Scientists at the University of Oklahoma at Norman are working on a new type of radar that is digital and seems to have great future potential. I have personal experience with the operations in Norman, Oklahoma that are in conjunction with the National Severe Storms Laboratory (NSSL) in Norman.
I visited the facility back in the mid 1970s during a nationwide tornado seminar for television weather forecasters. I discussed this in a previous article a few years ago. Here is a segment from that article explaining Doppler Radar.
Before I can explain how the radar works we need to the definition of the term “Doppler Effect.” We have to go back to 1842 in Prague, what is now the capital of the Czech Republic, and an Austrian Physicist named Christian Doppler who first proposed the effect or shift. The “Doppler Effect” is the change in frequency of a wave for an observer moving relative to its source. What the heck does that mean?
One of the simplest demonstrations of the “Doppler Effect” is the variation in sound when you hear a car or railroad train that is far away and as it gets closer the sound gets louder and the pitch changes to the loudest as it is nearest you and then decreases again as it move away from you. That forms the basis for why Doppler Radar is so different from conventional radar. Doppler Radar is a more recent invention that dramatically increases the effectiveness of radar. The main difference with Doppler radar is that it not only sends a microwave beam out, but it also measures the frequency of the wave as it leaves and again while it is returning. It gives the meteorologist a three dimensional look at the sky similar to a slice of pie which reveals what is inside the pie itself. The Doppler radar development project was given the acronym NEXRAD standing for NEXt Generation RADar.
In the earlier article I used the explanation given to me a few years ago by the scientist who explained the new radar system to the group back in the 70s. His name is Dr. Richard Doviak. “Doppler weather radars typically transmit microwave radiation in bursts of short duration. These radars are called pulsed-Doppler radars to distinguish them from those that emit continuous waves such as radars used by police to detect the speed of automobiles.
Pulsed-Doppler radars can measure both the range (r) and radial velocity (v) of scatters.” ” The US National Weather Service (NWS) network of Doppler weather radars emit..pulses of 10-cm wavelength radiation similar to that used in microwave ovens. These radars are called WSR-88Ds, where WSR is an acronym of Weather Surveillance Radar. The number 88 denotes the year the contract was issued for a limited production and testing; the first unit for routine operation was installed in late 1992 and the last radar in a network of about 160 radars was installed in 1997; the letter D represents the Doppler capability; polarimetric upgrades were completed in 2013.”
Back to the University of Oklahoma’s Radar team developing the portable digital radar unit for the US Navy. The University’s Advanced Radar Research Center (ARRC) received a $5.4 million dollar grant from the U.S. Department of Defense (DOD) to develop an all-digital polarimetric phased array mobile radar testbed that can increase public safety outcomes like air traffic surveillance and control and weather weather monitoring. The team is responsible for all aspects of the project, including electrical and mechanical design, mechanical assembly, thermal designs, data and processing control, a chiller system, truck with factory integrated generator, array positioner, enclosure and truck modifications.
According to the University of Oklahoma’s web news article titled “OU Radar Team Testbed” written by Jana Smith Caleb Fulton, professor of electrical and computer engineering at Gallogly College of Engineering was quoted explaining “The all-digital radar can do what most radars can not do, which is why the U.S. Navy is extremely interested in the capabilities of this mobile radar testbed.
What really makes the digital radar so special is that it shows a more detailed image and it is a continuous stream of data instead of the interrupted Pulse-Doppler radar. As this portable polarimetric phased array digital radar unit is mass produced and improved it could represent a giant step in radar technology.
Let me know what you would like me to talk about or explain. You can email me at: [email protected].