NDLI: Radio-Wave Propagation between World Wars I and II

Content Provider	IEEE Xplore Digital Library
Author	Attwood, S.S.
Copyright Year	1931
Abstract	The period between World Wars I and II, 1918 to 1941, is particularly noteworthy for the significant developments that led to a comprehensive understanding of the factors that control the propagation of radio waves through the atmosphere. In slightly over two decades it became possible to identify the basic physical mechanisms with the aid and correlation of theory and experiment, so that by the end of this period it was possible to prepare predictions of future propagation conditions covering a wide variety of frequencies, transmission paths, for day and night, and seasonal variations. During the entire period, numbers of scientists were working toward the calculation of field strengths of radio waves propagated by both the ground wave and the ionosphere. Watson's paper in 1918 initiated the ground wave calculations by considering the propagation over a perfectly conducting sphere. It was soon recognized that the ground could not be treated as perfectly conducting, and the theory of propagation for an imperfectly conducting ground was not produced in usable form until the 1937-1941 period. Watson's predictions for field strengths in the shadow zone proved to be much lower than experimental values. This led to increased interest in the ionosphere as a possible explanation. Effective work on ionospheric problems began in 1924 with the development of the Eccles-Larmor theory of electronic behavior. The effect of the earth's magnetic field extended this theory to include doubly refracting layers and ionospheric layer anistropy.
Starting Page	688
Ending Page	691
Page Count	4
File Size	1116051
File Format	PDF
ISSN	00968390
Volume Number	50
Issue Number	5
Language	English
Publisher	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Publisher Date	1962-05-01
Access Restriction	Subscribed
Rights Holder	The Institute of Radio Engineers, Inc. (IRE)
Subject Keyword	Frequency Atmosphere Ionosphere Earth Microwave propagation Surface waves Electromagnetic diffraction Radio control Radiofrequency identification Electrons
Content Type	Text
Resource Type	Article
Subject	Electrical and Electronic Engineering

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in