A Global Survey of ELF/VLF Radio Noise

Abstract

Award #: N00014-92-J-1576 and N00014-01-1-0543 LONG-TERM GOALThe specific long-term goal of this project is to provide the Navy with greatly improved information about the characteristics of both natural and man-made radio noise and signals in the ELF/VLF bands (frequencies in the range 10 Hz to 32 kHz), with the object of improving the Navy's ELF/VLF radio communications. SCIENTIFIC OBJECTIVESThe project has two related scientific objectives. The first objective is to improve knowledge of the sources of radio noise in the ELF/VLF band; the second is to improve knowledge of the propagation of ELF/VLF radio noise and man-made signals in the earth's environment, i.e., in the earth-ionosphere waveguide, in the magnetosphere, in the sea, and in the earth's crust.

Schumann resonances: Interpretation of local diurnal intensity modulations

“…Polk [1969] suggested using the cumulative intensity of three SR modes as a technique to reduce the source proximity effect and to estimate the current source intensity. An alternative method is to measure the ELF signal at the intermediate frequency, 10 Hz, i.e., between the first and second modes [Fraser-Smith et al, 1988]. Another approach, following Nickolaenko's [1997] suggestion, is placing the receiver at the North or South poles, which remain approximately equidistant from the main thunderstorm centers during the day.…”

Comment on “Natural magnetic disturbance fields, not precursors, preceding the Loma Prieta earthquake” by Wallace H. Campbell

“…Since our Electrical Engineering Department is heavily research oriented, we do not just buy and operate electronic measurement equipment but we have the additional capability to design and build innovative versions of such equipment, in addition to operating it, and some of our Stanford‐designed and ‐built equipment has been operating (without amplifier problems) for many years at some of the most inhospitable places on Earth [e.g., Fraser‐Smith et al , 1988, 1991]. Dating back to the International Geophysical Year (1957–1958), it has been the practice of researchers in our Department to incorporate what we refer to as calibration, or “CAL,” signals in the design of our measurement systems.…”

A Clustering Poisson model for characterizing the interarrival times of sferics

“…[9] The data used for the analysis are from the Stanford ELF/VLF Radio Noise Survey [Fraser-Smith and Helliwell, 1985;Fraser-Smith et al, 1988]. During the years 1985 -1986, a noise survey system of eight ELF/VLF (10 Hz -32 kHz) radio noise measurement stations (or radiometers) was installed at a variety of high-latitude and midlatitude sites, in an effort to fill large gaps in the information available on radio noise in the ELF/VLF frequency range.…”