The development of radar for meteorology

1864
British physicist James Clerk Maxwell develops equations governing the behaviour of electromagnetic waves, including the laws of radio-wave reflection.

1887
German physicist Heinrich Hertz shows that radio waves can be transmitted through different materials, and finds a way to measure their speed.

1901
Guglielmo Marconi transmits radio waves across the North Atlantic.

1924
Sir Edward Appleton measures the height of the ionosphere with radio echoes.

1934
A 'death ray' to disable machines and people is suggested, but destruction at a distance is not thought possible. However, energy reflected by objects such as aircraft should be detectable at useful ranges.

1935
Sir Robert Watson-Watt develops the UK's first practical radar system.

1939
The UK has a chain of radar stations located along the south and east coasts to detect attack from both air and sea.

1940s
Wartime radar operators find additional echoes appearing on their displays. These are found to be from precipitation such as rain or snow - physicists had not appreciated the sensitivity of radar.

1960s
Further development of radar for weather applications is slow, but in the late 1960s the Met Office collaborates with the Royal Signals and Radar Establishment to use radar for measuring precipitation, and to generate imagery from the data.

1970s
A national weather radar network is planned, in co-operation with the water industry, with the first two installations located in the north-west of the UK and in the London area. This enabled forecasters and other users of weather radar to fundamentally reassess precipitation patterns and spawned some new ideas and theories in weather forecasting.

1980-90s
The use of radar images becomes more extensive allowing users (e.g. the military, Environment Agency) to adapt behaviour, procedures etc. in line with the weather