Accession Number : ADA293572

Title :   Statistical Discrimination Studies for Nuclear Test Verification.

Descriptive Note : Final rept. 1 Jul 91-31 Dec 94,

Corporate Author : CALIFORNIA UNIV DAVIS INTERCOLLEGE DIV OF STATISTICS

Personal Author(s) : Shumway, Robert H. ; McQuarrie, Allan D.

PDF Url : ADA293572

Report Date : 31 DEC 1994

Pagination or Media Count : 56

Abstract : Robust statistical approaches to the problem of discriminating between regional earthquakes and explosions are developed. We compare linear discriminant analysis using descriptive features like amplitude and spectral ratios with signal discrimination techniques using the original signal waveforms and spectral approximations to the log likelihood function. Robust information theoretic techniques are proposed and all methods are applied to 8 earthquakes and 8 mining explosions in Scandinavia and to an event from Novaya Zemlya of unknown origin. It is noted that signal discrimination approaches based on discrimination information and Renyi entropy perform better in the test sample than conventional methods based on spectral ratios involving the P and S phases. Two techniques for identifying the ripple-firing pattern for typical mining explosions are proposed and shown to work well on simulated data and on several Scandinavian earthquakes and explosions. We use both cepstral analysis in the frequency domain and a time domain method based on the autocorrelation and partial autocorrelation functions. The proposed approach strips off underlying smooth spectral and seasonal spectral components corresponding to the echo pattern induced by two simple ripple-fired models. For two mining explosions, a pattern is identified whereas for two earthquakes, no pattern is evident.

Descriptors :   *STATISTICAL ANALYSIS, *NUCLEAR EXPLOSION DETECTION, *SEISMIC DISCRIMINATION, *EARTHQUAKES, COMPUTERIZED SIMULATION, LINEAR SYSTEMS, RATIOS, VERIFICATION, WAVEFORMS, EXPLOSIONS, AUTOCORRELATION, NUCLEAR EXPLOSION TESTING, MINING ENGINEERING, PHASE, SPECTRA, ECHOES, APPROXIMATION(MATHEMATICS), SIGNALS, PATTERNS, INFORMATION THEORY, TIME DOMAIN, FREQUENCY DOMAIN, FUNCTIONS(MATHEMATICS), DISCRIMINATE ANALYSIS, ENTROPY.

Subject Categories : Seismology
      Statistics and Probability
      Nuclear Warfare

Distribution Statement : APPROVED FOR PUBLIC RELEASE