1. A little history

The first applications of radioelectricity were in telecommunications, followed by radio navigation. At the turn of the century, however, pioneers were already considering the possibility of using electromagnetic waves to detect the presence of metallic objects.

It was the military need for air and sea defense that was the main driving force behind this new technique from the 1930s onwards. The word Radar itself, now universally adopted to designate equipment meeting these requirements, is a code name officially adopted by the U.S. Navy in November 1940, short for Radio Detection And Ranging.

But the origins of radar go back much further.

The first concrete experiment was carried out by Christian Hülsmeyer, who patented his Telemobiloscope in 1904. But it wasn't until the 1920s that the idea resurfaced.