The Very Long Baseline Array or VLBA is a collection of ten identical 25 metre antennae distributed mainly across continental USA, but with dishes in Hawaii and the Virgin Islands. The VLBA is essentially a dedicated Very Long Baseline Interferometer.

The array operates between frequencies of 300 MHz and 86 GHz, and is operated by National Radio Astronomy Observatory (NRAO). Like most VLBI arrays it observes sources at very high spatial resolution and is thus best suited for observations of radio sources at the smallest scales such as distant quasars and extragalactic radio jets.

Montage of the VLBA, its antenna locations, and the antennae themselves.
Credit: Image courtesy of NRAO/AUI and Earth image courtesy of the SeaWiFS Project NASA/GSFC and ORBIMAGE