Theory of supervirtual refraction interferometry

Handle URI:
http://hdl.handle.net/10754/555748
Title:
Theory of supervirtual refraction interferometry
Authors:
Bharadwaj, Pawan; Schuster, Gerard T. ( 0000-0001-7532-1587 ) ; Mallinson, Ian; Dai, Wei
Abstract:
Inverting for the subsurface velocity distribution by refraction traveltime tomography is a well-accepted imaging method by both the exploration and earthquake seismology communities. A significant drawback, however, is that the recorded traces become noisier with increasing offset from the source position, and so accurate picking of traveltimes in far-offset traces is often prevented. To enhance the signal-to-noise ratio (SNR) of the far-offset traces, we present the theory of supervirtual refraction interferometry where the SNR of far-offset head-wave arrivals can be theoretically increased by a factor proportional to; here, N is the number of receiver or source positions associated with the recording and generation of the head-wave arrival. There are two steps to this methodology: correlation and summation of the data to generate traces with virtual head-wave arrivals, followed by the convolution of the data with the virtual traces to create traces with supervirtual head-wave arrivals. This method is valid for any medium that generates head-wave arrivals recorded by the geophones. Results with both synthetic traces and field data demonstrate the feasibility of this method. There are at least four significant benefits of supervirtual interferometry: (1) an enhanced SNR of far-offset traces so the first-arrival traveltimes of the noisy far-offset traces can be more reliably picked to extend the useful aperture of the data, (2) the SNR of head waves in a trace that arrive later than the first arrival can be enhanced for accurate traveltime picking and subsequent inversion by later-arrival traveltime tomography, (3) common receiver-pair gathers can be analysed to detect the presence of diving waves in the first arrivals, which can be used to assess the nature of the refracting boundary, and (4) the source statics term is eliminated in the correlation operations so that the timing of the virtual traces is independent of the source excitation time. This suggests the possibility of applying this method to earthquake data recorded by receivers that are inline with the refraction paths and source locations. © 2011 The Authors Geophysical Journal International © 2011 RAS.
KAUST Department:
Physical Sciences and Engineering (PSE) Division
Citation:
Theory of supervirtual refraction interferometry 2012, 188 (1):263 Geophysical Journal International
Publisher:
Oxford University Press (OUP)
Journal:
Geophysical Journal International
Issue Date:
Jan-2012
DOI:
10.1111/j.1365-246X.2011.05253.x
Type:
Article
ISSN:
0956540X
Additional Links:
http://gji.oxfordjournals.org/cgi/doi/10.1111/j.1365-246X.2011.05253.x
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Physical Sciences and Engineering (PSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorBharadwaj, Pawanen
dc.contributor.authorSchuster, Gerard T.en
dc.contributor.authorMallinson, Ianen
dc.contributor.authorDai, Weien
dc.date.accessioned2015-05-26T07:06:08Zen
dc.date.available2015-05-26T07:06:08Zen
dc.date.issued2012-01en
dc.identifier.citationTheory of supervirtual refraction interferometry 2012, 188 (1):263 Geophysical Journal Internationalen
dc.identifier.issn0956540Xen
dc.identifier.doi10.1111/j.1365-246X.2011.05253.xen
dc.identifier.urihttp://hdl.handle.net/10754/555748en
dc.description.abstractInverting for the subsurface velocity distribution by refraction traveltime tomography is a well-accepted imaging method by both the exploration and earthquake seismology communities. A significant drawback, however, is that the recorded traces become noisier with increasing offset from the source position, and so accurate picking of traveltimes in far-offset traces is often prevented. To enhance the signal-to-noise ratio (SNR) of the far-offset traces, we present the theory of supervirtual refraction interferometry where the SNR of far-offset head-wave arrivals can be theoretically increased by a factor proportional to; here, N is the number of receiver or source positions associated with the recording and generation of the head-wave arrival. There are two steps to this methodology: correlation and summation of the data to generate traces with virtual head-wave arrivals, followed by the convolution of the data with the virtual traces to create traces with supervirtual head-wave arrivals. This method is valid for any medium that generates head-wave arrivals recorded by the geophones. Results with both synthetic traces and field data demonstrate the feasibility of this method. There are at least four significant benefits of supervirtual interferometry: (1) an enhanced SNR of far-offset traces so the first-arrival traveltimes of the noisy far-offset traces can be more reliably picked to extend the useful aperture of the data, (2) the SNR of head waves in a trace that arrive later than the first arrival can be enhanced for accurate traveltime picking and subsequent inversion by later-arrival traveltime tomography, (3) common receiver-pair gathers can be analysed to detect the presence of diving waves in the first arrivals, which can be used to assess the nature of the refracting boundary, and (4) the source statics term is eliminated in the correlation operations so that the timing of the virtual traces is independent of the source excitation time. This suggests the possibility of applying this method to earthquake data recorded by receivers that are inline with the refraction paths and source locations. © 2011 The Authors Geophysical Journal International © 2011 RAS.en
dc.publisherOxford University Press (OUP)en
dc.relation.urlhttp://gji.oxfordjournals.org/cgi/doi/10.1111/j.1365-246X.2011.05253.xen
dc.rightsArchived with thanks to Geophysical Journal International © The Authors Geophysical Journal International © 2011 RASen
dc.subjectInterferometryen
dc.subjectInterface wavesen
dc.titleTheory of supervirtual refraction interferometryen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalGeophysical Journal Internationalen
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionIndian School of Mines, Dhanbad, Indiaen
kaust.authorSchuster, Gerard T.en
kaust.authorDai, Weien
kaust.authorBharadwaj, Pawanen
kaust.authorMallinson, Ianen
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