-altitude station of IIA is situated at an altitude of 4500 metres above mean sea level to the north of Western Himalayas. Atop Mt. Saraswati in the vast Nilamkhul Plain in the Hanle Valley of Changthang, Ladakh (4250m above msl), the site is a dry, cold desert with sparse human population and the ancient Hanle monastery as its nearest neighbour. The cloudless skies and low atmospheric water vapour make it one of the best sites in the world for optical, infrared, sub-millimetre, and millimetre wavelengths.
A 2-m optical infrared telescope is installed at the observatory. This telescope is remotely operated from CREST, Hosakote, using dedicated satellite links. In addition, IIA is collaborating with University of Washington, St. Louis, in operating a 0.5-m photometry telescope for continuous monitoring of Active Galactic Nuclei. This telescope will be one of the pair of telescopes constituting Antipodal Transient Observatory. A 0.3-m Differential Image Motion Monitor, a 220-GHz radiometer and an Automated Weather Station have been installed to facilitate continuation of site characterisation. In addition to night observations, the site is also being characterised for solar observations.
The infrastructure developed by IIA at IAO, Hanle, has paved way towards initiating many new projects in astronomy such as the gamma-ray array telescope (HAGAR), jointly undertaken by IIA and TIFR, as well as in other paradigms of science.
The Hon'ble Chief Minister of Jammu and Kashmir, Dr Farooq Abdullah inaugurated the satellite communication link on Mt. Saraswati, Indian Astronomical Observatory, Hanle on June 2, 2001
The 2m telescope was dedicated to the nation on 29 August 2001 .