Mobile phones may foil stealth bombersBy Robert Uhlig in London America's multi-billion-dollar stealth bombers
could be rendered obsolete by a British invention that uses existing mobile
telephone masts to detect and track aircraft that were previously invisible
to radar.
US stealth fighters and bombers such as the F117, B1 and B2 played key
roles
in the Gulf and Kosovan wars as they are almost impossible to detect using
conventional radar.
However, the ease with which the mobile telephone mast system - developed
at
a laboratory in Hampshire - can be used to detect the aircraft has greatly
concerned the military.
Mr Peter Lloyd, the head of projects at Roke Manor Research, said: "I
cannot
comment in detail because it is a classified matter, but let's say the US
military is very interested."
Stealth aircraft, each of which costs at least $A3.6 billion, are shaped to
confuse radar. A special paint absorbs radio waves, reducing the radar
signature to the equivalent of a gull in flight.
The Roke Manor scientists discovered that telephone calls sent between
mobile
phone masts detected the precise position of stealth aircraft with ease.
"We
use just the normal phone calls that are flying about in the ether," Mr
Lloyd
said. "The front of the stealth plane cannot be detected by conventional
radar, but its bottom surface reflects very well."
Mobile telephone calls bouncing between base stations produce a screen of
radiation. When the aircraft fly through this screen they disrupt the phase
pattern of the signals. The Roke Manor system uses receivers, shaped like
television aerials, to detect distortions in the signals.
A network of aerials large enough to cover a battlefield can be packed in a
Land Rover.
Using a laptop connected to the receiver network, soldiers on the ground
can
calculate the position of stealth aircraft with an accuracy of 10 metres
with
the aid of the GPS satellite navigation system.
"It's remarkable that a stealth system that cost £60 billion [$158 billion]
to develop is beaten by £100,000 mobile phone technology," Mr Lloyd said.
"It's almost impossible to disable a mobile phone network without bombing
an
entire country, whereas radar installations are often knocked out of action
with a single bomb or missile."
The Telegraph, London
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