• journal_title：Geophysics
• Contributor：David A. Okaya ; Craig M. Jarchow
• Publisher：Society of Exploration Geophysicists
• Date：1989-
• Format：text/html
• Language：en
• Identifier：10.1190/1.1442682
• journal_abbrev：Geophysics
• issn：0016-8033
• volume：54
• issue：5
• firstpage：555
• section：Articles

Lower crustal seismic reflections can be extracted from shallow crustal seismic profiles through the application of extended correlation to uncorrelated Vibroseis seismic data. 'Fixed-bandwidth' extended correlation shortens the correlation operator before crosscorrelation, producing reflections over an increased correlation time range, all with lowered bandwidth. 'Self-truncating' extended correlation preserves the full bandwidth in the original seismic reflection times but loses bandwidth in a predictable manner at the additional (later) arrival times. Correlation wavelet shape and extra correlation time are directly related and can be calculated for specific acquisition parameters. Precorrelation tapering is necessary to avoid undue wavelet distortion at extended correlation times. Seismic data collected in the Basin and Range province illustrate the application of the method; the results are verified with conventional correlations of long sweep records and with impulsive source data.