Morse Code of Weather: important hardware components of weather radars and how maintenance is performed

BISMARCK, N.D. (KFYR) - Over the past two weeks, we’ve shown you the basic operations of weather radars and how they tilt to a variety of different angles to get a complete 3-D picture of precipitation in the atmosphere.

But there are plenty of complex components to weather radars that allow them to operate and detect precipitation 24/7/365.

Inside a special housing at the center of the radar is the motor (called the azimuth drive motor) that controls the spin, or rotation, of the 28-foot wide radar dish. But you have to get the signal up to the radar on something that is constantly turning 360 degrees without twisting wires around.

The way this is achieved is through the slip ring assembly. Inside the special housing at the center of the radar is a box where the signals are transferred up to the spinning part of the radar through metal contact. Metallic layers are stacked up on each other with each tidbit of information that needs to go up to the radar on a single layer, and small metal bushes transfer the data. This also gives the spinning part of the radar power.

Farther up, is the elevation motor that moves the radar up and down to the different elevation angles we talked about last week. And there are weights to perfectly balance the radar structure as a whole.

Back down on the ground, at the base of the radar, is a backup generator run on diesel that can supply full power to the radar if power from the grid happens to go out.

To service this complex machine, the National Weather Service employs technicians that are on call 24/7 in case anything goes wrong.

Chauncy Schultz, science and operations officer at the Bismarck National Weather Service, said: “At least once a month, they go out and do maintenance checks, things like changing the oil, and things like that. It is a piece of machinery, just like your car. So we have highly trained technicians, skilled technicians that provide at least monthly maintenance to the radar, more often if needed. If something happens to break, they make an immediate fix to it.

Since the radar was originally installed in 1994, we’ve only taken the “golf ball” or the “soccer ball” off one time. That was actually about a year and a half ago. And the reason that we did that is part of what we call the “Service Life Extension Program.” So, the radar itself has been installed for going on 30 years now, but we’ve improved the parts in it. We continue to improve and extend the life cycle of the radar to provide life-saving information.

Thankfully, our radar has never been damaged, but other radar sites certainly have been. Most recently, the Rapid City, South Dakota radar last summer was pummeled with really large hail and strong winds. And just like anything on your house that might be made out of fiberglass, it was damaged. And so the repair process for that takes time.

In extreme cases, with hurricanes, for example, there have been some instances when the radars have been totally destroyed. In that case, to completely rebuild a radar, it takes a long time, many, many months to rebuild a radar. Thankfully, that’s only happened a very small number of times in history.

There is actually a repository of spare parts, if you will, to help rebuild radars if necessary. But it takes time and process to completely rebuild one from scratch.”

Next week on Morse Code of Weather, we’ll talk about how weather radars detect the speed and direction of particles to determine rotation within thunderstorms.

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