Some issues in vibrator data processing

Abstract

Recent improvements in vibrator control, such as the use of phase and amplitude control of ground force, require that some of the issues relating to vibrator data processing be reviewed. One central issue concerns the polarity of processed vibrator data as compared to processed dynamite data. At the field processing stage, alternate methods of correlation that include conventional zero-phase correlation, zero-phase inverse filtering, and minimum-phase inverse filtering are compared to determine their compatability with subsequent steps of wavelet estimation and inverse filtering or deconvolution. This issue is shown to be of particular importance when nonlinear sweeps are used. Conventional correlation is shown to be responsible for causing deconvolution to induce different phase shifts on the data when different spectral pre-emphasis sweeps or methods are used. Techniques for avoiding this problem are reviewed.