A multi-impulse source for shallow seismics

A broad frequency band of a seismic signal may be generated by a high frequency vibrator, a shotgun or some kind of a weight drop source with a small mass. However, a small mass generates only low signal amplitudes, so high fold stacking is necessary. A multi-impulse source generating many impulses during the recording time could overcome this need for high fold stacking. An example of a random multi-impulse source in combination with a special recording system is the Mini-Socie (Barbier et al., 1976). More recently a swept impact seismic technique (SIST) using standard enginering seismographs was presented by Park et al. (1996). Furthermore there are several relatively cheap apparatus or components commercially available which can be adapted as multi-impulse sources. This situation is encouraging to again investigate the performance of a multi-impulse source in combination with a standard engineering seismograph.