Accession Number:

AD0601427

Title:

THE REALIZATION OF ACTIVE SEISMIC SYSTEMS AND THEIR PRACTICAL APPLICATIONS,

Descriptive Note:

Corporate Author:

ARMY ELECTRONICS LABS FORT MONMOUTH NJ

Personal Author(s):

Report Date:

1964-04-01

Pagination or Media Count:

105.0

Abstract:

Design and experimental performance data are given of portable tuned seismic transducers for the transmission and reception of seismic signals on the weathered layer of the earth. These transducers are the elastic analogue of quarter wave radio antennas. They are designed for operation with conventional loudspeaker or microphone amplifiers. Experimental models of these transducers for nominal 10-watt drive power at 80 1.5 cps are the basic components in active seismic systems for communication, surveillance, and seismic exploration described here in detail. Seismic transmitters and receivers employing electrical- and seismic-feedback circuits are shown. Construction and operation of phased transducer-transmitter array circuits for the launching of directional seismic waves are described. Seismic signaling and measurement methods employing CW and amplitude, frequency, and phase modulation are described. The results of various experiments with these systems on lake ice and on soil in partially wooded terrain are given in the form of experimental data on communication ranges, power levels, signal-propagation velocities, and signal attenuation in ice and in the weathered layer of the earth relevant environmental factors are discussed and their influence on the propagation characteristics of seismic signals are shown. Author

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE