Seismic prospecting method and device using simultaneous emission of seismic signals based on pseudo-random sequences

摘要

A seismic prospecting method and device is disclosed using simultaneous emission, by 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 are formed either from elementary sequences whose length is at least equal to the product of the number of seismic sources vibrating simultaneously by a listening time, or from the 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.