[Scan-DC] The Quiet Zone

[b_thom@juno.com]

http://www.dcski.com/news/2004/02_09_2004/briefs.php3

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Travelers passing through the town of Green Bank on the way to West
Virginia's Snowshoe Mountain Resort are often startled to see an
enormous, otherworldly metallic structure rising above the ground. The
structure looks distinctly out of place among the farms and valleys of
the area, but serves a valuable purpose: listening to radio signals from
outer space. Astronmers can answer questions about the Universe by
studying the signals emitted by distant galaxies.

The large radio telescope is one of several located at the National Radio
Astronomy Observatory (NRAO) in Green Bank. These telescopes can focus in
on signals that are weaker than 0.00000000000000000000000001 watts --
incomprehensibly weaker than the signal emitted from your cell phone or a
walkie talkie. The NRAO was located in the valley of Green Bank due to
the natural shielding from electronic interference provided by the
surrounding mountains. Visitors to NRAO must ride in diesel-powered
trucks built in 1969 and 1970; newer vehicles, with all of their
electronic gadgetry, would cause too much interference to the sensitive
telescopes. But, as an article in the February issue of Wired Magazine
points out, the growing ubiquity of wireless devices -- from cell phones
to pagers to WiFi laptops -- is beginning to cause problems for the
scientists at Green Bank.

Snowshoe Mountain Resort is located just over the hill from Green Bank,
and Wired describes the unique challenges Snowshoe faces to minimize the
possibility of interference with the nearby radio telescopes. Most large
ski resorts place radio repeaters across the mountain, allowing ski
patrol and mountain operations personnel to stay in touch with each
other. But these repeaters would cause large headaches to the researchers
at the NRAO, so Snowshoe installed a more expensive hardwired
communications systems.

Snowshoe faced a more recent challenge when it constructed the Sunrise
Backcountry Hut, profiled here last season on DCSki. Accessible by
snowshoe or snowmobile, the Hut allows visitors to enjoy a homecooked
meal, or to stay overnight in one of the resort's more adventurous
lodging options. The Backcountry Hut offers a great view of Green Bank
below -- it's located just 7.5 miles from the NRAO's primary telescope,
with no mountains in the way.

Wired magazine reports that Snowshoe wanted to install a radio
transmitter in the Hut, so a fire alarm could instantly be relayed to
Snowshoe's fire response personnel. But a conventional transmitter would
wreak havoc on the telescope. To solve the problem, Snowshoe worked with
NRAO personnel to develop a highly directional antenna that would beam
its signal at a 90-degree angle away from the telescope and towards a
Verizon wireless base station 40 miles south, using just 3 watts of power
versus a traditional 48. The Verizon base station then redirects the
signal back to Snowshoe in a split second.

Although the directional antenna solved the problem, visitors to Snowshoe
can unknowingly interfere with the NRAO's operations. A skier whipping
out a Motorola Talk About 2-way radio on Widowmaker can potentially
disrupt the work of scientists at the Observatory.

Submitted by M. Scott Smith.
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