What You Never Knew You Wanted To Know About Radar
You probably use radar every day. Learn more about it.
Radar is one of the most important inventions ever. From tracking airplanes to helping predict the weather, radar is a part of your everyday life. But what exactly is radar, how does it work, and where is it used?
Simply put, radar is radio waves—the same thing that beams music into the car, makes wi-fi work, and connects your phone to the world. The U.S. Navy coined the term RAdio Detection And Ranging. Instead of beaming music or voices, it’s a repeated signal. When that signal comes back, the radar station can calculate the bounced waves to determine the location and size of the object.
You actually use radar every day. If you’ve ever checked the weather and they show a map with a line spinning and clouds moving, that is radar. If you’ve ever flown on a plane, there is a radar in the nose of the plane to help the pilot see through clouds. The airport has another radar to help track the planes as they come and go. If your parents get pulled over for speeding, radar was probably how the police knew they were speeding.
But there is another radar that you might use every day: the microwave.
So how did a technology designed to track enemy aircraft turn into the thing you cook your mac and cheese in? The short answer is: a lot of accidents.
Just before WWII, scientists at Westinghouse noticed short wave radio transmitters could heat up food placed between them. There were a few problems with short wave transmitters cooking food: they were huge, they were dangerous to be around, and WWII broke out.
After the war, Percy Spencer was working with Raytheon to improve radar using microwaves instead of short waves. He noticed a chocolate bar in his pocket melted. So, then he tried popcorn. Then an egg. The microwave as we know it was invented!
The first microwave was called the Raytheon Radarange. They cost $5,000 at the time, equivalent to $57,000 today. And they used three times as much power as a modern microwave, were over five feet tall, and weighed 750 pounds!
Another fun fact about radar is that you used to be able to hear it until 1989. During the Cold War, Russia built a system known as Duga or, to amateur radio operators, the Russian Woodpecker. Duga was built as an early warning system against nuclear attacks. It was so powerful, it interrupted radio signals around the world. It was referred to as the Russian Woodpecker because the interruption was a constant ticking in the background, like the sound of a woodpecker on a tree.
The reason they knew it was Russian is that you can triangulate radio signals. That means you can measure them and calculate where they are coming from using at least three receivers. Radio waves travel at a set speed—the speed of light. So if you know the location of three receivers and the difference in time it took each to receive a signal, you can calculate how far away the signal is from each one. If you draw a circle around each receiver location, the point where all three meet is where the transmitter is located.
Whether you are warming up an after-school snack, flying, or hearing some interference on a radio, radar is a part of our everyday lives. If you want to learn more about it, you can look up how to become a Ham radio operator and get your license. It might not be radar, but it will help you understand some of how it all works. And if you get your own radio, you can talk to people all over the world!