Detection of VLF and ELF long path signals radiated from heated and modulated ionosphere current systems

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1985

OSTI ID:5880993

Lunnen, Jr, R J

This thesis describes the theoretical and experimental evidence of verified detection of very low frequency (VLF) and extremely low frequency (ELF) long-path signals radiated from a heated and modulated dynamo current system at mid-latitudes. A general background of the ionosphere current systems and prior research in VLF/ELF communications is followed by a complete description of the receiving subsystem. The on/off method of ionospheric heating with synchronous detection is the primary experimental technique. Phase reversal of the heating modulation envelope to create four-bit messages with synchronous averaging of the detected message is explained. A laboratory receiver subsystem calibration enables receiver system voltages to be related to the magnitude of the earth's horizontal magnetic field component at the receiving loop antenna. The laboratory calibration found a -20 dB threshold, below background noise level for detection of on/off type signals. This detection threshold was extended to -46.91 dB when 256 sample synchronous averaging was applied to four bit message data.

• Research Organization: Pennsylvania State Univ., University Park (USA)
• OSTI ID: 5880993
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CURRENTS
DETECTION
EARTH ATMOSPHERE
ELECTRIC CURRENTS
ELECTROMAGNETIC RADIATION
HEATING
IONOSPHERE
LONG WAVE RADIATION
PLANETARY IONOSPHERES
RADIATIONS
RADIOWAVE RADIATION