METHOD FOR ATTENUATING HARMONIC NOISE IN VIBROSEIS BY MEANS OF REFERENCED TIME-VARIANT FILTERING

摘要

The invention relates to a method for improving the quality of vibroseismic data, particularly vibroseismic data acquired in slip-sweep mode, by estimation and attenuation of the different harmonic components (see fig. 3). Said components are estimated from the Ground-Force signal using a separation technique with two options, namely least squares or time-frequency, both of which are adapted to the component to be extracted, and the noise is subdivided into classes. The harmonics specific to the recording in question are calculated and subtracted. Finally, the reference noises relative to each class are calculated and re-estimated using a multiple input/output method with dynamic management of the frequency band, which can be achieved using one of three options: global, cascade or multi-reference, followed by subtraction from the contaminated recording. The data quality is improved by means of appropriate source signal shaping.