| 摘要 |
Seismic prospecting method and device using simultaneous emission, by several vibrators, of seismic signals obtained by phase modulating a periodic signal whose amplitudes and derivatives with respect to the amplitude time are equated to zero at the beginning and at the end of each period, by pseudo-random sequences. The seismic signals reflected by the subsoil discontinuities in response to the periodic signals emitted are picked up by receivers coupled with the formation and recorded in an acquisition and recording system. The seismic signals emitted are formed either from elementary sequences whose length is at least equal to the product of the number of seismic souces vibrating simultaneously by the listening time, or from this elementary sequence extended, before and after, with parts whose length is at least equal to the listening time, the reception and recording of the signals reflected by the subsoil discontinuities in response to the signals emitted, and the processing of the recorded signals. The respective contributions of the various seismic sources are isolated by correlating the signals received and recorded either by signals constructed from said elementary sequence extended, before and after, with parts whose length is at least equal to the listening time, obtained by circular permutation, or of said elementary sequence.
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