Abstract: An acoustical imaging system for producing high resolution medical images provides a method and apparatus for obtaining accurate velocity characterizations of samples within the human body, and for obtaining high resolution images of the samples by utilizing the velocity characterizations of the samples within the human body. The acoustical imaging system also provides a method and apparatus for efficient use of switching channels whereby for a transducer array having a plurality of transducer elements, a set of receiver channels which number less than the number of transducer elements in the array are assigned to a selected portion of the plurality of transducers in the array, wherein for any predetermined set of transducers symmetrically located about a selected transducer, the predetermined set equal in number to the number of receiver channels in the system, each receiver channel in the set of receiver channels is only assigned to one transducer in said predetermined sampling set.

Abstract: An acoustical imaging system for producing high resolution medical images provides a method and apparatus for obtaining accurate velocity characterizations of samples within the human body, and for obtaining high resolution images of the samples by utilizing the velocity characterizations of the samples within the human body. The acoustical imaging system also provides a method and apparatus for efficient use of switching channels whereby for a transducer array having a plurality of transducer elements, a set of receiver channels which number less than the number of transducer elements in the array are assigned to a selected portion of the plurality of transducers in the array, wherein for any predetermined set of transducers symmetrically located about a selected transducer, the predetermined set equal in number to the number of receiver channels in the system, each receiver channel in the set of receiver channels is only assigned to one transducer in said predetermined sampling set.

Abstract: This invention is concerned with systems for converting seismic waves received at various points at the surface of the earth into digital signals and the transmission of those digital signals from the geophone stations to a recording truck. Address registers located at the geophones are employed to permit periodic selective interrogation of the individual geophones. Typically, electric signals generated in the geophones, such as digital seismic signals, are time-multiplexed for return to a recorder over a common cable.

Abstract: This invention relates to an improved system for employing seismic techniques for surveying the subsurface structures of the earth. The invention relates particularly to an improved system for generating, collecting and processing the data during the course of exploration with a group of trucks that travel over the surface of the earth and intermittently stop to perform the required operations. The processing aids in the performance of the generating and collecting step and in the further processing of the collected data. And the data resulting from processing in this invention are transferred to a computer center for further processing. In this system, use is made of two programmable computers to facilitate concurrent processing of seismic waves received in successive setups in different ways.

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: 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.