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NEXRAD (Next Generation Radar) is the next generation of weather
radar technology that is operational at 158 sites throughout the
United States and at selected overseas locations.
Meteorologists can now warn the public to take shelter with more
notice than any previous radar. The maximum range of the NEXRAD
radar is 250 nautical miles. The NEXRAD network provides
significant improvements in severe weather and flash flood
warnings, air traffic safety, flow control for air traffic,
resource protection at military bases, and management of water,
agriculture, forest, and snow removal.
The NEXRAD is capable of operating in three different modes,
Precipitation mode, Clean air Mode, and Severe weather mode. The
radar is placed in precipitation mode when a significant amount
of precipitation is detected. It completes nine full scans at
different elevation angles between 0.5 and 19.5 degrees and is
updated every six minutes. The NEXRAD offers much more
resolution in precip levels. Old radars only had six precip
levels, the NEXRAD has fifteen levels, which enables it to give
more accurate descriptions on the intensity of precipitation.
When the NEXRAD is placed in clean air mode the radar becomes
more sensitive and is updated every ten minutes after completing
five full scans at different elevation angles between 0.5 and
4.5 degrees. It is useful to measure those winds in "clear air"
from very weak returns on dust, insect, smoke, etc. It is also
capable of depicting snow very well, a feature that old radars
had trouble with. The Severe weather mode is activated when a
severe weather pattern is detected. The radar then completes
fourteen scans between 0.5 and 19.5 degrees in five minutes. The
NEXRAD calculates both the speed and direction of motion of
severe storms. By providing information on wind patterns within
developing storms, the NEXRAD identifies conditions leading to
tornadoes and can subsequently give accurate data on the
direction and speed of formed tornadoes.
Additional information available at
"http://www.roc.noaa.gov/"
[Summary provided by NOAA Radar Operations Center]
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| Abstract from DBPedia | NEXRAD or Nexrad (Next-Generation Radar) is a network of 160 high-resolution S-band Doppler weather radars operated by the National Weather Service (NWS), an agency of the National Oceanic and Atmospheric Administration (NOAA) within the United States Department of Commerce, the Federal Aviation Administration (FAA) within the Department of Transportation, and the U.S. Air Force within the Department of Defense. Its technical name is WSR-88D (Weather Surveillance Radar, 1988, Doppler). NEXRAD detects precipitation and atmospheric movement or wind. It returns data which when processed can be displayed in a mosaic map which shows patterns of precipitation and its movement. The radar system operates in two basic modes, selectable by the operator – a slow-scanning clear-air mode for analyzing air movements when there is little or no activity in the area, and a precipitation mode, with a faster scan for tracking active weather. NEXRAD has an increased emphasis on automation, including the use of algorithms and automated volume scans.NEXRAD (NEXt-Generation RADar) は、アメリカ合衆国商務省の海洋大気庁内の国立気象局が運用する、159地点に設置されたドップラー式の高解像度気象レーダー網である。技術的な正式名称は"WSR-88D"で、Weather Surveillance Radar, 1988, Doppler（「1988年のドップラー式気象監視レーダー」）という意味が込められている。 (Source: http://dbpedia.org/resource/NEXRAD) |
