LARGE APERTURE SEISMIC ARRAYS
Abstract
The report describes three topics considered during the second quarter of Contract AF 19(628)-5981. Three topics reported on are: The estimation of the spectra of transient signals with additive noise; the theoretical aspects of clustering seismometers in a large aperture seismic array; the results of tests of a revised automatic pP phase detection technique. A method has been devised to estimate the energy density spectra of transient events in such a way that the variance of the spectral estimates produced by additive noise is minimized. The study of clusters shows: Dependence of array S/N performance on cluster spacing; a way in which to determine the amount of clustering possible without S/N degradation depending on noise conditions at the receiving site. Tests with the revised automatic pP detector have shown 100% correct results with surface focus events (6), 83% correct results for earthquakes (12), with the remaining earthquakes producing anomalies.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1967
- Accession Number
- AD0649681