Instrumentation and Measurement Techniques for the Detection of Extremely Low Frequency Electromagnetic Energy in the Sea

摘要

The need for oceanographic data relating to electromagnetic noise in the Extremely Low Frequency region of the spectrum prompted the Laboratory to design instrumentation capable of obtaining absolute ELF measurements of sea-generated noise. The instrumentation as installed in the Navy General Oceanographic Research Vessel, USNS GILLISS (AGOR-4), is described, and the measurement techniques are discussed. Results of a power spectrum analysis on some of the data from the October 1964 trip of the GILLISS are presented. Ultimately the analysis of all the data will result in quantitative ELF electromagnetic noise levels as a function of frequency, time of day, season, geographic location, and meteorological and oceanographic conditions. (Author)