On this date in 1935, Radar was tested in Orfordness, Suffolk, the first time radio-based detection and ranging was shown in Britain. The first target that was detected: a flying boat 17 miles (27 km) away. 10 things you might not know about radar.
The word radar is an acronym for "radio detection and ranging" which was coined in the early second world war.
Radar uses Radio waves to determine if something, like a ship, Submarine or aircraft, is out there when you wouldn’t be able to see it, how far away it is and how fast it is moving.
It does this by sending out short bursts of radio waves, or pulses. Some of these will bounce back if they hit something. The waves which bounce back are known as echoes. By measuring the time it takes for a pulse to leave the radar and return as an echo, the system can calculate the distance to the object. If the object is moving, the frequency of the returning waves changes slightly, which helps the radar figure out its speed. This is called the Doppler effect, which is the reason why a siren from an ambulance sounds slightly different when it’s moving away from you rather than coming towards you. Radar is similar to the echolocation that Bats use.
Physicists knew about the concept of radar as far back as 1886 when Heinrich Hertz proved that electromagnetic waves (like radio waves) exist, and that they could travel through different materials and bounce off metal surfaces.
In the early 1900s, a German inventor named Christian Hülsmeyer created the telemobiloscope, a device which could detect ships in Fog up to 3km away. While it did help prevent collisions in poor visibility, it didn’t tell you exactly where the other ship was.
Radar technology grew very fast during World War II. Eight countries were secretly working on developing it: the United Kingdom, Germany, the United States, the USSR, Japan, the Netherlands, France, and Italy.
Some historians believe it was radar, not the atomic bomb, which helped the Allies win the war.
After the war, other uses for radar were developed besides finding things to shoot at. It’s used for navigation and making air and sea travel safer; it’s also used in weather forecasting, tracking animals and Birds and in medicine. The flapping of a bird’s wings distinguishes it from aircraft, and it’s even possible to tell one type of bird from another using radar.
Police use radar guns to measure the speed of cars on the road. One person who was caught and fined using one of these devices was Sir Robert Watson-Watt, who was one of the people who developed radar in the early days of the war with the aim of collaborating with the United States to beat the German military.
The cathode-ray tube has been the preferred technology for displaying radar information ever since the early days. Radar displays have developed alongside computer and television screens so they keep getting better.
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