Propagation Path Effects for Rayleigh and Love Waves
Seismic surface waves are usually composed of overlapping wave trains representing multi-path propagation. A first task in the analysis of such waves is to identify and separate the various component wave trains so that each can be analyzed separately. Phase-matched filters are a class of linear fil...
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ftdtic:ADA134936 2023-05-15T16:48:32+02:00 Propagation Path Effects for Rayleigh and Love Waves Herrin, E Goforth, T SOUTHERN METHODIST UNIV DALLAS TX DALLAS GEOPHYSICAL LAB 1978-04 text/html http://www.dtic.mil/docs/citations/ADA134936 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA134936 en eng http://www.dtic.mil/docs/citations/ADA134936 Approved for public release; distribution is unlimited. DTIC AND NTIS Seismology Radiofrequency Wave Propagation *LINEAR FILTERING *MATCHED FILTERS *SEISMIC WAVES AZIMUTH EARTHQUAKES FOURIER ANALYSIS ICELAND MULTIPATH TRANSMISSION NORWEGIAN SEA NUCLEAR EXPLOSIONS PROPAGATION RAYLEIGH WAVES SIGNAL PROCESSING SURFACE WAVES *Phase matched filters *Love waves Text 1978 ftdtic 2016-02-24T13:11:22Z Seismic surface waves are usually composed of overlapping wave trains representing multi-path propagation. A first task in the analysis of such waves is to identify and separate the various component wave trains so that each can be analyzed separately. Phase-matched filters are a class of linear filters in which the Fourier phase of the filter is made equal to that of a given signal. The authors previously described an iterative technique which can be used to find a phase-matched filter for a particular component of a seismic signal. Application of the filters to digital records of Rayleigh waves allowed multiple arrivals to be identified and removed, and allowed recovery of the complex spectrum of the primary wave train along with its apparent group velocity dispersion curve. A comparable analysis of Love waves presents additional complications. Love waves are contaminated by both Love and Rayleigh multipathing and by primary off-axis Rayleigh energy. In the case of explosions, there is much less energy generated as Love waves than as Rayleigh waves. The applicability of phase-matched filtering to Love waves is demonstrated by its use on earthquakes occurring in the Norwegian Sea and near Iceland and on a nuclear explosion in Novaya Zemlya. Despite severe multipathing in two of the three events, the amplitude and phase of each of the primary Love waves were recovered without significant distortion. See also report dated May 1981, ADA101088 Text Iceland Norwegian Sea Novaya Zemlya Defense Technical Information Center: DTIC Technical Reports database Norwegian Sea |
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Defense Technical Information Center: DTIC Technical Reports database |
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ftdtic |
language |
English |
topic |
Seismology Radiofrequency Wave Propagation *LINEAR FILTERING *MATCHED FILTERS *SEISMIC WAVES AZIMUTH EARTHQUAKES FOURIER ANALYSIS ICELAND MULTIPATH TRANSMISSION NORWEGIAN SEA NUCLEAR EXPLOSIONS PROPAGATION RAYLEIGH WAVES SIGNAL PROCESSING SURFACE WAVES *Phase matched filters *Love waves |
spellingShingle |
Seismology Radiofrequency Wave Propagation *LINEAR FILTERING *MATCHED FILTERS *SEISMIC WAVES AZIMUTH EARTHQUAKES FOURIER ANALYSIS ICELAND MULTIPATH TRANSMISSION NORWEGIAN SEA NUCLEAR EXPLOSIONS PROPAGATION RAYLEIGH WAVES SIGNAL PROCESSING SURFACE WAVES *Phase matched filters *Love waves Herrin, E Goforth, T Propagation Path Effects for Rayleigh and Love Waves |
topic_facet |
Seismology Radiofrequency Wave Propagation *LINEAR FILTERING *MATCHED FILTERS *SEISMIC WAVES AZIMUTH EARTHQUAKES FOURIER ANALYSIS ICELAND MULTIPATH TRANSMISSION NORWEGIAN SEA NUCLEAR EXPLOSIONS PROPAGATION RAYLEIGH WAVES SIGNAL PROCESSING SURFACE WAVES *Phase matched filters *Love waves |
description |
Seismic surface waves are usually composed of overlapping wave trains representing multi-path propagation. A first task in the analysis of such waves is to identify and separate the various component wave trains so that each can be analyzed separately. Phase-matched filters are a class of linear filters in which the Fourier phase of the filter is made equal to that of a given signal. The authors previously described an iterative technique which can be used to find a phase-matched filter for a particular component of a seismic signal. Application of the filters to digital records of Rayleigh waves allowed multiple arrivals to be identified and removed, and allowed recovery of the complex spectrum of the primary wave train along with its apparent group velocity dispersion curve. A comparable analysis of Love waves presents additional complications. Love waves are contaminated by both Love and Rayleigh multipathing and by primary off-axis Rayleigh energy. In the case of explosions, there is much less energy generated as Love waves than as Rayleigh waves. The applicability of phase-matched filtering to Love waves is demonstrated by its use on earthquakes occurring in the Norwegian Sea and near Iceland and on a nuclear explosion in Novaya Zemlya. Despite severe multipathing in two of the three events, the amplitude and phase of each of the primary Love waves were recovered without significant distortion. See also report dated May 1981, ADA101088 |
author2 |
SOUTHERN METHODIST UNIV DALLAS TX DALLAS GEOPHYSICAL LAB |
format |
Text |
author |
Herrin, E Goforth, T |
author_facet |
Herrin, E Goforth, T |
author_sort |
Herrin, E |
title |
Propagation Path Effects for Rayleigh and Love Waves |
title_short |
Propagation Path Effects for Rayleigh and Love Waves |
title_full |
Propagation Path Effects for Rayleigh and Love Waves |
title_fullStr |
Propagation Path Effects for Rayleigh and Love Waves |
title_full_unstemmed |
Propagation Path Effects for Rayleigh and Love Waves |
title_sort |
propagation path effects for rayleigh and love waves |
publishDate |
1978 |
url |
http://www.dtic.mil/docs/citations/ADA134936 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA134936 |
geographic |
Norwegian Sea |
geographic_facet |
Norwegian Sea |
genre |
Iceland Norwegian Sea Novaya Zemlya |
genre_facet |
Iceland Norwegian Sea Novaya Zemlya |
op_source |
DTIC AND NTIS |
op_relation |
http://www.dtic.mil/docs/citations/ADA134936 |
op_rights |
Approved for public release; distribution is unlimited. |
_version_ |
1766038622384947200 |