Chapter 2 

 OBJECTIVES AND RESEARCH AGENCIES 



2.1 



DIRKCTIVi; AM) OBJKCT1VKS 



The original directive for the Committee on 

 Propagation was issued by Dr. James B. Conant, 

 NDRC Chairman, in November 1943 and read as 

 follows: 



It shall be the duty of the Propagation Committee of the 

 NDRC to organize and coordinate a program designed to 

 secure the answers to problems on propagation of importance 

 to the war effort. Its recommendations of contracts should be 

 transmitted to the NDRC through Divisions 13, 14, and 15, 

 and the supervision of the contracts remains with the Divisions 

 which transmit the recommendations to the NDRC. It shall 

 give consideration to the needs of Divisions 13, 14, and 15 

 within the field in which it is limited. Information secured 

 by this Committee and by corresponding sections of Divisions 

 13, 14, and 15 shall be made mutually available as desired by 

 the groups and may be used by the groups for the purpose of 

 carrying out their missions. It is further understood that one 

 of the duties of the Committee on Propagation is to assemble 

 and analyze, and make available to appropriate agencies, all 

 information in regard to propagation of importance to the 

 wa" effort. 



The directive was purposely made broad enough 

 to permit investigation in any direction promising 

 useful results. In view of this breadth, it was neces- 

 sary to establish a priority list of specific problems 

 for immediate attack. Proper choice of the problems 

 on this list was of great importance to the successful 

 accomplishment of the Committee's objectives and 

 accordingly was taken up at the first regular meeting, 

 held on October 13, 1943. During the course of this 

 meeting the specific functions of the Committee were 

 also defined, as follows: 



1. To coordinate the research then going forward 

 in the United States and to initiate any new work 

 necessary to round out the program. 



2. To review completely the existing data on 

 propagation, correlate it, put it into a form usable 

 in the Services, and disseminate it through author- 

 ized liaison channels being set up for the purpose. 



3. To cooperate with similar agencies in the United 

 Kingdom and other Allied nations for exchange of 

 information and coordination of research, with a 

 view to avoiding duplication of effort or of gaps in 

 the investigation. 



With the establishment of these specific functions, 

 two operational problems were selected as being of 

 the highest priority. These were the tracking of 



storms and estimation of their properties with radar 

 equipment and the prediction of range for all types 

 of radio equipment employing that part of the 

 electromagnetic spectrum above 30 mc. 



The additional problems of determining necessary 

 radar facilities, radar navigation along a shore line, 

 and siting of direction finder equipment, were dis- 

 cussed, but it was decided that these subjects were 

 either outside the province of the Committee or were 

 being adequately considered by other agencies. 



The following research problems were also agreed 

 upon : 



1. Propagation in nonhomogeneous media. 



a. Meteorology. (1) A thorough review of avail- 

 able instruments and methods for making 

 atmospheric soundings and initiation of a 

 program of manufacture of suitable types. 

 (2) Development of techniques for employ- 

 ing these instruments by means of sounding 

 balloons, aircraft, etc. (3) Determination of 

 the dielectric constant of the troposphere as 

 a function of height, at locations within the 

 United States or possessions where condi- 

 tions in strategically important war theaters 

 are reasonably well simulated. (4) Repetition 

 of operations of (3) in selected strategically 

 important regions or their meteorological 

 equivalent, to obtain sample refractive index 

 distributions. (5) Conduction of meteoro- 

 logical weather analysis concurrently with 

 functions under (3) and (4) . (6) Sponsorship 

 of further research into world-wide meteoro- 

 logical conditions, their diurnal and seasonal 

 variations, and their effect on propagation. 



b. Theoretical analysis of propagation. (1) Ex- 

 tension of analytical methods to permit bet- 

 ter physical understanding of the effects of 

 varying refractive index distribution. (2) 

 Preparation of working formulas for deter- 

 mining field strength and fading charac- 

 teristics. 



c. Establishment of experimental propagation 

 measuring circuits in locations where results 

 of (4) above make such experiments advis- 

 able, these experiments to be correlated with 

 simultaneous meteorological observation and 



