راهنمای جامع سنسورها
Integrated sensors and control systems are the way of the future. In times of disaster, even
the most isolated outposts can be linked directly into the public telephone network by portable versions of satellite earth stations called very small aperture terminals (VSATs). They
play a vital role in relief efforts such as those for the eruption of Mount Pinatubo in the
Philippines, the massive oil spill in Valdez, Alaska, the 90,000-acre fire in the Idaho forest,
and Hurricane Andrew’s destruction in south Florida and the coast of Louisiana.
LIDAR (light detection and ranging) is an optical remote sensing technology that
measures properties of scattered light to find range and/or other information of a distant
target. The prevalent method to determine distance to an object or surface is to use laser
pulses. Like the similar radar technology, which uses radio waves instead of light, the range
to an object is determined by measuring the time delay between transmission of a pulse and
detection of the reflected signal. LIDAR technology has application in archaeology, geography, geology, geomorphology, seismology, remote sensing, and atmospheric physics.
VSATs are unique types of sensors and control systems. They can be shipped and
assembled quickly and facilitate communications by using more powerful antennas that are
much smaller than conventional satellite dishes. These types of sensors and control systems
provide excellent alternatives to complicated conventional communication systems, which
in disasters often experience serious degradation because of damage or overload.
Multispectral sensors and control systems will play an expanding role to help offset the
increasing congestion on America’s roads by creating “smart” highways. At a moment’s
notice, they can gather data to help police, tow trucks, and ambulances respond to emergency crises. Understanding flow patterns and traffic composition would also help traffic
engineers plan future traffic control strategies. The result of less congestion will be billions
of vehicle hours saved each year.
In Fig. I.1, the Magellan spacecraft is close to completing its third cycle of mapping the
surface of planet Venus. The key to gathering data is the development of a synthetic aperture
radar as a sensor and information-gathering control system, the sole scientific instrument
aboard Magellan. Even before the first cycle ended, in mid-1991, Magellan had mapped
84 percent of Venus’ surface, returning more digital data than all previous U.S. planetary
missions combined, with resolutions ten times better than those provided by earlier missions. To optimize radar performance, a unique and simple computer software program
was developed, capable of handling nearly 950 commands per cycle. Each cycle takes a
Venusian day, the equivalent of 243 Earth days.
Manufacturing organizations in the United States are under intense competitive pressure. Major changes are being experienced with respect to resources, markets, manufacturing processes, and product strategies. As a result of international competition, only the most
productive and cost-effective industries will survive.
Today’s sensors, remote sensors, and control systems have explosively expanded
beyond their traditional production base into far-ranging commercial ventures. They will
play an important role in the survival of innovative industries. Their role in information