HomeMy WebLinkAboutTimes Advocate, 1994-05-11, Page 10Page 10 Times -Advocate, May 11, 1994
c
s PFCIAJ PEA TURE
Usborrie Township's mysterious landmark
The 'Golf' Ball'
Randy Mawson
(left) of the
London Weather
office and Bob
Young look over
the computer
controls and
image
processing
systems housed
in the Exeter
Weather Radar
building. The
resulting
information is
transmitted to
weather
forecasters in
London and all
over the
province.
By Adrian Harte
Times -Advocate Editor
THAMES ROAD - It's one of the most prominent landmarks in the area.
Anyone getting directions out into Usborne Township will often be told to
"take the first concession past the golf ball", or "turn right at the golf ball".
The "golf ball" is the geodesic dome housing the radar dish of the Exeter
Weather Radar. Although it has been part of the skyline of Highway 83
for 20 years, few understand its full purpose. Fewer have been inside.
The station is part of a network of only 22 similar weather radars across
Canada. The nearest stations are in King City north of Toronto, or north
of Parry Sound.
Bob Young, who helps keep the station up and running, says the reason
the radar is located in Osborne Township is because the building beneath
it was originally a radar station for RCAF Centralia at the end of World
War II. Although it was shut down as a communication site in the mid
1950s, and later became a tire re -treading facility, Environment Canada
bought the property with its copper -shielded building to become a weather
radar station in the early 1970s.
Some may recall the old Department of National Defense radar, a top-
secret technology during the war, that used a series of tall towers to track
aircraft. The towers were taken down, and the land sold. Young says
there is a story that the man who bought the land from the government dug
up the heavy copper cables in the fields and sold them for more than the
cost of the property. It's just a story, he says, but given the price of cop-
per, it may just be true.
Today, weather radars use dish antennas. The Exeter station's is 12 -feet
in diameter, and just barely fits inside the fibreglass "golf hall" dome. It
rotates 24 -hours a day, when not being serviced, and continually generates
enmpnteriied images of precipitation patterns up to 200 kilometres away -
everything from Windsor and Detroit to the far side of Lake Huron, up to
Tobermory and past Niagara and Toronto.
As Young explains, it is tuned to a frequency that only picks up water
droplets in the form of rain, snow, or hail. Cloudy weather results in only
a blank screen, unless they're rain clouds.
"Without getting into a lot of witchcraft, it's a very simple radar, and
works well," said Young.
At least that's true today. Until power lines and telephone lines became
more reliable in the 1980s, the radar was nicknamed a "severe weather de-
tector" by London and Toronto weather offices.
"Because as soon as thc weather got had, the radar
would go down," explained Young.
Randy Mawson from the London Weather
Office making his first visit to the station last
week, agrees. He said the station is highly reli-
able these days, and is an invaluable tool in
tracking bad weather coming into the area.
Although the public may be most impressed with
satellite weather images showing clouds scudding
across the continent, Mawson says radar is still the meteor-
ologist's main tool. Satellite photos only show clouds, not
precipitation, and radar can chart the height of cloud forma-
tions. The peak of a thunderhead can be accurately tracked on radar, giv-
ing an exact direction for a serious storm.
"That's important to us, because when it comes to thunderstorms, it
shows us how powerful it is," he explained.
Huron County residents arc familiar with the "snow streamers" that
come off the lake in winter months. Because they are not part of large
weather systems, they have been hard to predict. New computer software
for the radar station can now spot the streamers at low altitudes.
"It's only been the last year or two we've been able to get that," said
Mawson. "This last winter it was invaluable."
Because the colour-coded images of weather moving through the prov-
ince are compiled by the computer every few minutes, they arc of use to
more than just weather forecasters and weather offices. Anyone with a
computer can sign on to make use of the information. The Ministry of
Transportation links up with the radar to prepare snow plow crews, and
even Skydome uses radar to prepare for closing the roof.
The technology today is so accessible that anywhere there is a phone
line, someone can check the weather radar. Young says he often makes
sure it's working with a lap -top computer from the front scat of his car.
Still it's the forecasts that count, and many people are making more use
of them than ever. A farmer Young knows keeps a radio tuned to the
weather -radio frequency of 162.475 khz in his Karn. If the weather's going
to be turning had, he knows it's worth his while to stay up at night to mow
hay.
Even though satellite imagery is seen as more of a space-age technology,
in fact Young says radar is more useful than ever. Although thc same dish
has been sending out its beam from the Exeter station for two decades,
higher -powered computers extract far more information than ever before.
A new computer to be installed this fall will even be able to generate three-
dimensional cross sections of storm clouds, said Young.
As for the future, Environment Canada is working on an experimental
doppler radar, which should actually be capable of tracking air currents.
"There will undoubtedly be a wind profiling radar...so Randy's people
will be able to see a tornado," said Young.
Mawson agreed, saying the ability to predict and warn people of highly
dangerous and destructive weather patterns will likely be well worth the
high cost of such installations.
So while thousands of people drive by the odd looking "golf ball" on
Highway 83, perhaps listening to the weather forecast on the radio, hardly
any will make the connection about where that information came from.
The geodesic dome (right) that sits
mysteriously at the side of Highway 83
just east of Thames Road. Called the
Exeter Weather Radar, it is part of a
nation-wide weather forecasting network.
•
ECHO TOP
1:11
14
12
10
6
am -4
2
Bob Young stands inside the
geodesic golf ball' dome of
the radar station. Beside him
is the motor turret that ro-
tates the aluminum dish in-
side the dome. The back of
the dish can be seen behind
Young.
Below is a radar Image of a
storm system that passed
through the area in Sep-
tember 1992. The original
computer scan separated
cloud height into different col-
oured patterns
HEIGHT EHVJOtI•IEHT Cpi;Ei l 0:1 Tic
F 1'i
H
1
WKR
191a
IS SEP
The Exeter Weather Radar
•The 12 -foot aluminum radar dish rotates every 10 seconds, 7 hours a day.
• It tilts from 24.5 degrees high, down to 0 degrees In a 10 -minute cycle. •-
•Radar is essentially a highly directed beam of radio energy. the dish "listens" for reflections of its beam off water par-
ticles in the atmosphere.
*It operates at 5600 megahertz, 250 kilowatt peak pulse power.
-The radar's useful range Is 200 kilometres.
•Radar range is limited by the curvature of the earth: when the beam Is parallel to the ground at Thames Road, by the
time It passes over Grand Bend it is 1,000 feet high.
•Environment Canada also hes a series of ground stations creating an overlay of temperature and air pressures to corm
plete the weather picture for southem Ontario.
*To build a similar facility today would cost up to $1.5 million.
•A staff of four operates the station, but the main interpretation of the Images is done by the London Weather Office.
•Two farmers' silos near the Exeter station actually cause small blind spots in the radar's coverage at low altitudes.
•Although it uses microwaves, Bob Young says the radar's intensity is so low as to cause no hazard. "The cows grazing
in that field are safe," he said. -