ATCA

The Australia Telescope Compact Array (ATCA) is a radio interferometer operated by CSIRO Astronomy and Space Science as part of the Australia Telescope National Facility. Located at the Paul Wild Observatory near Narrabri in New South Wales, Australia, the array consists of six 22-meter antennas.

The antennas can be moved along a fixed rail track to form different configurations, yielding baselines up to about 6 kilometers. This arrangement enables interferometric measurements that synthesize a large aperture and deliver high angular resolution at centimeter wavelengths.

ATCA supports multiple receiver bands across centimeter wavelengths and uses a dedicated correlator and backends to process the signals. In 2009–2010, the facility received the Compact Array Broadband Backend upgrade, significantly widening instantaneous bandwidth and sensitivity.

Since commissioning in the late 1980s, ATCA has been used to study a wide range of astronomical objects, including galaxies, active galactic nuclei, pulsars, supernova remnants, and star-forming regions. It also participates in global very long baseline interferometry networks for higher resolution.

The facility is part of CSIRO's broader research infrastructure and remains a foundational instrument for Australian radio astronomy.