The maximum reaction mass displacement in Vibroseis acquisition limits the energy that can be transmitted to the ground at low frequencies. A method to design the low-frequency end of Vibroseis sweeps that optimally uses the vibrator's mechanical and hydraulic specifications is proposed. This method, which is to a large extent independent of the near-surface elastic properties, requires vibrator specifications typically provided by the manufacturers and the desired ground-force power spectral density that depends on the geophysical requirements. The outputs of this sweep design approach are parameters such as the driving force envelope, the time-dependent sweep rate and the minimum sweep length, which are required input parameters in conventional sweep design methods. Comparisons of ground force measurements and surface seismic data obtained with the conventional and the proposed approaches are presented.
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