One of the most important things for aviation in a war is a stealth approach to a target. However, it was extremely difficult to pull off such a trick already in the Second World War due to the rapid development of radars and air defense systems. Indeed, it was during this conflict that the visual method of detecting enemy aircraft actually completely gave way to automated search systems. Aviation, in turn, began to go to additional tricks in order to remain unnoticed as long as possible.
During the Second World War, radar stations were widely used to detect aircraft. The general essence of this method of detecting objects is quite simple: the station emits radio waves that are reflected from the cherished object and fly back, where the receiver catches them. Needless to say, a radar that allows you to find aircraft tens and even hundreds of kilometers away is as much a leap in terms of a visual detection method as the invention of an internal combustion engine in relation to jogging.
Radars quickly became a major problem in military aviation. In order to remain unnoticed for as long as possible and successfully complete the assigned task, the pilots and their command had to invent new tricks. The first thing we started was to fly as low as possible using the terrain folds. However, not every plane could deal with such a luxury. And on July 24, 1943, the Royal Air Force of Great Britain, during a night raid on Hamburg, used a new method of countering the radar - "Windou".
Windou is a method of suppressing enemy radars by dropping huge amounts of foil strips (metallized paper). On approaching the bombing zone, British aircraft scattered these stripes in the sky. As a result, they (just like planes) began to reflect radio waves, creating huge "flashes" on the screens of German radars, bright empty areas that interfered and did not allow aircraft to be detected. The effect of using the new method was simply stunning, the Reich radar stations were practically paralyzed.
As you might have guessed, the Windou technique became the forerunner of modern dipole reflectors, which are still used in aviation today along with infrared countermeasures (heat traps). The principle of operation of dipole reflectors has practically not changed since 1943. These are all the same strips of foil or pieces of metallized fiberglass that are fired from an airplane in bundles in order to create radio interference.
At one time, reflectors made it possible to reduce the losses of British aviation by 4 times. It is noteworthy that at first they could not understand what was happening in general. This continued until one of the farmers brought strange strips of foil to the soldiers, which fell on his plot at night. However, just as "Windo" at one time became the answer to the rapidly developing radars, new methods of detecting aircraft became the radar's answer to the creation of dipole reflectors. Nowadays, it is possible to deal with this kind of interference with varying degrees of efficiency by using radio waves of different lengths.
If you want to know even more interesting things, then you should definitely read about because of what the German destroyed tanks "Tiger" guns are directed down.