What is Dual-Pol Doppler Radar?

Dual-pol doppler radar is a relatively new upgrade to the original doppler radar technology and towers that the National Weather Service offices around the U.S. use. The upgrade helps better determine the type and intensity of precipitation and how much may fall. It can also help tell the difference between smoke, bats, birds, bugs, and confirm that tornadoes are on the ground causing damage.

So what is the difference between regular doppler radar and dual-pol doppler radar? Radars send out short pulses of electromagnetic wave fields that bounce off the different types of precipitation and return back to the radar dish. A computer will analyze the signal returned to determine the type of precipitation falling. Original doppler radar would just send out a horizontal signal. This signal only going in one direction would make it tough to tell the difference between precipitation types.

With dual-pol doppler radar, the pulse of electromagnetic wave fields is sent out in both horizontal and vertical directions. We now get a two-dimensional picture and the computers analyzing the signal can better measure the size and shape of the object the signal bounced off of.

With dual-pol doppler radar, we have seen a significant improvement in rainfall estimation, precipitation classification, data quality, and weather hazard detection.

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