Vibrator signals

5. Refraction Surveys

“…Ketelsen et al (1983) and Brötz et al (1987) suggested the use of a two-sided recursive shaping filter to convert the vibroseis processed data to minimum phase, as shown in Figure 5-22. Farrell and Euwema (1984a) recommended that the dominant peak of the arrival on conventionally processed vibroseis data should be picked because it corresponds to the zero-phase Klauder wavelet, which is the sweep autocorrelation wavelet of the vibroseis source (Hoover et al, 1984). Alternative techniques to convert data to minimum phase include the decon-volution-based approaches described by Ristow and Jurczyk (1975) and Gibson and Larner (1984).…”

Wireless Geophone Networks for Land Seismic Data Acquisition: A Survey, Tutorial and Performance Evaluation

“…Energy produced by the explosive is transmitted as a seismic wave signal that radiates outward in all directions via the earth subsurface, and reflections are recorded at the receivers on the surface [17]. • Vibratory: Vibrators (vibroseis) are the most commonly used sources in land seismic exploration [18] due to some advantages it has over impulsive sources, such as limited frequency band, low-power source, longer energy emission time [19], less safety concerns, as well as better control of sweep repetition. A vibrator is a vehicle-mounted energy source that converts an electrical signal into high-pressure hydraulic flow to vibrate and control a heavy base plate held in contact with the ground by the weight of the vibrator vehicle and isolated by an air-bag suspension [19].…”

“…• Vibratory: Vibrators (vibroseis) are the most commonly used sources in land seismic exploration [18] due to some advantages it has over impulsive sources, such as limited frequency band, low-power source, longer energy emission time [19], less safety concerns, as well as better control of sweep repetition. A vibrator is a vehicle-mounted energy source that converts an electrical signal into high-pressure hydraulic flow to vibrate and control a heavy base plate held in contact with the ground by the weight of the vibrator vehicle and isolated by an air-bag suspension [19]. A reference sweep signal encoded in the vibrator electronics is sent into the ground through the vibrator plates for a given period of time known as the "sweep or shot time".…”

Βελτιστοι Αλγοριθμοι Κατεργασιας Γεωφυσικων Δεδομενων

“…Η τοποθέτηση των εκρηκτικών γίνεται μέ σα σε μια τρυπά, αρκετά βαθιά ώστε να βρίσκεται κάτω απο το στρώμα επιφάνειας, συνήθως σε βάθος 20-30 m. Μια τέτοια "κρου στική" πηγή παράγει σήματα πολύ μικρής χρονικής διάρκειας και μεγάλου'πλάτους. Περισσότερες λεπτομέρειες για την παραγωγή βασικών σεισμικών κυμάτων υπάρχουν στα [7], [8] , [9] , [10] , [11] "…”