Figure 2a: Non-polarimetric radars, such as NEXRAD, transmit and receive only horizontal pulses of radio waves. Therefore, they measure only the horizontal dimension of cloud and precipitation particles.

Figure 2b: Polarimetric radars transmit and receive both horizontal and vertical pulses of radio waves. Therefore, they measure both the horizontal and vertical dimensions of cloud and precipitation particles. This additional information leads to improved predictions of precipitation type and rate.