Decaying antenna farm hints at glorious radioastronomy past (Forwarded)

News Service
Stanford University
Stanford, California

Contact:
Dawn Levy, News Service
(650) 725-1944,

Comment:
Ronald Bracewell, Electrical Engineering
(650) 723-3545,

October 12, 2004

Decaying antenna farm hints at glorious radioastronomy past
By Dawn Levy

The Dish is Stanford's most famous antenna. But on the other side of Highway
280, down a dirt road and over a wooden bridge, five smaller dishes languish in
obscurity, the remnants of radioastronomy experiments terminated in the '70s.
Nonetheless, they've managed to attract some attention -- that of the
university's fire inspector, David Conrod. In June, his visit to the site, which
was on a watch list, revealed weed-choked meadows, dilapidated sheds and rusting
equipment. He declared the area, known simply as Site 515, a fire hazard and
called for its cleanup.

"It looks like a Mayan ruin," Professor Channing Robertson, senior associate
dean for faculty and academic affairs in the School of Engineering, said. The
cost of demolition and cleanup is estimated at $100,000. The university, the
School of Engineering and the Electrical Engineering Department will share the
expense of reducing vegetation to a level compliant with state fire code -- a
task expected to be complete by rainy season -- and of cleaning up scrap metals
on the site and demolishing most buildings there.

Robertson called a temporary halt to the demolition last summer once it became
apparent that Site 515 was significant for its roles in experiments conducted by
electrical engineer Ronald N. Bracewell and other scientists of Stanford's
Space, Telecommunications and Radioscience Laboratory (STAR Lab). Demolition of
the site's five remaining dish antennas and the building housing the
radiotelescope control room has been delayed until June 30, 2005, to give any
interested parties a chance to submit proposals for site use.

Ultimately, the university will decide the site's fate. Possibilities include
reassignment of the land for a new use by the provost or continued use for
university research projects. For example, Electrical Engineering Professor
Umran Inan, who leads STAR Lab, is interested in using one or more of the dishes
to track scientific satellites carrying Stanford-built instruments.

Robertson has asked electrical engineering faculty, many of whom toured the site
Aug. 17, to propose ways to commemorate the research done there. Bracewell has
several photo albums documenting the site's construction and experimental
apparatuses. He and others are interested in saving some of the concrete
pediments on which the small antenna dishes were mounted. In the '60s and '70s,
proving that even scientists are not above graffiti creation, more than 200
astronomers -- many famous -- chiseled their John Hancocks into the concrete.

Stellar past

So what was Site 515 used for in the first place?

"This location [is] where antennas first reached the angular resolution of the
human eye and the microwave sun was mapped for 11 years at daily intervals with
an innovative scanning technique with the first radiotelescope ever to print its
output (the temperature map) in published form," Bracewell, the Lewis M. Terman
Professor, Emeritus, wrote in an e-mail interview.

Bracewell came to Stanford in 1955. In 1956, he began to design and build an
array of 32 small dish antennas, each 10 feet in diameter, arranged as a cross.
The dishes of each arm of the cross were slaved together to move in unison. A
similar antenna placed a distance from the cross improved the array's
resolution. Beginning in 1961, this "antenna farm" mapped microwaves emitted by
the sun. Seven days a week for the 11 years that it took to complete a solar
cycle, STAR Lab staff member Joel Deuter would send a microwave
spectroheliograph, a temperature map of the sun, to Colorado Springs for the Air
Force to distribute around the world. NASA used the solar weather maps, which
could predict radiation peaks, to support the first manned landing on the moon.

Subsequently, an array of five larger antennas -- each 60 feet in diameter --
was built. Today their rusty remains are sandwiched between giant mounds of
horse manure and a tree farm, on land dominated by jackrabbits, gopher snakes
and poison oak. The big dishes were not used in sun-mapping experiments.
Instead, they reached out farther into space to study angular diameters,
temperatures and polarization of complete galaxies -- characteristics that
revealed the direction of motion of our solar system relative to the cosmic
background.

The celestial research conducted at Site 515 also resulted in earthly benefits.
The algorithm that Bracewell created to reconstruct astronomical images from
scans was universally adopted in computer-assisted tomography (CAT) scanners for
medical diagnosis. For that accomplishment, the native Australian was elected a
foreign associate of the National Academy of Sciences' Institute of Medicine and
received the Heinrich Hertz Medal from the Institute of Electrical and
Electronics Engineers.

Relevant Web URLs:

* STAR LAB
http://nova.stanford.edu/

Editor Note:

Photos of the antennas are available at
http://newsphotos.stanford.edu/Antenna_2004.jpg (674KB)