Ever since Louis Bleriot made the first flight across the English Channel, the Britons realized that the possibility of being attacked from the air became a reality. It is this historical event that caused the Ministry of Defense to start developing an air defense system known as the “Chain Home Network”. The primitive stages of this defense network comprise of large ‘hearing blocks’ where the Royal Air Force (RAF) would have someone sit in front of the concrete blocks (above Figure 1) and listen for the sound of approaching airplane armadas. This method did produce results, however, by the time the personnel was able to hear the airplanes and relay it to command center, it was already too late for the RAF to launch an effective counter response. Hence, the Ministry of Defense decided to use another system, which they named the “object-detection system”, but little did they know that it is precisely this system that would turn the tides in favour of the Brits and change the fate of the war during the Battle for Britain. Many historians throughout the world till this day believe that the United Kingdom was key to putting Hitler’s ‘unstoppable’ Blitzkrieg (or lightning war) to a halt in Western Europe. Although what many previously did not realize is that the key component in stopping the infamous Luftwaffe during the Battle of Britain and effectively preventing the invasion of Britain was in fact an intangible system. This system had a classified name: “Radio Detecting and Ranging” object-detection system; or in today’s terms, it’s commonly known as RADAR.
I knew that the RADAR aided the British in stopping the Luftwaffe from my previous knowledge in the history of World War Two, but how did the RADAR do it? Well, the RADAR transmits pulses of radio waves or microwaves with very long wavelength that bounces off (or reflects off) of any object in their path. Regardless of the size of the object, it returns a tiny part of the wave energy to a radar dish or antenna (shown above) that’s usually located at the same site as the transmitter. The components of RADAR are actually quite simple; it has a transmitter, a waveguide, a duplexer, a receiver, and an electronic station. The transmitter generates the radio signal with an oscillator, which emits the pulses from a radar (similar to that of a sonar sound you hear in the submarines) and the duration is controlled by a modulator (charges up with high voltage to release the pulse which is sent out through the antenna). The waveguide links the transmitter to the antenna, which broadcasts the radio signal. The duplexer is a switch between the antenna and the receiver or transmitter for the signal when the antenna is used in both situations. The radar receiver, receives the signal that is reflected off the object hit by the pulse emitted from the transmitter. This signal is then sent back to the electronic station for interpretation (commonly a visual image of that object on a circular screen showing the location of that object in Figure 3 shown below). I know this to be true because in my Phyiscs class I’ve learned that this concept of radar is valid and proven. So, by being able to detect the German bombers way before they reached Britain, the RAF was able to effectively assemble a counter-attack strike force against the bombers.
In figure 4, it shows the radar (mounted on the top of the AWAC airplane). The radar emits radios waves 360 degrees and when these radio waves ‘hit’ an object (e.g. airplane, flock of birds, etc.) the radio waves are reflected back to the airplane. The amount of time the radio waves take to travel back to the airplane is how far the object is from the radar source. This was the basic functioning of radar. The invention of radar is important then and now because if it weren’t for the development and use of RADAR in World War Two, then a lot more British civilians in London would have been killed and potentially the Luftwaffe might not have been harassed by the RAF on their bombing runs to London, and the Germans could’ve potentially invaded Britain. So, from a British military perspective, the invention of radar not only helped the RAF defend the British mainland but also aided them in bombing runs by methods of triangulation or honing in on a target to get the British bombers on track and hit their targets during blackouts at night. On the contrary however, from a German military perspective, the invention of the radar by the British became a nuisance and a great cost to the Luftwaffe. This is because they now no longer have the advantage of a surprise attack, due to the long detection ranges of the radar, and they have to defend the German cities not only from the American daylight bombing runs, but now from the British night bombing runs as well.
This knowledge and use of radar is also important to modern day times because little do we know that we actually rely on radar almost every single day. Radar has expanded its usage by being placed on airplanes and used for detecting the position of airplanes by air traffic control. Otherwise without radar and with thousands of airplanes flying over the continental US at the same time, it is very likely to crash into another airplane. Another use of radar today is to detect weather patterns and climate change, e.g. formation of a tropical storm/ hurricane, or seeing the position of storm clouds, etc. Now the technology of radar has gotten so advanced that it’s now instead of just detecting objects, radar has now been used to jam other radar in order to make an object become ‘invisible’. So, a major implication from this is that even though radar was designed intentionally for military purposes, throughout the century it has expanded into other areas. This goes to show how such a major invention in World War Two that potentially changed the tide in the Battle for Britain, has found new purposes and adapted in today’s world.