Australia Telescope Compact Array

The Australia Telescope Compact Array ( ATCA ) is a radio interferometer for astronomical observations with site near Narrabri, Australia.

ATCA consists of six radio telescopes with 22 m diameter antenna that can be positioned at various stations with up to 6 km in east-west direction. Its location, the Paul Wild Observatory, located about 30 km west of Narrabri and about 500 km north- west of Sydney in 234 m height. ATCA has receiver for radio wave lengths of between 20 cm and 3 mm. Together with the large radio telescope at Parkes Observatory and another radio telescope in MoPra ATCA is also used for Very Long Baseline Interferometry.

ATCA is currently the most powerful radio interferometer in the southern hemisphere. Together with other Australian radio telescopes is part of the ATCA Australia Telescope National Facility ( ATNF ) and is administered by the Australian research organization CSIRO.