cell base stations find stealth planes

[Alfred Qaeda]

Mobile phones may foil stealth bombers

                By 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."
http://www.smh.com.au/news/0106/12/world/world2.html