Pseudo-random scanning signal generation method of vibrator

Abstract

The present invention is a method for generating pseudo-random scanning signals of seismic acquisition vibrators in geophysical exploration. The Gold sequence code is generated according to the length of pseudo-random scanning signals of Num groups of vibrators to be generated, and the target amplitude spectrum is obtained. The cross-correlation and auto-correlation of the amplitude spectrum shaping signals are windowed to obtain the suppressed Num group reconstructed signals, and the maximum cross-correlation between each Num group of high-cut filter signals at the same time point is divided by the signal of each group The zero-time autocorrelation minimum value of the Num group of high-cut filter signals is obtained from the maximum relative cross-correlation value; iterative modification generates the final Num group of vibrator pseudo-random scanning signals, and the present invention can make the cross-correlation effect between each group of pseudo-random signals Weak, so as to suppress the interference of adjacent shots in the process of efficient acquisition, improve the separation quality of shot records, and the instantaneous frequency energy does not change monotonously with time, which can greatly reduce the risk of resonance caused by surrounding buildings during the construction of vibroseis.

Description

technical field [0001] The invention relates to a vibrator technology for seismic acquisition in geophysical prospecting, and relates to a method for generating pseudo-random scanning signals of a vibrator. Background technique [0002] Vibroseis technology is to use geophones to receive seismic waves excited by vibroseis in land seismic exploration to obtain underground structure information. Compared with explosive vibrators, vibrators have many advantages, such as safety, environmental protection, reusability, known and controllable excitation signals, etc., so they are more and more used in land seismic exploration. [0003] The conventional linear scanning signal is still the most widely used scanning method in vibroseis exploration. The linear scanning signal has many advantages, such as the average energy distribution, the energy occupied by the unit frequency is the same, and there is no frequency filtering effect on the signal components within the scanning frequen...

AI Technical Summary

Problems solved by technology

When the conventional linear scanning signal is used as the source signal for excitation, the related shot set records obtained by cross-correlation between the scanning signal and the vibration signal will have strong adjacent shot interference, so it is impossible to conduct on-site quality control on it, and the follow-up Higher requirements are put forward for the suppression of adjacent shot interference in seismic data processing

However, using the above-mentioned method of directly using m-sequences to generate pseudo-random vibroseis scanning signals, it is also impossible to generate several groups of scanning sequences with weak correlation characteristics, so it is still unable to directly suppress the interference of adjacent shots caused by high-efficiency acquisition

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