Radar Radio Detection and Ranging Radar How it works Radar What it Measures Echo the reflection of microwaves off of the rain drops a k a Strength of return signal or echo proportional to the of drops proportional to the size of the drops What does it measure Frequency of collection How are the data viewed 41 4 hail near Midland Odessa Texas 4 23 08 Doppler Effect and Radar The easiest way to understand the Doppler effect is with sound waves Hears a lower pitch sound Hears a higher pitch sound If a rain drop is moving toward or away from the radar then the frequency and phase of the echo it will make will be higher or lower From this change in frequency and phase we can determine the wind speed and direction Red precip if being blown away form the radar antenna Green Blue precip is being toward the radar antenna Radar Radar Operation Modes Radar echoes from precipitation Radar gets echoes from birds bugs dust turbulence in moisture content and even light snow Commonly called ground clutter Radar Estimated Precip Adds up the echoes over time great for monitoring flooding potential Observed Precipitation last 90 days Percent of Normal