Radar or radio detection and ranging, is a device that is used extensively on airplanes. Just like other radar systems, airplane radar also contains a high frequency radio pulse that is transmitted for a short time phase during which the pulse reaches the highest altitude. When any kind of solid obstruction comes in the path of the transmitted pulse, it strikes the object and gets reflected back to the radar, helping in the object’s detection along with its exact distance from the radar.
The history of radar dates back to World War I, when a number of scientists contributed to its invention. The most prominent among them was a Scottish physicist named Robert Watson-Watt, who was appointed by Britain’s Meteorological Office to facilitate the use of radio waves to detect approaching storms during World War I. However, it was only during World War II that Watson-Watt, along with his assistant, thought of using the technology for detecting approaching enemy aircrafts or other such obstructions.
The working of radar system on an airplane begins from the time it’s installed onboard. The radio waves emitted from the radar are very similar to those of light and are transmitted by equipment in its system known as magnetron. A magnetron transmits microwaves composed of wavering patterns of electrical and magnetic energy, traveling at a speed almost equivalent to light waves but with longer wavelengths and higher frequencies. Generated waves are forced in to the air by an antenna that works as a transmitter. These curved radar antennas focus the waves into precise, narrow beams and even rotate to detect movements over an expansive area. The waves travel from the antenna at light speed and travel continuously till they hit an obstruction, and some of them are bounced back to the antenna. The traveling speed of these waves needs to be high, as signals need to travel faster than the obstruction. As radio waves travel at light speed, they are faster than most of the objects.
The antenna is both the transmitter and receiver of the radar. First it transmits the waves and then it waits for the reflected waves, which are then directed to electronic equipment where they are processed and displayed in a consequential manner on a television-like screen overlooked by a human operator. Moreover, the radar equipment is so designed that it displays only relevant reflections, filtering those from other sources such as ground, buildings etc. The radar enables the operator to view nearby ships and planes, their location as well as speed and direction. An airplane radar is an extremely important device during foggy conditions, as bad weather cannot obstruct radio waves and thus is highly beneficial in helping an airplane easily navigate.
The radar technology has come a long way since the time of its invention. However, the most noteworthy advancement in radar technology has been the phased-array radar wherein hundreds of tiny antennas are geometrically positioned to correlate the transmitted and received signals in terms of phase. Moreover, stealth technology has also been developed so that enemy radar cannot spot the aircraft carrying missiles and bombers. The stealth technology is designed on a special technology that allows it to scatter or absorb beams of radio waves. There are also spy airplanes which are so efficient that while they show on the enemy radar, it appears to be similar to the size of a swift bird, allowing it to pass speedily and undetected.
“Radar” Science World: https://scienceworld.wolfram.com/physics/Radar.html
“How Radar Works” Explain That Stuff: https://www.explainthatstuff.com/radar.html
Radar Display. (Supplied by Avsim; Public Domain; https://www.avsim.com/pages/0204/lomac/F15Easy%20Radar.jpg)