Robert Watson-Watt

Apr 11, 2021

The world wars were a time of great destruction and catastrophe. This necessitated scientific and technological innovations that would help shorten the war. One such invention is RADAR technology, pioneered by Sir Robert Alexander Watson-Watt. He was born in Angus, Scotland in 1892 and attended the Damacre Road School. After getting a BSc in Engineering from the University of St. Andrews at University College of Dundee where he would later teach, his professor pushed him towards the study of radio.

Sir Robert Alexander Watson-Watt

He started his career in the Met Office of the UK where he worked as a meteorologist, as no jobs were there in communications. In his discoveries he noted that when lightning strikes, the air around it gets ionized and emits a radio signal. He could pick up this signal and read it from quite a distance. This discovery helped in early warning systems to warn pilots of nearby thunderstorms. His work with aircrafts further continued, with him suggesting that Cathode Ray Oscilloscopes should be used in aircrafts as a way of plotting electrical signals on a screen.

By the 30s, he had worked his way up the ladder to land a position in a special wartime research committee set up by the Air Ministry. His experiments with early thunderstorm warning proved to be vital in WW2 for the British army. As growing suspicions arose about the Nazis building a “death ray”, Watson-Watt was asked to construct a weapon to destroy the aircraft before they could attack, as aircrafts were too slow and anti-aircraft guns were ineffective. His colleague Wilkins proved the death ray to be a logical impossibility. However, in these experiments, he discovered that shortwave communications could be interfered with by aircrafts. He used Adcock antennas (an array of antennas) that measured phase difference between two signals to pinpoint the direction from where the interference came. As he used radio waves, he called it RADAR or Radio Detection and Ranging.

Working of RADAR

His work kept getting fast tracked, going from reusing parts to make small RADAR units to running tests with multiple stationary radio towers in Bawdsey, on the coast of Eastern England. With the success of the ranging as well as transmission of this information back to the RAF meant that Nazi zeppelins no longer posed a threat and could be detected before they could be seen. In fact, the “chain home”, a ring of early warning RADAR stations built by the British prevented the need for multiple RAF planes to be in flight all the time and would take off only if the RADAR picked something up. These RADAR stations were the turning point in the Battle of Britain, a large-scale attack by the Luftwaffe during WW2.

The first RADAR unit built by Sir Watson-Watt

RADAR technology has developed and expanded its scope over the years but it still uses Watson-Watts concept of detecting radio waves. In aviation and for maritime, RADARs perform similar functions like control of traffic, detection of obstacles, accurate weather information and precise location. Back then, he could only detect lightning. Now, using RADARs, meteorologists can detect wind and rain. They are also used in early warning systems for natural disasters like cyclones and thunderstorms.

Watson-Watt was elected a fellow of the Royal Society for his work and died on 5 December 1973. Even though his work massively contributed to the triumph of the British over the Nazis, he is often given less credit than he deserves. Hertz and Hülsmeyer were two such scientists upon whose work Watson-Watt developed on, but get more credit for. Hertz first discovered that EM waves could be transmitted and reflected by certain materials. Hülsmeyer worked this into a ranging device that could send radio waves in water that would bounce off surfaces and return back, thus indicating the presence of a ship. These discoveries undoubtedly paved the way to his work, but he should not be overshadowed by his colleagues and hopefully this article demonstrated why that is.

An article by Rahul Tripathy

Disclaimer: the pictures in the article are for illustration purposes only. Neither the writer nor PHoEnix has a claim over them.



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