![]() ![]() You have most likely experienced the "Doppler effect" around trains.Īs a train passes your location, you may have noticed the pitch in the train's whistle changing from high to low. ![]() This Doppler effect was named after the Austrian physicist, Christian Doppler, who discovered it. The phase of the returning signal typically changes based upon the motion of the raindrops (or bugs, dust, etc.). The ability to detect the "shift in the phase" of the pulse of energy makes NEXRAD a Doppler radar. Learn about the different scanning modes of the Radar here The remaining 59 minutes and 53 seconds are spent listening for any returned signals. When the time of all the pulses each hour are totaled (the time the radar is actually transmitting), the radar is "on" for about 7 seconds each hour. NEXRAD spends the vast amount of time "listening" for returning signals it sent. This process of emitting a signal, listening for any returned signal, then emitting the next signal, takes place very fast, up to around 1300 times each second! Computers analyze the strength of the returned pulse, time it took to travel to the object and back, and phase, or doppler shift of the pulse. This reflected signal is then received by the radar during its listening period. Note: it's a small fraction of the emitted energy that is scattered directly back toward the radar. If the energy strikes an object (rain drop, snowflake, hail, bug, bird, etc), the energy is scattered in all directions (blue). The radar emits a burst of energy (green in the animated image). Weatherbug app was a better choice because one could miss out on all the adds and videos, one could just get the weather.NEXRAD (Next Generation Radar) obtains weather information (precipitation and wind) based upon returned energy. When I needed more, I went to the web site with all the adds. I liked Weatherbug because I could get what I wanted. Will consider again if map is returned to normal. Sent the app to the trash after downloading it again, the current version is the problem. The web site is good, just as add heavy as the Weather Channel, but this app gave a instant convienience others do not give. The tool bar click was great, gave one what they wanted. Tried it a while ago, where the map should have been, were choices which directed one to their web site. Liked the fact that one could access the app and THEN if one wanted too, access the web site with all their adds. Great for finding out the current weather. Worked great, great for finding out what was happening outside before going out. Receive all National Weather Service watches and warningsīe prepared.Get notified of severe weather 50% faster with our exclusive Dangerous Thunderstorm Alerts. ![]()
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