Yes, if you see the sweep going around, its live. NBC12's First Warning Doppler Radar is actually on an 80 foot tower right beside the NBC12 transmitting tower at our studio complex on Midlothian Turnpike. Most importantly, ours is operated from a control panel in our Weather Center. And we have recently added Storm Track software which allows us to draw a map projecting where a storm will go and when it will arrive. No, not all radar is doppler radar.
Regular radar detects rainfall and can tell how much rain is falling at any given location.
Doppler radar does that AND can detect how much the rain is being blown around by the wind. This makes doppler radar especially helpful in spotting severe thunderstorms and other damaging weather. On our radar display, this turbulance is shown as purple. The biggest limitation to radar is distance. Because the earth is round and radio-waves travel in a straight line, weather radar is most effective close to the transmitter.