SETI stands for "Search for Extraterrestrial Intelligence".
The SETI public announcement of the start of the Allen Telescope Array is found at the website “Allen Telescope Array Begins Scientific Observations.”
The ATA is being funded with U.S.$25 million through American philanthropist Paul G. Allen, the co-founder of Microsoft Corporation. The Array started in 2001 with an $11.5 million donation from the Paul G. Allen Family Foundation. After three years, the Foundation agreed to donate another $13.5 million after the research and development phase showed promising success.
The ATA is a centimeter-wavelength radio interferometer that is exclusively to be used for astronomical observations (by the RAL) and the search for extraterrestrial intelligence (by SETI) within the Milky Way galaxy—simultaneously, by splitting the signal before final processing.
In astronomy, an interferometer combines the signals from two or more telescopes (with the use of computers) to obtain measurements that are better quality than would be possible with its individual telescopes being used separately.
The RAL (University of California—Berkeley) group has control over what will be viewed. The Array was previously called the One Hectare Telescope.
Its purposes are to measure the density of the early universe, analyze stellar formation, research magnetic fields in the interstellar medium, and other astronomical endeavors.
According to Space.com, Allen is quoted to have said, “I am very excited to be supporting one of the worlds most visionary efforts to seek basic answers to some of the fundamental question about our universe and what other civilizations may exist elsewhere. I am a big proponent of leveraging revolutionary technology and design and applying it to important problems in science. The developments taking place with this new instrument will not only enables us to realize a lot of bang for our research and development buck, but it will also change the landscape of how telescopes will be built in the future. An instrument of this magnitude, which will result in the expansion of our understanding of how the universe was formed, and how it has evolved, and our place therein, is the reason I am the primary supporter of its development, design and construction."
The ATA, currently, consists of 42 radio antennas (first phase: ATA-42) that are each 20 feet (6 meter) in diameter. All of the antennas were manufactured in mass from one mold. They also use inexpensive telecommunications technology. All are linked with a computer so that all of the antennas can be used as one giant dish--as an interferometer.
It is located at the Hat Creek Radio Observatory, which is about 300 miles (480 kilometers) northeast of San Francisco, California, U.S.A. The completion of 206 antennas, ATA-206, is scheduled next. When it is ultimately completed, tentatively scheduled for late in the 2010s and at a cost of about 41 million more dollars, it will consist of 350 antennas (ATA-350).
When finished, it is expected to be one of the world’s fastest and most powerful telescopes. In its first operation, the ARA produced images of the Andromeda Galaxy.
According to SETI Institute astronomer Seth Shostak, “For SETI, the ATA’s technical capabilities exponentially increase our ability to search for intelligent signals, and may lead to the discovery of thinking beings elsewhere in the universe. It is the first major telescope in the world built specifically for undertaking a search for extraterrestrial intelligence.”
The University of California, Berkeley website for the Allen Telescope Array is: http://ral.berkeley.edu/ata/.
The SETI Institute website for the ATA is: http://www.seti.org/seti/projects/ata/.