Investigation of the stimulation of ulf waves

Technical Report · Thu Nov 13 04:00:00 EST 1975

OSTI ID:7333749

Willis, J W; Davis, J R

Two methods of artificially stimulating ultra-low-frequency (ulf) waves in the ionosphere have been investigated experimentally. Radio-frequency heating of the ionospheric-dynamo-current region has been attempted by using a high-frequency transmitter and has been found to be ineffective. Pulse modulation of the U.S. Navy vlf transmitter at Cutler, Maine, has been explored as a means of stimulating geomagnetic micropulsations. In a month-long experiment the transmitter was square-wave modulated at frequencies of 0.2, 1, and 5 Hz, with a network of sensitive magnetometers employed as micropulsation detectors. Although the experimental results are not statistically conclusive, micropulsations occurred on several occasions at harmonics of the transmitter modulation frequency. It is likely that ulf waves may be stimulated by this means under magnetically quiet conditions immediately following geomagnetically active days. It is concluded that practical means of emitting ulf waves for global communications are prohibitively expensive by comparison to other alternatives in the extremely-low-frequency or higher bands. (GRA)

• Research Organization: Naval Research Lab., Washington, D.C. (USA)
• OSTI ID: 7333749
• Report Number(s): AD-A-018245; NRL-7925
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COMMUNICATIONS
COST
EARTH ATMOSPHERE
ELECTROMAGNETIC RADIATION
ENERGY-LEVEL TRANSITIONS
EXCITATION
FREQUENCY RANGE
GEOMAGNETIC FIELD
HEATING
HZ RANGE
INTERACTIONS
IONOSPHERE
MAGNETIC FIELDS
MAGNETOSPHERE
PULSATIONS
RADIATIONS
RADIOWAVE RADIATION
TRANSMISSION