Harmonic decomposition of vibroseis data using a pure phase shift filter

In this paper I present an iterative process to decompose the harmonic distortion in the vibroseis data. It is based on a pure phase shift filter (PPSF) technique, which is computed from the phase spectrum of a deterrninistical "kth harmonic distortion" (O<k<I). The PPSF has been successfully applied to vibroseis data to eliminate harmonic distortions without degrading the data quality. The iterative decomposition process extends this ".kth harmonic distortion" to a "kth harmonic distortion" (k=m + k and m=I,2, ...,M), which is then used to design a pseudo PPSF. After the application of this pseudo PPSF to the harmonically distorted sweep (HDS) any harmonics sm(t) with m > k are removed .: An important property of this iterative decomposition is that the HDS is decomposed into the fundamental sweep so(t) and its harmonic distortions sm(t) (m=I,2, ..,M) in the real time domain. It is used for a rapid continuous monitoring of seismic vibrator performance.