USE OF VIBRATOR HARMONICS AS A SWEEP SIGNAL

摘要

In the conventional vibroseis method, the signal processing algorithms, including cross-correlation and deconvolution, are applied to convert the raw shot data into a seismic section. Vibrators are the best of the seismic sources and are widely used in exploration worldwide.The vibroseis seismic data quality is directly related to sweep signal harmonics. In other words, if the harmonic noise level increases, seismic quality decreases.In conventional vibrators, harmonic distortion is generated as a result of nonlinear coupling of vibrators and considered as coherent noises and consequently effects of these harmonic contaminations are subject to the elimination from the field records. Over the years different formalisms, using sweep parameters and phases, are proposed for the attenuation of these effects.In this study a new algorithm is developed using harmonic components of the signal sweep as an auxiliary source, instead of striving to eliminate them, in order to broaden the frequency bandwidth of the seismic imaging.Our approach is tested on synthetic and real data and results are discussed.