Patent ID: 6704245
Filing Date: 2004-03-09
Classification: G01V

Abstract:
A method of prospecting or monitoring of an underground formation by elastic waves, comprising:emitting in the ground elementary sequences formed by coding of a signal by pseudo-random sequences, receiving and recording the signals reflected by subsoil discontinuities in response to the emitted signals, and processing the recorded signals by correlation with signals formed from the emitted signals; and wherein the signals are emitted simultaneously by seismic sources each controlled by a signal of an elementary sequence of a length at least equal to a product of a number of seismic sources vibrating simultaneously by a listening time, a respective contribution of each one of the seismic sources being separated by correlating the received and recorded signals by signals constructed from the elementary sequence, extended with parts of a length at least equal to the listening time of the elementary sequence, obtained by circular permutation.