Accession Number : AD0910973
Title : Submarine Communication at ULF Frequencies. I. A Program of Investigation.
Descriptive Note : Semi-annual technical rept. Mar-Aug 72,
Corporate Author : PHYSICAL DYNAMICS INC DETROIT MI
Personal Author(s) : Podney, Walter
Report Date : SEP 1972
Pagination or Media Count : 89
Abstract : Electromagnetic energy in the ultra-low-frequency (ULF) spectral range (0.001 Hz to 5 Hz) penetrates sea water to depths of 250 meters or more before being appreciably absorbed. Because of the transparency of sea water to electromagnetic energy in the ULF band and the existence of global propagation paths at ULF frequencies, ULF carrier frequencies could provide a useful means of transmitting information to deeply submerged submarines. Information transfer at ULF carrier frequencies is limited to rates of about 1 bit/sec, so that communication with submarines using ULF carrier frequencies is suited to fulfilling an alerting or command and control function. Although ULF carrier frequencies afford a promising means of transmitting information to deeply submerged submarines, the concept of submarine communication at ULF frequencies is beset with fundamental uncertainties. Generation of signals at frequencies in the ULF band has yet to be demonstrated. Dispersion and absorption along global propagation paths have not been definitely assessed. And reception of signals on sea-based platforms has not been examined. Observations of naturally occurring signals in the ULF band, known historically as geomagnetic micropulsations, indicate that signal generation and propagation are possible within the near-Earth plasma. This report delineates and examines technical problems associated with signal generation, propagation, and reception from the point-of-view of submarine communication at ULF frequencies.
Descriptors : *UNDERWATER COMMUNICATIONS, *ULTRALOW FREQUENCY, DEEP SUBMERGENCE, PROPAGATION, OCEAN SURVEILLANCE, MAGNETOSPHERE, SEA WATER, DATA TRANSMISSION SYSTEMS, INTERACTIONS, COILS, ELECTRIC WIRE, THERMAL CONDUCTIVITY, DIPOLE MOMENTS, OSCILLATION, PLASMAS(PHYSICS), IONOSPHERIC PROPAGATION, GEOMAGNETISM, WAVE PROPAGATION.
Subject Categories : Submarine Engineering
Command, Control and Communications Systems
Distribution Statement : APPROVED FOR PUBLIC RELEASE