Summary of extremely low frequency (ELF) field strength measurements made in Connecticut during 1975
Article first published online: 7 DEC 2012
Copyright 1979 by the American Geophysical Union.
Volume 14, Issue 1, pages 103–108, January-February 1979
How to Cite
1979), Summary of extremely low frequency (ELF) field strength measurements made in Connecticut during 1975, Radio Sci., 14(1), 103–108, doi:10.1029/RS014i001p00103.(
- Issue published online: 7 DEC 2012
- Article first published online: 7 DEC 2012
- Manuscript Received: 13 JUN 1978
Both 42- and 76-Hz, horizontal, magnetic-field-strength measurements (amplitude and relative phase) were made in Connecticut during 1975. These measurements were taken to further investigate sunrise, daytime, sunset, nighttime, and seasonal extremely low frequency (ELF) propagation variations. The transmission source for these 1.6-Mm range measurements was the US Navy ELF Wisconsin Test Facility. It was determined from these measurements that (1) ELF nighttime propagation is much more variable than daytime propagation, (2) the “Halloween effect” was observed for the sixth consecutive year, and (3) phase velocity changes during pure nighttime propagation conditions occasionally appear to be greater than changes associated with the sunrise-sunset terminators crossing the transmitter or receiver locations.