The giant meterwave radio telescope

Abstract

The Giant Metrewave Radio Telescope(GMRT), which will be the most sensitive radio telescope facility in the world in the 30-1500MHz frequency range, is at an advanced stage of construction 80kms north of the city of Pune in India. GMRT will consist of 30 fully steerable parabolic dishes, of 45m diameter each. Twelve antennas form a random array in a central 1km × 1km area and the remaining 18 are equally distributed along the 3 arms of an approximate 'Y' configuration resulting in a maximum baseline separation of about 25km. GMRT will initially operate at six frequency bands around 50, 150, 233, 327, 610, and 1420 MHz. Low noise amplifiers are fitted at the back of each feed near the focus to keep the sensitivity high. Analog wideband optical fibre links connect all the antennas, for distributing local oscillator, intermediate frequency, telemetry and voice communication signals. An 'FX' correlator system will provide a total of 238,080 complex channels inculding 256 spectral channels for each of the 435 baselines and the self correlation products.