To detect enemy aircraft, Scottish physicist Robert Alexander Watson-Watt developed and introduced radar, an acronym for Radio Detection And Ranging technology. It was invaluable in protecting Great Britain during WWII against German air raids, both day and night, and in all types of weather. He had studied at University College, Dundee, part of the University of St. Andrews in Scotland. It was during Watson-Watt's first job, which involved designing devices to locate thunderstorms for the Scottish Meteorological Office, when he coined the term "ionosphere" to describe a layer of the atmosphere. It became the basis of his subsequent work in radio detection at Britain's National Physical Laboratory. Watson-Watt also developed a cathode-ray direction finder to study atmospheric phenomena, did research in electromagnetic radiation, and invented other devices for flight safety. He was knighted in 1942 for his role in the development of radar.