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Across the United States,
various groups use Doppler radar to gather information
vital to our everyday lives.
From weather forecasting,
to military operations,
to emergency management,
the Next Generation Weather Radar, or NEXRAD,
ensures public safety and enhances commerce.
A world-wide network of 167 NEXRAD radars
provides weather coverage for the entire United States
and select international locations.
The formal name of the radar is the WSR-88D
which stands for
for the year the design was established
The radar network is supported by the
Radar Operations Center in Norman, Oklahoma.
Their job is to keep the radars running smoothly
and improve radar technology and capabilities.
To maintain peak performance for all radars,
the Radar Operations Center help desk
offers 24 hour expert assistance to radar technicians
around the world.
Hardware and software upgrades
apply new science and increase radar productivity.
The support provided by the Radar Operations Center
allows the radar network to deliver
continuous, reliable weather coverage to its users.
The radar collects data by sending
a radio signal out to a target.
The signal bounces off the target
- raindrops, in this case -
and returns to the radar.
The returned signal conveys
three important properties of the target.
First: The time it takes for the signal to bounce off
the target and return determines the distance
from the target area to the radar
and thus the location of the storm.
Second: the strength of the returned signal,
also known as reflectivity,
is proportional to the size and number
of raindrops in the storm.
Third: The frequency of the returned signal
reveals whether the winds are moving
toward or away from the radar,
as well as their speeds.
The combination of speed and direction
is called the velocity.
The data is converted into visual images
and used by National Weather Service forecasters,
the Federal Aviation Administration,
and the military to provide weather support
to the nation.
In addition, selected visual images
are made available on the web
and shown on TV weather broadcasts.
Radar data is also used by private companies
and studied by university researchers
to improve forecasts.
Forecasters use the continuous,
immediate weather information provided by radar
to track storms and warn the public of dangerous weather.
Radar allows forecasters to see all types of weather
and provide advanced warning for
thunderstorms,
hail,
tornadoes,
hurricanes,
wildfires,
flash floods,
snow,
and freezing precipitation.
A recent study proved Doppler radar
helped reduce tornado deaths and injuries
by nearly half - nationwide.
By using Doppler radar
forecasters have increased the average tornado
warning lead time to nearly thirteen minutes.
Outside of the National Weather Service,
other groups use Doppler radar to collect information
about the weather and the atmosphere.
The Federal Aviation Administration
benefits from NEXRAD by overlaying
weather radar data on air traffic control displays.
This capability helps traffic flow managers
safely route air traffic
and reduce weather delays for travelers.
The Department of Defense uses radar data
to help plan missions for land, sea, and air operations.
With accurate weather information,
the military is able to enhance flight safety,
maximize training opportunities,
and protect military assets and personnel.
Community leaders use radar to protect
their citizens from nature's destructive forces.
Local emergency managers monitor storms on radar
and determine their exact locations.
"Moore 911, where's your emergency?"
This is used to notify their communities
of approaching danger
and better coordinate emergency response.
Early winter weather forecasts give snow removal
crews lead time to plan and react more effectively.
Water management agencies use radar to estimate
not only how much rain will fall,
but where it will fall.
Radar is especially useful for collecting rainfall data
where there are spatial gaps between rain gauges.
Improved precipitation estimates help water
managers monitor and control the water supply.
Homeland security managers can now integrate
wind measurements with computer models
to determine the exact path of chemical
and biological agents released accidentally
or as a result of a terrorist attack.
Radar can also detect the density, location,
and direction of biological targets like birds,
insects, bats and butterflies.
For instance, ornithologists use the data
to study the flight and migration patterns of birds.
Private meteorological companies can provide
tailored products to their customers
by adding specialized features and information
to NEXRAD data.
Local and national television meteorologists
use NEXRAD data to keep their viewers informed
of real-time weather conditions.
Even if a station has its own weather radar,
they will often use regional NEXRAD data
to provide a broader view of the weather
approaching their area.
Today's weather radar technology and capabilities
are a direct result of decades
of research and development.
What began as a strategic weapon in World War II
has evolved into a world-class
weather detection system.
Continuous improvements to the radar's
hardware and software have been made since 1988.
Recently, new equipment upgrades will allow
better detail in the images forecasters see.
The next step is dual polarization,
an additional capability that allows NEXRAD radar
to send and receive both horizontal
and vertical pulses.
This new information will give meteorologists
a better idea of the structure and type
of precipitation - resulting in more accurate forecasts.
The research done today will continue
to give us benefits for years to come.
With its eye to the sky,
the NEXRAD radar provides critical information
used by a variety of people
for many different purposes.
It is not only a vital tool for forecasting
and researching weather
but for many everyday activities
that impact us all.