Abstract: In a seismic recording and processing system in which a line of sources and a separate line of receivers are provided and each of the source operations from each of the source points is recorded on all receiver points. A method is described for determining the differential static correction between each adjacent pair of source points in terms of the differences in travel times from each pair of source points, to all pairs of receiver points. This is provided even though the lines of source points and receiver points may be parallel to or at angles to each other, and the spacings of source points and receiver points in their separate lines may be the same or different.

Abstract: The method of determining the magnitude of the differential static correction between adjacent records in seismic record processing, that involves the steps of: recording a first multi-trace record responsive to a first seismic wave generated at a first source point; recording a second corresponding multi-trace record responsive to a second seismic wave at a second source point, which is adjacent to the first source point; correlating a first trace of the first record with the corresponding first trace of the second record, and determining the first time difference between the two first traces of said two records; repeating the correlation step and determining the time differences for a plurality of N pairs of traces; adding all of the N time differences and dividing the sum by N to find the net difference in static correction between the first and second source points.

Abstract: The method of determining the magnitude of the differential static correction between two selected adjacent receiver points D, E, in a linear seismic array, that involves the steps of: recording a first multi-trace record responsive to a first seismic wave generated at a first source point C on one side of D, E at any distance; recording a second corresponding multi-trace record responsive to a second seismic wave at a second source point F on the opposite side of D, E at any distance; correlating a first trace CE with a second trace CD of the first record to obtain a first time difference R; correlating the corresponding first trace FD with a second trace FE of the second record to get a second time difference S; and determining the value of K = (R - S)/2, where K is a value of the static correction equal to the difference in the travel time through the weathered layer at D and E. The process can be repeated for other positions of C, F to obtain other independent values of K.

Abstract: A system and method for carrying out seismic operations with low energy sources, which involves operating the source at spaced points along a seismic spread, the source points are spaced far enough apart so that their seismic waves originate at different points and travel by different paths to the geophones. The geophone outputs cannot be time stacked. The geophone signals are amplified at constant gain and digitized to 1 bit. If the low energy source is a vibratory source, the 1 bit signals are correlated with a 1 bit version of the sweep signal. The resulting correlograms are digitized to 1 bit and then C.D.P. stacked and displayed. If the low energy source is impulsive, the 1 bit amplified signals are C.D.P. stacked and displayed.

Abstract: In a seismic system in which signals from a plurality of geophones are carried by pairs of conductors to each of a plurality of array terminals, where the geophone signals are converted to square wave signals, and on successive commands, the square wave signals are sampled, the samples are temporarily stored, and are then transmitted to storage means, the improved method of transmitting the geophone signals from the geophones to the array terminals, comprising; amplifying and square waving the geophone signals at the geophones, and transmitting the square wave signals to the array terminals. Included also are steps to modulate carrier signals in synchronism with the square wave signals to form bursts of carrier signals which are transmitted to the array terminals, where the bursts of carrier signals are detected and the square wave signals are regenerated, and sampled.

Abstract: This abstract describes a system for the field recording of seismic data in which a plurality of geophone outputs are connected to an array terminal. Each geophone is connected to a fixed gain differential amplifier of high gain. The outputs of the amplifiers are square wave and each output goes to one of the parallel inputs of a parallel to serial convertor, through gate means. On a first command from an array controller in a distant recording truck, the gate means are momentarily opened, to store a single bit in each channel corresponding to the sign of the square wave, in the convertor inside the array terminal. The convertor then reads out as a train of serial bits, the stored pulses. This train of single bit signals is carried to the array controller through each of the other array terminals by a single pair of conductors, and stored on a magnetic recording means.

Abstract: A method of carrying out vibratory seismic operations with the object of minimizing correlation noise lobes, comprising, repeating a vibratory source a plurality of times each with a different sweep, having different terminal frequencies, correlating each received signal with its corresponding sweep, and stacking the resultant correlograms. The range in terminal frequencies for the plurality of sweeps should preferably be in the range of one octave or more. Another method of operation is to vary the time durations of the successive sweeps, preferably over a range of 2 to 1, and correlating the received signals and sweeps, and then stacking. In a third method of operation both the time durations and the terminal frequencies are varied. The successive repetitions of the source can be at the same source point and the results straight stacked, or they can be at different independent source points and the results CDP stacked.

Abstract: This abstract describes a system for acquisition of analog signals at a plurality of sensors, carrying these signals in groups of M channels to each of N spaced-apart array terminals, processing each signal in the array terminals by separately amplifying, digitizing to 1 bit and storing as single bit pulses, one for each channel, in a parallel to serial convertor. Each of the convertors in each of the array terminals are operatively connected in series and to an array controller, which also controls a disc magnetic recorder. On command, the convertors are read out in series as sequential trains of M bits into core memories and then stored on the disc. Successive, bit samples at subsequent digitizing intervals are stored on the disc, to form a first record. Subsequent records are processed, stored in core memory and composited with previous records stored on the disc.

Abstract: This abstract describes a system for the field recording of seismic data in which a plurality of geophone outputs are connected to an array terminal. Each geophone is connected to a fixed gain differential amplifier. A shifting function is produced which is added to the amplified geophone signal to form a sum signal which goes to an axis crossing coder, (AXC). On a first command from an array controller in a distant recording unit, the AXC is commanded to produce axis-crossing-coded pulses of the instantaneous sum signals. These pulses are stored in a parallel-to-serial converter inside the array terminal. On a second command from the array controller the converter reads out as a train of serial bits, the pulses stored in the converter. This train of single bit signals is transmitted to the array controller by a single pair of conductors, and stored on a magnetic recording means.

Abstract: A system for the field recording of seismic data in which a large plurality of geophones are arrayed on the earth and divided into groups, and each group is connected to an array terminal. All of the array terminals are connected in series, by cables, with the last terminal connected to a recording unit. In each of the terminals there are means to process the geophone analog signals by amplifying at constant gain and digitizing to 1 bit to provide a plurality of 1 bit pulses, which are stored in parallel in a parallel to serial convertor.

Abstract: This abstract describes a system for acquisition of analog signals at one or more sensors, carrying these signals in groups of M channels to each of N spaced-apart array terminals, processing each signal in the array terminals by separately amplifying, adding to a shifting signal of selected amplitude, axis-crossing-coding these sum signals and storing as single bit pulses, one for each channel, in a parallel to serial converter. Each of the converters in each of the array terminals are operatively connected in series and to an array controller, which also controls a disc magnetic recorder to run at constant speed. The disc generates a disc clock, and responsive to the disc clock the converters are read out in series as a sequential train of MN bits and stored on the disc. Successive samples at subsequent digitizing intervals are stored on the disc, to form a first record.Subsequent records can be processed, coded and recorded, and composited with previous records on the disc.

Abstract: This abstract describes a system for the field recording of seismic data in which a large plurality of geophones are divided into groups and each group is connected to an array terminal. All of the array terminals are connected in series, by cables, with the last terminal connected to a recording unit. In each of the terminals there are means to process the geophone analog signals by amplifying and adding them to a selected shifting function, and axis-crossing-coding (AXC) the resulting sum signals to provide a plurality of pulses which are stored in a prallel-to-serial converter. In addition, each of the terminals contains a buffer register.