Chapter 2: Global Positioning System
Information Technologies of Tomorrow
The evolution of
information technologies has surpassed expectations for more than a
half-century, and the next
50 years hold even greater promise. As
researchers improve the intelligence capabilities of computers —
particularly the ability to imitate the human process of reasoning — they
will become an integral support in key decision processes. Decisions that
include large numbers of factors involving natural and human processes, such as
those on the military battlefield, will benefit from this capability. Soldiers
will carry wireless devices with sensors that will “read” their
surroundings — physical terrain, air quality, and compass direction —
as well as the soldier's own vital signs. A tiny transmitter will
continuously relay the data back to a command post for analysis by larger
computers as part of an ongoing, real-time decision-making process. As a
result, commanders will have many more options available at an earlier stage,
improving the chances for military success.
Closer to home, we need only consider that there are an
estimated 20 billion microprocessors embedded in products around the world
other than computers: our cars, watches, air conditioners, microwav e ovens,
and VCRs. Soon we will live in “smart houses,” where we will plug
dishwashers, clocks, stereos, and other household appliances into the Internet
along with the electric power grid. At that point, instead of e-mailing home to
ask the family to start dinner, we'll be able to e-mail our kitchen
appliances directly and order them to move the lasagna from the refrigerator to
the oven and cook it at 375° for 45 minutes. The ma rvels of the
Information Age are limited only by the imagination of future engineers and
consumers.
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Mapping Remote Regions
GPS technology has become instrumental in efforts to map
remote regions. The GPS network enables cartographers to create extremely
accurate maps of previously uncharted territory.
G PS has brought enormous benefits to people who live,
work, and play in uncharted terrain. For example, there was no reliable map of
China Camp, a 1,600-acre site in Marin County, CA, which draws more than 2,000
hikers, campers, and mountain bikers every summer. Firefighters sometimes
needed an hour or more to locate a wildfire — and even more time to find a
lost or injured hiker. Now firefighters ride the tr ails of the park on a
mountain bike, using GPS data to follow a highly accurate computerized map of
China Camp that can be used by visitors as well as emergency personnel. These
maps have decreased the department's average emergency response time to
20 minutes.
Across the globe, in sub-Saharan Africa, malaria takes
the lives of more than 1.5 million infants and children under the age of five
each year. In 1995, the U.S. Centers for Disease Control and Prevention (CDC)
initiated a five-year study of the disease, using GPS equipment to map the
location of 450 households, three rivers, major roads (permanent and seasonal),
mosquito breeding sites, medicine stores, local health clinics, a lakeshore,
and other relevant features. By providing more accurate maps of locales —
and even establish ing clear correlations between specific dwellings and
frequency of illness — the project has quickly demonstrated the practical
value of GPS for researching tropical diseases
in remote locations.
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What would it be worth if you could pinpoint your location
anywhere on Earth, whenever you might need to know it, to an accuracy within a
few hundred feet, usin g only an inexpensive handheld device? Would you answer
this question differently if you were an airline pilot concerned that you had
drifted off course? What if you were general manager of a trucking company
trying to save time and money as you schedule the next two days' pickups
and deliveries for a fleet of 200 long-haul trucks? What if you were a weekend
sailor sending a distress radio call because you're in danger?
During the past decade, real people like those described —
and thousands of others in a wide range of scenarios — have relied
increasingly on the Global Positioning System (GPS) to calculate precise
location. This ability, undreamed of before the age of satellites, has already
saved countless lives and dollars for those who use it.
GPS consists of a
constellation of 24 satellites that orbit the Earth every 12 hours, each emitt
ing radio signals coded with data about its position and the time —
accurate to within a billionth of a second. The satellites are deployed so that
every point on Earth can always receive signals from at least four satellites.
Receivers on Earth interpret these signals to pinpoint their own positions,
anywhere on the globe, at any time of day or night, in any kind of
weather.
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Saving Lives
Mitch Buffim of Buffalo, New York, knows firsthand what
GPS can do. Buffim is one of 500 volunteers in Erie County who are testing a
new GPS-based automatic collision notification (ACN) system . After working a
late shift one night last April, Buffim fell asleep at the wheel while driving
home on a rural road. His car ran off the road, rolled on its side, and slid
down a steep embankment. With no witnesses and his car invisible
from the
roadway, he could have waited hours for help. However, almost before the car
stopped moving, Buffim heard the emergency dispatcher's voice in t he car.
“This is Erie County Dispatch. We have your location. Are there any
injuries? How many occupants are in your car?” Thanks to the ACN system in
Buffim's vehicle, the dispatcher knew the exact location of the vehicle,
its speed, and the force of the impact. Help was on the way almost instantly.
Single-vehicle rural crashes like Buffim's account for one-third of all
fatal crashes nationwi de. ACN is connecting these crash victims with emergency
care well within the “golden hour” that often means the difference
between life and death. If help can arrive ten minutes sooner during this first
hour, 9,000 lives may be saved across the nation each year. |
A Breakthrough Based on Basic Research
The GPS we use
today would not have been possible wit hout basic scientific research in atomic
and molecular physics or advances in satellite, launch vehicle, and
telecommunications technology. GPS technology actually grew out of pure physics
research, starting in the 1930s, by scientists studying the nature of the
universe and how to measure time exactly. By the 1950s, this research had
developed extremely accurate atomic clocks, which would later be crucial in
developing the concept of GPS. The adve nt of space satellites, with the Soviet
Union's launch of Sputnik I in 1957, allowed scientists and engineers to
envision a system of navigation that would rely on satellite signals keyed to
precise timekeeping. By 1973, the Department of Defense had approved the
navigational concept that became GPS. Rockwell International began building the
Navstar satellites that make up the GPS constellaion, each the size of a large
automobile and weighing slightly less than a ton. In 1978, the first GPS
satellite became operational; by 1993, the full 24-satellite system was in use.
Technological advances in solid state electronics, microchips, and microwaves
also contributed to the commercial success of GPS. In 1983, the first GPS
receivers cost over $150,000 and weighed more than 100 pounds. Today, a
handheld GPS receiver weighing less than a pound can be purchased for less than
$100.
Most Americans first became aware of GPS when the U.S. military
used it successfully in the 1991 Gulf War to target “smart” bombs and
cruise missiles. In the deserts of Kuwait and Iraq, GPS gave U.S. forces a
precise and reliable sense of where they were in unfamiliar territory. GPS
again made headlines in 1999, when a U.S. F-16 went down in the northwestern
part of Serbia during Operation Allied Force in the liberation of Kosovo. The
Ame rican pilot was rescued by NATO forces and taken to safety within a matter
of two hours, thanks to GPS technology.
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Improving Transportation Efficiency
Public and private organizations rely on GPS and other
technologies to improve transportation safety and efficiency. The cascade of
benefits includes millions of dollars in savings thr oughout the economy,
enhanced customer satisfaction, and improved air quality. For example, each of
Denver's 800 buses is equipped with a GPS-based automatic vehicle location
system that reports the location of the bus every two minutes. Dispatchers have
improved their ability to keep buses running on time by viewing bus locations
on computer screens that are fully integrated with digital city maps. The syst
em is credited with increasing use of the bus system, relieving traffic
congestion, and reducing smog.
GPS tracking technology at the American President
Line's Global Gateway South at the Port of Los Angeles automatically
matches a cargo container's identification number with its location in the
yard. Back at the terminal, a computer stores the GPS location and con tent
data for each container. Using on-board navigation, drivers can now negotiate
the 6,000-space holding tank and drive straight to the proper container the
first time, eliminating costly mistakes and saving time and money. The system
increases the overall efficiency of the cargo storage space, an important
benefit for port facilities with no room for expansion. |
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