A LOW-FREQUENCY RADIO TELESCOPE AT MAURITIUS FOR A SOUTHERN SKY SURVEY

A new, meter-wave radio telescope has been built in the northeast of M auritius, an island in the Indian Ocean, at a latitude of -20.14 degre es. The Mauritius Radio Telescope (MRT) is a Fourier Synthesis T-shape d array, consisting of a 2048 m long East-West arm and an 880 m long S outh arm. In the East-West arm 1024 fixed helices are arranged in 32 g roups and in the South arm 16 trolleys, with four helices on each, whi ch move on a rail are used. A 512-channel digital complex correlation receiver is used to measure the visibility function. At least 60 days of observing are required for obtaining the visibilities up to 880 m s pacing. The Fourier transform of the calibrated visibilities produces a map of the area of the sky under observation with a synthesized beam width 4' x 4.6' sec(delta + 20.14 degrees) at 151.5 MHz. The primary objective of the telescope is to produce a sky survey in the declinati on range -70 degrees to -10 degrees with a point source sensitivity of about 200 mJy (3 sigma level). This will be the southern sky equivale nt of the Cambridge 6C survey. In this paper we describe the telescope , discuss the array design and the calibration techniques used, and pr esent a map made using the telescope.