LARGE APERTURE SEISMIC ARRAYS
Quarterly technical rept. no. 2, Jun-Sep 1966
GENERAL ATRONICS CORP PHILADELPHIA PA
Pagination or Media Count:
The report describes three topics considered during the second quarter of Contract AF 19628-5981. 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 SN performance on cluster spacing a way in which to determine the amount of clustering possible without SN 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.