HR: 0830h
AN: U31B-0016    [PDF]
TI: A Novel Piezoelectric-Cable Infrasound Sensor
AU: * Kern, F R
EM: kern@psicorp.com
AF: Physical Sciences, Inc., 20 New England Business Center, Andover, MA 01810-1077 United States
AU: Africk, S A
EM: safrick@att.net
AF: Physical Sciences, Inc., 20 New England Business Center, Andover, MA 01810-1077 United States
AU: Chaves, R G
EM: rgc@psicorp.com
AF: Physical Sciences, Inc., 20 New England Business Center, Andover, MA 01810-1077 United States
AU: Cataldi, P
EM: cataldi@psicorp.com
AF: Physical Sciences, Inc., 20 New England Business Center, Andover, MA 01810-1077 United States
AU: Hedlin, M A
EM: hedlin@ucsd.edu
AF: Laboratory for Atmospheric Acoustics, Chair Institute of Geophysics and Planetary Physics Scripps Institution of Oceanography University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0225 United StatesAU: Coon, C
EM: ccoon@epicenter.ucsd.edu
AF: Laboratory for Atmospheric Acoustics, Chair Institute of Geophysics and Planetary Physics Scripps Institution of Oceanography University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0225 United StatesAB: A novel infrasound sensor consisting of a long length of radially-poled commercially available piezoelectric polyvinylidene fluoride (PVDF) coaxial cable and a specially designed amplifier has been developed as a potential improved performance and lower cost replacement for microbarograph-based systems such as employed in the CTBT program. These cables are readily available and relatively inexpensive, supporting design of easily-replaced or expendable sensor elements. The purely electronic transduction mechanism provides uniform sensitivity to pressure along the sensor's length ("at lightspeed"). This automatically gives rise to continuous spatial averaging (i.e. array gain) of both signals and environmental pressure fields such as wind to provide noise reduction. Electronic transduction also allows for combination of signals from multiple sensors to enable signal processing options not possible with many other types of infrasound sensors. Prototype sensors of 30 and 100 m were installed several inches deep in trenches at UCSD's Pinon Flat Observatory in May 2003 and infrasonic data have been telemetered to UCSD in La Jolla continuously since then. The piezocable sensors have successfully detected acoustical events detected by the CTBT infrasound array and other diagnostic sensors at Pinon Flat with appropriate magnitude and good coherence. As anticipated, the longer sensors tend to be quieter than the shorter and appear to provide spatial filtering of higher acoustic frequencies. Two sensors placed at right angles appear to provide the potential to identify the direction of incoming signals within a 180 degree uncertainty. Work is continuing to further characterize the signal sensitivity and environmental noise of these sensors. This project has been carried out under a Small Business Innovation Research Contract from DTRA.
DE: 0394 Instruments and techniques
DE: 3394 Instruments and techniques
DE: 7294 Instruments and techniques
DE: 8494 Instruments and techniques
DE: 9805 Instruments useful in three or more fields
SC: U
MN: 2003 Fall Meeting