Editing Radar (section)

===During World War II===
{{main|Radar in World War II}}
[[File:East Coast Chain Home radar station CH15176.jpg|thumb|East Coast [[Chain Home]] radar operators in England]]
A key development was the [[cavity magnetron]] in the UK, which allowed the creation of relatively small systems with sub-meter resolution. Britain shared the technology with the U.S. during the 1940 [[Tizard Mission]].<ref name="Angela Hind-2007">{{cite news |url=http://news.bbc.co.uk/1/hi/sci/tech/6331897.stm |title=Briefcase 'that changed the world' |publisher=BBC News |author=Angela Hind |date=5 February 2007 |access-date=16 August 2007 |quote=It not only changed the course of the war by allowing us to develop airborne radar systems, it remains the key piece of technology that lies at the heart of your microwave oven today. The cavity magnetron's invention changed the world. |archive-date=15 November 2007 |archive-url=https://web.archive.org/web/20071115140606/http://news.bbc.co.uk/1/hi/sci/tech/6331897.stm |url-status=live }}</ref><ref>{{cite news|last1=Harford|first1=Tim|title=How the search for a 'death ray' led to radar|url=https://www.bbc.co.uk/news/business-41188464|access-date=9 October 2017|work=BBC World Service|date=9 October 2017|quote=But by 1940, it was the British who had made a spectacular breakthrough: the resonant cavity magnetron, a radar transmitter far more powerful than its predecessors.... The magnetron stunned the Americans. Their research was years off the pace.|archive-date=9 October 2017|archive-url=https://web.archive.org/web/20171009003404/http://www.bbc.co.uk/news/business-41188464|url-status=live}}</ref>

In April 1940, ''[[Popular Science]]'' showed an example of a radar unit using the Watson-Watt patent in an article on air defence.<ref>{{cite magazine|title= Night Watchmen of the Skies|magazine= Popular Science|url= https://books.google.com/books?id=hCcDAAAAMBAJ&pg=PA56|date= December 1941|publisher= Bonnier Corporation|page= 56|access-date= 11 February 2021|archive-date= 7 October 2024|archive-url= https://web.archive.org/web/20241007062141/https://books.google.com/books?id=hCcDAAAAMBAJ&pg=PA56#v=onepage&q&f=false|url-status= live}}</ref> Also, in late 1941 ''[[Popular Mechanics]]'' had an article in which a U.S. scientist speculated about the British early warning system on the English east coast and came close to what it was and how it worked.<ref name="Popular Mechanics-1941">{{cite magazine|title=Odd-shaped Boats Rescue British Engineers|magazine= Popular Mechanics|url= https://archive.org/details/bub_gb_mtkDAAAAMBAJ/page/n67|date= September 1941|publisher= Hearst Magazines|page= 26}}</ref> Watson-Watt was sent to the U.S. in 1941 to advise on air defense after Japan's [[attack on Pearl Harbor]].<ref>{{cite news|title=Scotland's little-known WWII hero who helped beat the Luftwaffe with invention of radar set to be immortalised in film|url=http://www.dailyrecord.co.uk/news/real-life/scotlands-little-known-wwii-hero-who-3882904|newspaper=Daily Record|date=16 February 2017|access-date=16 February 2017|archive-date=17 February 2017|archive-url=https://web.archive.org/web/20170217064126/http://www.dailyrecord.co.uk/news/real-life/scotlands-little-known-wwii-hero-who-3882904|url-status=live}}</ref> [[Alfred Lee Loomis]] organized the secret [[MIT Radiation Laboratory]] at [[Massachusetts Institute of Technology]], Cambridge, Massachusetts which developed microwave radar technology in the years 1941–45. Later, in 1943, Page greatly improved radar with the [[Monopulse radar|monopulse technique]] that was used for many years in most radar applications.<ref>{{cite web | last=Goebel | first=Greg | title=The Wizard War: WW2 & The Origins of Radar | url=https://vc.airvectors.net/ttwiz_01.html | date=1 January 2007 | access-date=24 March 2007 | archive-date=2024-07-12 | archive-url=https://web.archive.org/web/20240712174051/https://vc.airvectors.net/ttwiz_01.html | url-status=live}}</ref>

The war precipitated research to find better resolution, more portability, and more features for radar, including small, lightweight sets to equip [[night fighter]]s ([[aircraft interception radar]]) and [[maritime patrol aircraft]] ([[air-to-surface-vessel radar]]), and complementary navigation systems like [[Oboe (navigation)|Oboe]] used by the [[Pathfinder (RAF)|RAF's Pathfinder]].