Australia Telescope National Facility

Interferometers as Fourier filters

The angular resolution of an interferometer (its synthesised beam) is the Fourier transform of the coverage of the 2-element baseline tracks in the uv-plane of the synthesised telescope.

Interferometers with short baselines sample extended structures on the sky, while synthesis telescopes with long baselines sample compact structures. A combination of visibilities from both compact and large configurations will combine sensitivity to extended emission from the short baselines with the resolving power of the long baselines.