My locations. No advertising, more exclusive weather content: click here! US Doppler Radar. Change map selection Hide map selection. Change radar location Hide radar location selection. Lincoln Best radar location. Change radar product Hide radar product selection. Select the desired radar product. Year Time Auto-Update active. Base reflectivity dBZ. US Doppler Radar.
Change map selection Hide map selection. Change radar location Hide radar location selection. Lincoln Best radar location. Change radar product Hide radar product selection. Select the desired radar product. Year Time Auto-Update active. Base reflectivity dBZ. A few tips on reflectivity data: In cold climates during the winter months, actual dBZ values rarely exceed Bright reflectivity returns that are stationary and appear during both calm and inclement weather are usually land-based obstructions such as mountains, trees, or especially wind farms nothing gets electromagnetic signals confused like spinning metal blades!
This helps meteorologists detect near-ground wind shears, which are dangerous to aircraft. Doppler radar technology also enables meteorologists to forecast the location and severity of weather with greater accuracy, which has resulted in improved public safety.
The radar dome, which many people say looks like a big soccer ball or volleyball, protects a foot-wide antenna. The antenna is made up of a transmitter and a receiver. The transmitter samples the environment by sending out a pulse of energy that reflects off objects like raindrops and scatters the energy pulse in all directions. Part of the energy reflects back to the antenna and is measured by the receiver. The returned energy is then processed into three types of base data: reflectivity, velocity and spectrum width.
Reflectivity is calculated from the fraction of signal that is reflected back to the radar. Velocity is calculated by measuring the Doppler shift from one pulse to the next to determine the speed with which the object is moving toward or away from the radar. Spectrum width is calculated based on how much variation there is in velocity readings in a given area.
Additionally, a host of derived products are computed from the base data. These include precipitation estimates, as well as severe weather parameters like tornadoes, hail and heavy rain. During a potentially hazardous weather event, many of these products will be examined by a forecaster to make decisions on issuing warnings. The radar does not sample the entire atmosphere at once. Rather, the antenna makes a degree rotation pointed at a particular elevation angle, then changes elevation and completes another rotation.
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