Very Large Array
Very Large Array — The Very Large Array, one of the world’s premier astronomical radio observatories, consists of 27 radio antennas in a Y-shaped configuration on the Plains of San Agustin fifty miles west of Socorro, New Mexico.
Each antenna is 25 meters (82 feet) in diameter. The data from the antennas is combined electronically to give the resolution of an antenna 36km (22 miles) across, with the sensitivity of a dish 130 meters (422 feet) in diameter.
The VLA is an interferometer; this means that it operates by multiplying the data from each pair of telescopes together to form interference patterns.
The structure of those interference patterns, and how they change with time as the earth rotates, reflect the structure of radio sources on the sky: we can take these patterns and use a mathematical technique called the Fourier transform to make maps.
The VLA is used primarily by astronomers from around the world. It’s also occasionally used for atmospheric/weather studies, satellite tracking, and other miscellaneous science.
The total cost was $78,578,000 (in 1972 dollars), roughly $1 per taxpayer at the time; the project was completed nearly one year early, and within the allotted budget.