The Allen telescopr array: Splitting the aperture

Abstract

Most science applications in radio astronomy require great sensitivity and, thus, large amounts of collecting area and a quality receiver. Decoupling of the resolution and sensitivity is done by splitting the aperture into many antennas, where one may choose the sensitivity (number of antennas) independently of the resolution (spacing of the antennas). The ATA will be nearly as sensitive as the most sensitive current radio telescopes because it will have a large collecting area, about 10,000 m/sup 2/. However, the ATA will be unusual in several respects: it will have a wide field of view (about 5 deg/sup 2/ at 1,420 MHz - for reference, the moon and Sun are each about 0.2 deg/sup 2/), continuous frequency coverage from 0.5 to 11.2 GHz (with simultaneous observations possible throughout the band), and a very large number of antennas. The technologies primarily enabling the ATA are low-cost ultra-wide-bandwidth analogue electronics and high-speed digital electronics, as well as "mid-quantity" production techniques.