COMMITTEE \CTIVITIES 



21 



involved in correcting existing errors in fire control 

 radars, due to refractive effects. 



The fourth conference on propagation was held 

 in Washington in May 1945. This conference was 

 the largest and most comprehensive yet held and 

 was attended by 230 representatives of about 59 

 separate agencies of the Allied Nations. A report of 

 this conference was published as usual by the 

 CUDWR WPG and distributed through authorized 

 channels. A great ileal of important data was pre- 

 sented at this conference, including showing of a 

 motion picture produced in Britain which presented 

 in effective form much information on nonstandard 

 propagation, particularly propagation in ducts of 

 stratified air layers. Another short motion picture 

 prepared in Canada was presented in which radar 

 echoes from snowstorms were shown on an acceler- 

 ated time scale. Progress of such storms was readily 

 followed by radar observation, and the importance 

 of microwave propagation for this and similar 

 applications was made apparent. 



At the close of the conference the chairman 

 announced that a contract had been negotiated with 

 the Jam Handy Organization for production of a 

 motion picture to present pictorially the uses of 

 propagation data by the armed forces. 



With the collapse of the enemy in Europe, little 

 shifting of the Committee's program was required. 

 The Committee was formed too late in the war to be 

 of major help in the European theater so from the 

 start the efforts were aimed at the solution of propa- 

 gation problems of the war in the Pacific the- 

 ater. 



A meeting late in June 1945 considered advances 

 in theoretical methods of attacking the propagation 

 problem and agreed on certain standard symbols 

 for representing the quantities involved, to avoid 

 confusion between investigating agencies. 



Two additional contracts were arranged during 

 June, the first with the University of Texas for the 

 measurement of variations in angle of arrival of 

 microwave radiation under varying meteorological 

 conditions. This question has a very direct bearing 

 on the troublesome question of improving accuracy 

 of radar controlled gunfire, which played such an 

 important part in defense against Japanese suicide 

 plane attacks. 



The second contract was negotiated with the 

 Humble Oil Company on July 2, 1945, for the 

 manufacture of a number of field strength measur- 

 ing equipments which were required by various 



Service agencies of the I'nited States and Allied 

 nations. 



A particularly important meeting of the Committee 

 took place on July 13 in Washington. This meeting 

 was attended by several representatives of the 

 Allied Nations, including Professor D. R. Hartree, 

 J. M. C. Scott, and Lt. Comdr. F. L. Westwater from 

 England, and Drs. Kwei and Hsu from China. The 

 progress of the theoretical attack on wave propaga- 

 tion through a nonhomogeneous atmosphere was 

 thoroughly discussed by Prof. Hartree and Dr. C. L. 

 Pekeris of the Analysis Section of CUDWR WPG. 



Dr. A. T. Waterman of the Office of Field Service 

 reported on work being done in the Southwest 

 Pacific by D. E. Kerr. In the investigation of the diffi- 

 culties of operation of the MEW radar on Saipan he 

 confirmed the existence of a low-level evaporation 

 duct discovered by Dr. Anderson and Dr. Stephenson 

 in that area. Elevated ducts, the presence of which 

 had been suspected by Dr. Anderson from analyses of 

 radiosonde data, were definitely determined to exist 

 at heights ranging from 1,000 to 2,700 ft, as a result 

 of Kerr's investigations. 



Dr. Waterman also described a survey of Service 

 interest in scientific developments conducted in the 

 entire area commanded by General Mac Arthur, in 

 which a number of ways were found for OSRD to 

 assist the Army Air and Ground Forces. The Pacific 

 Branch of OSRD was organized so as to furnish a 

 consulting staff under a director, a pool of scientists 

 available for emergency field work, and a laboratory 

 for solution of emergency field problems. This work 

 was to be under directorship of Dr. K. T. Compton, 

 and it seemed very desirable to have a representative 

 in close touch with this OSRD unit in the field. 



Dr. Anderson stressed the importance of conduct- 

 ing additional research in the Southwest Pacific area, 

 and the need for informing the Services in that 

 theater more fully of the operational advantages to 

 be gained directly from such research. He went on 

 to report progress in development and production 

 of the equipment developed under the State College 

 of Washington contract for making atmospheric 

 soundings. 



Lt. Comdr. Westwater reported on the overland 

 propagation experiment going on at Suffield, Alberta, 

 which was not yet completed, and described the 

 meteorological conditions obtaining along the trans- 

 mission path. These were of the type producing 

 variations in the vertical angle of arrival of micro- 

 wave radiation transmitted at angles near the hori- 



