OCEAN ELECTRONIC NAVIGATIONAL AIDS 55 



RADAR ' 



The basic principle of Radar is not a difficult one. In 1886 it was proved 

 that radio waves are reflected from solid objects. In 1904, a German engi- 

 neer was granted a patent in several countries on a proposed way of using 

 this property as an obstacle detector and a navigational aid for ships. A dis- 

 covery which led to the actual development of Radar was made in 1922 by 

 two scientists working at the Naval Aircraft Radio Laboratory, Anacostia, Md. 

 Testing plane-to-ground communications, they noticed that ships moving in 

 the Potomac River distorted the pattern of radio waves, causing a fluctuating 

 signal. From this discovery, development was pursued almost continually 

 after that until 1935, when Congress provided a $100,000 appropriation to the 

 Naval Research Laboratory for the development of Radar. A rather crude 

 Radar was tested successfully in 1937 aboard the U. S. S. Leary, and a greatly 

 improved one was given extensive sea trials on the U. S. S. New York in 1939. 

 Before that, experimental work conducted from the ground employed a 

 variety of ships and aircraft and the dirigible Akron. 



Probably no scientific or industrial development in the history of the 

 world has so expanded in all phases simultaneously, and on such a scale. 

 Research, development, production design, actual production, field trials, 

 training of thousands of operators and installers — all of these had to go on at 

 the same time, and they did. Most significant of all, the use of Radar 

 with the armies and the air forces in the field, and the ships at sea, was so 

 widespread that nearly every responsible commanding officer had to be edu- 

 cated to an appreciation of the capabilities and the limitations of the new 

 equipment through the trial and error of combat operations. Further, they 

 had to communicate the experience and knowledge thus gained to all other 

 field commanders. All this was made more difficult by the necessity of 

 maintaining the strict secrecy which must surround a new and important 

 development. 



The development of Radar moved so rapidly through the last years before 

 the war and the early years of the war itself that only the Radar specialist 

 had any real knowledge of its behavior and its capabilities. Yet the immedi- 

 ate demands of war made it necessary to expand suddenly and tremendously 

 in all directions at once. 



During the war only the armed forces employed Radar. For this reason, 

 and because of its close connection with the maritime industry, the Coast 

 Guard prior to the end of hostilities commenced a study of Radar for peace- 

 time employment. 



As the war progressed and the existence of Radar became known publicly, 

 the Coast Guard was approached by commercial ship operators with requests 

 as to how Radar could be used for commercial navigation. While the infor- 

 mation could not be released under wartime restrictions, the need for such 

 a study, was realized and an extensive program to collect data was under- 

 taken. The United States Coast Guard cutter Mackinaw was radar- 

 equipped especially for study of conditions on the Great Lakes. Additional 

 ships and planes were equipped and specialized personnel assigned for a 

 study of conditions on the Grand Banks during the 1945 Ice Patrol. Various 

 harbor craft were equipped and studies on the employment of Radar in 

 harbors were made. To coordinate activities a Radar study group whose 

 sole purpose was to disseminate existing information and accumulate new 

 data was established at Coast Guard Headquarters in the early part of 1945. 

 These activities culminated finally in the public release of Radar information 

 simulanteously with the releases on Loran and the publication of advisory 

 specifications for Merchant Marine Radar equipment. 



3 The word Radar was coined by a U. S. Navy oflScer and ofllcially adopted by the 

 U. S. Navy in 1941. 



