14 



CHRONOLOGICAL RECORD 



Prof. Attwood was appointed Director of the Colum- 

 bia University Wave Propagation Group [CUDWR 

 WPG] which operated under contract OEMsr-1207, 

 to integrate, analyze, and disseminate reports of 

 research. This contract went into force on Novem- 

 ber 1, 1943. 



Dr. Burrows, Prof. Attwood, and D. E. Kerr flew to 

 England November 22, 1943, to confer with British 

 investigators and secure integration of the United 

 States and British programs. As a result of this visit, 

 a unified program of research was agreed upon, with 

 certain divisions of effort to prevent duplication of 

 particular phases of the work, and to insure covering 

 all practical aspects of the problem. The British 

 agreed to continue experiments on wavelengths of 

 9, 6, and 3 cm, with parallel measurements of 

 meteorological factors, and also to undertake 

 measurements at 1.25 cm when equipment became 

 available. The effects of hills and trees on the shorter 

 wavelengths was also to be studied. They were also 

 to continue theoretical investigations already under 

 way with special emphasis on use of the Manchester 

 University differential analyzer. 



It was agreed that American agencies would make 

 detailed measurements to determine the character- 

 istics of water vapor diffusion in a warm air mass 

 blowing over cold water, with accompanying radio 

 transmission tests at wavelengths of roughly 10 and 

 50 cm. A team of research workers was to be organ- 

 ized and equipped to make simultaneous propagation 

 and meteorological measurements at locations pro- 

 viding conditions similar to those encountered by 

 radar-using personnel of the armed forces. Tests on 

 1.25-cm waves were to be made along the eastern 

 coast of the United States as apparatus permitted, 

 to provide data on propagation conditions typical 

 of the eastern coast of a large continent. 



It was agreed also that Dr. John E. Freehafer of 

 MIT-RL would be sent to Britain in order to obtain 

 closer cooperation in theoretical attacks being made 

 on these problems. 



It was further agreed to make a study of atmos- 

 pheric absorption, particularly at 3-cm and shorter 

 wavelengths, and of absorption by rain, fog, dust, 

 and other such phenomena. The reflection coefficient 

 of the sea for radiation of 10-cm and possibly 3-cm 

 and shorter wavelengths was to be studied for graz- 

 ing angles less than 5 degrees, and the back-scatter- 

 ing effect was also to be investigated. Storm echoes 

 and their possible tactical uses were also to be 

 treated. In addition, the United States was to set up 



and maintain a group to compile, analyze, integrate, 

 and disseminate propagation information. 



It was jointly agreed to interchange samples of 

 meteorological instruments most useful for measure- 

 ments in connection with propagation studies. 



Upon return to the United States of this mission, 

 in January 1944, offices were occupied in the Empire 

 State Building, New York City, jointly with the 

 Wave Propagation Group of Columbia University 

 Division of Wir Research. 



On February 12, 1944, a meeting was held at 

 which liaison representatives from the armed forces 

 presented certain urgent Service requirements and 

 outlined experimental programs that the respective 

 branches were prepared to undertake in cooperation 

 with the Committee. 



One of the most urgent needs in the Services was 

 for a handbook and other instructional aids, prepared 

 in the simplest practicable form for the use of opera- 

 tional personnel with limited technical background. 

 It was proposed that the Columbia University Wave 

 Propagation Group, which had been set up in accord 

 with the program agreed on with the British, should 

 undertake the preparation of such aids to instruction. 



At a meeting held February 15, 1944, a statement 

 outlining the propagation problem was drawn up, 

 with proposals for Service cooperation in experiments 

 devised to provide solutions to the most urgent 

 aspects of the question. This statement set forth the 

 NDRC Committee's view that the problem of "non- 

 ionospheric propagation in a nonstandard atmos:- 

 phere" should be given highest priority, and it gave 

 details of experiments proposed or already under 

 way. Five specific experiments were outlined, in each 

 of which the assistance of the Services was required. 

 These were as follows: 



1. Organization and equipment of a complete 

 transportable field unit for conducting propagation 

 experiments, which could be sent to any region 

 considered likely to yield results useful in the opera- 

 tional theaters. This experiment would require con- 

 siderable apparatus and a team of trained research, 

 operational, and maintenance personnel. Dr. Paul 

 Anderson of the State College of Washington 

 provided a considerable amount of material on this 

 project. 



2. An over-water experiment along a path between 

 Cape Ann and Cape Cod was to be carried out by 

 MIT-RL, to obtain information on propagation 

 characteristics along the eastern coast of a continent. 

 These data would be applicable to similar regions in 



