Infrasonic monitoring of UGTs and earthquakes for discrimination

Conference · Sat Aug 01 04:00:00 EDT 1992

OSTI ID:10167469

Whitaker, R W; Noel, S; Mutschlecner, J P; Davidson, M

Over the last several years, as part of Los Alamos verification activity, low frequency acoustics measurements have been made of underground nuclear tests (UGTs). The measurements have been made with arrays at St. George, Utah, and Los Alamos, New Mexico; both arrays operate continuously, and many earthquakes (EQs) have been recorded as well. The general frequency range is 0.1 to 10 Hz, in the infrasonic domain. In this domain the atmospheric signals are still longitudinal pressure waves. Propagation for frequencies around 1 hz is excellent with little excess attenuation over simple geometric spreading. Measured peak to peak pressure levels range from 0.1 to 60 {mu}bars, where one bar is normal atmospheric pressure. We employ standard array processing techniques (beamforming) to derive the usual outputs of correlation coefficient, trace velocity, duration, power spectrum, and azimuth for sequential windows of data. Undesired signals can be subtracted from the beam, and frequency filtering can be used to improve signal to noise in desired passbands.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 10167469
• Report Number(s): LA-UR--92-2473; CONF-9205166--3; ON: DE92018600
• Country of Publication: United States
• Language: English

Related Subjects

350300
45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
450300
98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL PROTECTION
ARRAY PROCESSORS
DISTANCE
EARTHQUAKES
HZ RANGE
MATHEMATICAL MODELS
MEASURING METHODS
MONITORING
NOISE
NUCLEAR EXPLOSION DETECTION
NUCLEAR EXPLOSIONS
SIGNAL CONDITIONING
UNDERGROUND EXPLOSIONS
VELOCITY
VERIFICATION