Most people have heard of the term “radar waves” and are familiar with the idea that radio waves use radar to somehow “detect an object” that is out in the distance or out in an area somewhere.
Fans of submarine movies know that sonar (SOund Navigation and Ranging) uses sound to either communicate with or detect other ships or submarines on or under the surface of water. Using the distance it takes for that sound to reach the object (and some reasonable mathematical calculations) the radio operator could report to the captain not only the distance of other ships, but also their course, speed, and depth – after several measurements were taken.
Today, for the most part, a majority of people accept the fact that there are all kinds of waves out there, radio and microwaves included, bouncing all around us – indeed through us… and these waves make all sorts of things work. Microwave ovens, cell phones, Wi-Fi, cat scans, x-rays, and numerous other devices – use invisible (to the naked eye) waves to somehow “just work”.
And as long as these waves don’t cause harm, (and many will always question that) and the devices work, the specifics of how they function are not necessary.
Nonetheless, a basic comprehension of radar is possible without flashbacks to high school physics!
What makes radar technology difficult for many people to understand, is that – although radio waves and microwaves (two types of electromagnetic waves) are very small and are, for the most part, not seen, they do transport energy – just like ocean waves and sound waves. Ocean and sound waves require matter in order to transport energy, while electromagnetic waves do not.
Think of the enormous power of the sun; while ultraviolet rays (another form of electromagnetic wave) carry no matter, they are capable of severe burns from 93 million miles away in a very short time!
Further, radio waves can pass through vacuums, which allows them to travel through space – making the use of satellites possible. All electromagnetic waves travel at the speed of light (or so close to it, that any difference is inconsequential in virtually any application), a fixed number equal to 299,792,458 meters per second (take a moment to think about how really fast that is… in feet if need be… 1 meter = 3.28 feet!). This speed, almost always referred to in science as the letter “c” for example, E = mc2…
Albert Einstein’s theory of special relativity, shows that increased mass, “m” of a body comes from the energy of motion of that body, i.e., the kinetic energy, “E” divided by the speed of light squared (c2). That sounds fairly simple and straightforward, but Albert Einstein is still many generations ahead of his time!
The figure above shows the principle of a radar system emitting a wave and receiving the reflected wave that was reflected by an object (target).
The learn more about the radar principle, click here.