Search results
Results From The WOW.Com Content Network
Weather radar in Norman, Oklahoma with rainshaft Weather (WF44) radar dish University of Oklahoma OU-PRIME C-band, polarimetric, weather radar during construction. Weather radar, also called weather surveillance radar (WSR) and Doppler weather radar, is a type of radar used to locate precipitation, calculate its motion, and estimate its type (rain, snow, hail etc.).
The frequency selection of weather radar is a performance compromise between precipitation reflectivity and attenuation due to atmospheric water vapor. Some weather radars uses doppler shift to measure wind speeds and dual-polarization for identification of types of precipitations. [3] [4] Weather radar; Wind profilers; Millimetre cloud radar ...
Doppler effect. The emitted signal toward the car is reflected back with a variation of frequency that depends on the speed away/toward the radar (160 km/h). This is only a component of the real speed (170 km/h). The Doppler effect (or Doppler shift), named after Austrian physicist Christian Doppler who proposed it in 1842, is the difference ...
A NEXRAD weather radar currently used by the National Weather Service (NWS) is a 10 cm wavelength (2700-3000 MHz) radar capable of a complete scan every 4.5 to 10 minutes, depending on the number of angles scanned, and depending on whether or not MESO-SAILS is active, which adds a supplemental low-level scan while completing a volume scan.
NEXRAD or Nexrad (Next-Generation Radar) is a network of 159 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 ...
The pulse width ( ) (or pulse duration) of the transmitted signal is the time, typically in microseconds, each pulse lasts. If the pulse is not a perfect square wave, the time is typically measured between the 50% power levels of the rising and falling edges of the pulse. The pulse width must be long enough to ensure that the radar emits ...
Dynamic frequency selection. Interference by 5 GHz Wi-Fi seen on Doppler weather radar. Dynamic Frequency Selection ( DFS) is a channel allocation scheme specified for wireless LANs, commonly known as Wi-Fi. It is designed to prevent electromagnetic interference by avoiding co-channel operation with systems that predated Wi-Fi, such as military ...
A pulse-Doppler radar is a radar system that determines the range to a target using pulse-timing techniques, and uses the Doppler effect of the returned signal to determine the target object's velocity. It combines the features of pulse radars and continuous-wave radars, which were formerly separate due to the complexity of the electronics .