ORIGIN AND ORGANIZATION 



grated global communications over vast areas of 

 unfavorable terrain and with thousands of mobile 

 units. 



Very early in the conflict it was realized that only 

 the British development and organized employment 

 of radar had permitted that country, with a numeric- 

 ally inferior air force, to defeat the Luftwaffe deci- 

 sively in the Battle of Britain, in which the German 

 High Command had hoped to destroy the Royal 

 Air Force and open the way for a successful invasion 

 of Great Britain. Early warning radar permitted the 

 British commanders to conserve their small resources 

 of men and materiel by sharply reducing air patrol- 

 ling, and by conducting interceptions with an exac- 

 titude which conserved men and aircraft flying hours 

 to the utmost. 



With the importance of radar thus established, its 

 use was rapidly expanded and extended into new 

 applications. To protect the extremely long sea 

 supply lines from crippling submarine attacks, radar 

 detection devices were developed expressly to detect 

 surfaced submarines as the only practicable means 

 of searching wide areas of ocean under varying 

 conditions. 



With the entry of the Japanese into the struggle, 

 the field of operations became truly global, and the 

 demands made on detection and communication 

 equipment became more severe in all respects. Rapid 

 improvement was made in the performance and 

 reliability of radio and radar equipment to meet 

 these increased demands. 



With these advances in design and manufacture 

 and the speedy accumulation of a large amount of 

 factual data on equipment performance in the field, 

 it soon became apparent that meteorological condi- 

 tions in the troposphere had very serious influence 

 on the operational efficiency of such apparatus. In 

 particular, it was noted that the reliable coverage 

 area of a given installation varied considerably with 

 weather conditions, with the result that confidence 

 in early warning radar and very high-frequency 

 communication links was reduced, and this loss of 

 confidence affected field operations seriously. It thus 

 became vitally necessary to investigate as rapidly 

 and completely as practicable the causes of such 

 variations, with a view to discovering ways of mini- 

 mizing reductions of coverage and reliability and to 

 improving the general overall performance.' 



The need for this investigation was communicated 

 from units in the field through regular liaison channels 

 to the National Defense Research Committee 



[NDRC] in the United States, and to the Depart- 

 ment of Scientific and Industrial Research in Great 

 Britain. Certain researches into the problem were 

 begun independently in the two countries. During 

 the course of the discussion perviously referred to 

 between Dr. Compton and Sir Edward Appleton, 

 the need for a body to coordinate these researches 

 was revealed. The magnitude and complexity of 

 the problem, occasioned by the extreme variations 

 in equipment, siting, terrain, and meteorology in 

 the various theaters of operations, made it essential 

 to divide the investigation so as to avoid gaps 

 or duplication of effort. This could be achieved 

 only by integrating research programs through a 

 coordinating body. 



Accordingly the radar mission under the chairman- 

 ship of Dr. Compton, upon its return to the United 

 States strongly recommended the formation of such 

 a body. 



12 ORGANIZATION 



A preliminary conference on propagation was held 

 July 1 and 2, 1943 at the Massachusetts Institute of 

 Technology, at which most of the interested United 

 States agencies were represented. This conference 

 was held under the chairmanship of Donald E. Kerr, 

 leader of the propagation group of the Radiation 

 Laboratory and was called specifically for the 

 following purposes: 



1 . To make those attending acquainted with each 

 other and with the work then in progress. 



2. To review and summarize the general status of 

 microwave propagation knowledge in the United 

 States. 



3. To compare general measurement techniques. 



4. To standardize terminology and methods of 

 presenting data. 



5. To formulate a program for future research and 

 recommend any necessary redistribution of emphasis. 



The general conclusion reached by this conference 

 was that the following subjects were of greatest 

 importance : 



1. Perfection of the technique of radar range 

 forecasting to a degree which would make it immedi- 

 ately useful to the services, even if this had to be 

 done in a preliminary form. 



2. Continuation of both theoretical and experi- 

 mental investigation of the mechanism by which the 

 properties of the atmosphere and earth affect micro- 



