Phase Shift Effect in Vibroseis Down-sweep Data

For increasing signal-noise ratio of seismic records, vibrator arrays (combination vibroseis) can be used by phase controlling to concentrate seismic waves into a directed beam so as to enhance energy of seismic waves. When the concentration zone of the directed seismic beam is coincident with the range of the geophone arrangement, the energy intensity of the synthetic seismogram with the vibrator arrays is obviously higher than that with a single vibrator, and the uniformity of the amplitude of seismic wave for the combination array vibrators is obviously better than that of one vibrator. However with some delay in phase controlling, the summation amplitude of seismic waves will be truncated or restricted specially at high frequency band. In this study, I appointed the impact of the phase delay (delay time) between a group of vibrators sweeping at the same time. I established a formula to obtain the effect of phase delay. The mathematical equations are explained in details in the body of the article in the section titled “Seismic wave beams and phase shift effect on vibroseis sweeping”. Through Specifies of the phase shift the resolution and the accuracy of the seismic data can be improved