MILLIONS of navigation devices around the wor=
ld face the threat of failure at midnight next Saturday when a global sat=
ellite network is hit by its own version of the Millennium bug. Experts are worried about the risk of accidents to light pl=
anes and sailing boats.
Fear of the "end-of-week" bug has prompted government agencies in America=
to alert pilots, sailors, as well as drivers, climbers, hikers and other=
s who rely on the Global Positioning Satellite system. Warnings have also=
been issued by the International Maritime Organisation and Ireland's min=
ister of marine and natural resources.
=
But in Britain, where such devices are common and where the Ministry of =
Agriculture, Fisheries and Food will require all fishing vessels over 24 =
metres long to carry GPS monitoring terminals from 2000, no official warn=
ings have been issued. This is despite the fact that the bug could disabl=
e systems and endanger life as planes and boats approach air and seaports=
=2E
A spokesman at the Department of the Environment, Transport and the Regi=
ons said: "It is an American system and people chose to buy into it, so i=
t is their look-out." He said that the ministry had known about the probl=
em for some time and was relying on "information filtering down to the ow=
ners of private aircraft" and other amateur users from aeronautical infor=
mation circulars.
He said: "There is the risk that for a short period equipment could be g=
iving out wrong signals, but I understand that the equipment does right i=
tself." He added that the department had "no obligation" to warn users. T=
he US Defence Department, which runs the GPS network, or the Federal Avia=
tion Authority was responsible.
The bug has arisen because the GPS system, a constellation of 24 satelli=
tes around the globe, keeps track of time by counting the number of weeks=
since it went into operation in 1980. The counter, which allows for abou=
t 20 years' worth of weeks, computes up to 1,023. At midnight next Saturd=
ay, week 1,023 ends and the counter rolls back to zero.
An American congressional sub-committee heard in May that, while militar=
y, space and most commercial systems were well prepared, small businesses=
and amateur users could be hard hit. Keith Rhodes, technical director in=
the Office of the Chief Scientist, told the sub-committee: "The satellit=
es will not fall out of the sky and will not lose their power. The proble=
m will be on the ground, with what you hold in your hand."
Hand-held receivers such as those popular with mountaineers, sailors and=
some motorists were "probably going to have a problem" if they were more=
than five years old.
A notice issued by the United States transport department said: "Consumer=
s who depend on GPS at sea, on land or in the air may experience one of t=
hese problems with their receiver: it will be unable to locate the satell=
ites, resulting in the receiver not working; it will take more time than =
usual to locate the satellites; it will appear to be working but display =
inaccurate positions, times or dates."
David Rowlands, a senior official at the British transport department, t=
old a Commons select committee last November that receivers affected by t=
he bug "would not generate false readings but would simply fail".
The Ministry of Defence said that it had completed all the necessary fix=
es to its equipment. A spokesman said: "We will not have any problems. GP=
S is used extensively, but as a complementary system. We have updated all=
systems as necessary, including cruise missiles on submarines."
Civilian GPS receivers have been available for about 10 years and are ro=
utinely built into cars, sailing boats, light aircraft and even London ta=
xis. They cost as little as £100 and are now being incorporated in =
watches and mobile telephones.
Each of the 24 satellites in the system carries an atomic clock from whi=
ch it transmits a continuous time signal. By comparing the time signals f=
rom at least three satellites, a receiver can use triangulation to work o=
ut its position on Earth to an accuracy of 30ft. As with the Millennium b=
ug, nobody knows exactly how far-reaching the consequences of the atomic =
clocks resetting themselves to week zero will be to the navigation device=
s.
John Lovell, director of quality for Trimble Navigation Ltd, the leading=
maker of GPS devices, said that products bought in the past three to fiv=
e years would not have any serious problems. He said: "There is a very sm=
all chance of a navigational error, but not zero. Everyone should check w=
ith the manufacturer to make sure."
Garmin and Magellan, two other leading makers of GPS equipment, have pos=
ted information for their customers on their web sites. Garmin issued a w=
arning that some of its older products might need "to perform an 'autoloc=
ate' or 'search the sky' operation to acquire satellites and perform navi=
gation functions after the GPS week number rollover occurs".
The company said also that its equipment could malfunction when used in =
conjunction with other incompatible equipment, data or software, such as =
electronic charts or auto-pilot systems. Magellan, which has sold more th=
an a million receivers since 1989, has been testing all its current and d=
iscontinued receivers, starting with the most recently released products.=
It described the task of testing more than 100 products as "an enormous =
and an important one". With less than a week to go, only 51 of its produ=
cts are listed on its web site as "end-of-week compliant". People with pr=
oducts not judged to be compliant are advised to contact Magellan, which =
will determine whether the product should be fixed or modified.
Nigel Waterson, the Tories' transport spokesman, condemned the Governmen=
t for not taking a more active role in warning the public. He said: "It i=
s potentially a very irresponsible attitude. We may be talking about the =
safety of yachtsmen and other British users. Whatever the origins of the =
satellite system, it is not something that ministers can wash their hands=
of."
=
1 July 1999: [Connected] Travellers' delight at OS-GPS marriage
=
14 January 1999: [Connected] All at sea? Combination displays could help<=
/a>
23 July 1998: [Connected] When all else fails, you can trust a star<=
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