(Australia Telescope National Facility; ATNFAT) A radio telescope combining the principles of aperture synthesis and long baseline interferometry (LBI). Run by Australia's CSIRO, the AT produced its first image in April 1989. There are eight antennas in all, at three sites in New South Wales. Six 22-meter dishes at the Paul Wild Observatory, Narrabri, form the Compact Array. Five of these are movable along a 3-km railroad track, and the sixth lies a further 3 km to the west. The other two antennas are the 22-meter Mopra dish near Coonabarabran, close to the Siding Spring optical observatory, and the existing 64-meter dish at Parkes Observatory. When connected by radio links to the Compact Array they form the Australia Telescope Long Baseline Array. The AT can work up to 110 GHz with a bandwidth of 1 GHz. It has a maximum baseline of 300 km.