Vibrator and processing systems for vibratory seismic operations

A seismic prospecting system comprising;

• a. means to generate an oscillatory time function of ground motion in the earth, responsive to a square wave reference signal, of a variable frequency, of selected frequency content and time duration, at a first point on the earth;
• b. means to provide an electrical transmitted signal of said oscillatory time function of ground motion, and wherein said electrical transmitted signal varies in phase from said reference signal due to phase shift in said means to generate, and means to digitize said electrical transmitted signal to 1 bit;
• c. means at a second point distant from said first point to detect said ground motion after transmission through the earth, and to produce a received signal, and means to digitize said received signal to 1 bit;
• and
• d. means to correlate said 1 bit electrical transmitted signal with said 1 bit received signal.

An improved seismic system comprising;

• a. a vibrator comprising two parts relatively reciprocable, one part attached to a reaction mass, and the other part attached to a base plate positioned on the earth;
• b. a reference sweep signal comprising a square wave signal of variable frequency of selected frequency range and time duration;
• c. means responsive to said square wave reference signal to drive said vibrator so as to impress alternately reversing forces on the earth at a first point on the earth;
• d. means to detect the alternating displacement of said baseplate, and to provide a transmitted signal representative of the seismic wave generated in the earth;
• and
• e. means to digitize said transmitted signal to 1 bit.

Apparatus for seismic prospecting comprising;

• a. a timing means to generate a train of time-spaced unidirectional electrical pulses of continually changing time interval between adjacent pulses;
• b. means to invert alternate pulses to provide a train of alternately reversing electrical pulses;
• c. force generating means responsive to said train of alternately reversing electrical pulses to apply to the earth a corresponding train of alternately reversing forces, at a first point on the earth;
• and
• d. means to detect the seismic wave generated by said force generating means after passing through the earth, at a second point distant from said first point, and means to produce a detected seismic signal.