Todays
air traffic control systems are based partly on design principles
developed by NIST, which in the early 20th century developed several
radio technologies that made sea and air navigation much safer.
These included the first visual type radio beacon for
an instrument landing system, which enables an air crew to locate
and land on a runway in poor visibility.
Weather forecasting
was vastly improved in 1936 when NIST built a radiosonde, a
balloon-borne instrument that increased the range and quantity of
available weather data by transmitting information on cloud height
and thickness, temperature, pressure, and other phenomena. Radiosondes
still are used today.
NIST played
a major role in a leading technical advance of the World War II
era when it assisted in the design of early smart weapons
systems used by the Allies. The most important of these weapons
was the radio proximity fuse, which exploded a projectile when directly
over its target, rather than on impact, making the weapon five to
20 times more effective.
The Global Positioning
System and other communications and navigation technologies are
more accurate thanks to improved timekeeping, a trend promoted
by NISTs operation of the first atomic clock, which was based
on the ammonia molecule, in 1949. Atomic clocks are based on the
resonances, or vibrations, of atoms or molecules. NISTs latest
atomic clock neither gains nor loses a second in nearly 20 million
years.
Cryogenic refrigerators
and the worlds largest hydrogen liquefier are among the novel
technologies resulting from NIST research on cryogenics, a branch
of physics dealing with the production and effects of very low temperatures.
Over the 20th century, this research has contributed to scientific,
military, aerospace, industrial, and medical fields.
The first
operational, internally programmed digital computer in the United
States was built by NIST. Dedicated in 1950, the Standards Eastern
Automatic Computer incorporated a number of engineering innovations,
including a graphical display that produced the first computerized
image in 1957. To input that image, NIST researchers built the first
scanner.
Products ranging
from compact disk players to missile guidance systems are made worldwide
with voltmeters that are calibrated using standards based on technology
developed by NIST in the 1980s. The new standard for the volt,
which made use of a single, simple equation of physics, was more
accurate, more stable, and much easier to use than its predecessors.
Date created:
2/9/01
Last updated: 2/9/01
Contact: inquiries@nist.gov
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