Regional small-event identification using seismic networks and arrays. Scientific report No. 1

Technical Report · Mon Jul 15 04:00:00 EDT 1996

OSTI ID:464213

Hedlin, M; Vernon, F; Minster, J B; Orcutt, J

We have been contracted by AFTAC to develop a small event discriminant that uses a time frequency expansion (sonogram) of seismic coda to discriminate ripple fired mining explosions from single explosions and earthquakes. The Automated Time Frequency Discriminant (ATFD) which we have developed uses a binary sonogram which is derived from the original, spectral, sonogram by the application of filters which replace the spectral information with a binary code which simply reflects local spectral highs and lows. We have found that the binary patterns which we extract from the coda of ripple-fired events are banded and thus distinct from those obtained from single explosions and earthquakes. The bands, which result from source finiteness, intershot delays or a combination of the two, are largely independent of time and of the recording component. The ATFD uses three statistical tests to measure the time and recording component independence and automatically recognize these bands. All of the raw discrimination parameters produced by these tests are merged into a single discriminant score with multivariate statistics.

• Research Organization: California Univ., San Diego, La Jolla, CA (United States). Inst. of Geophysics and Planetary Physics
• OSTI ID: 464213
• Report Number(s): AD-A--319766/2/XAB; CNN: Contract F19628-95-K-OO12
• Country of Publication: United States
• Language: English

Related Subjects

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
AUTOMATION
CHEMICAL EXPLOSIONS
NUCLEAR EXPLOSION DETECTION
REGIONAL ANALYSIS