Abstract: A method and system for using sonography to image the internal structure of geophysical and geologic models are disclosed. The sonography system includes a wand having a plurality of piezoelectric elements at an active surface thereof, each coupled to driver/receiver circuitry. Certain of the piezoelectric elements are selected as ultrasonic sources and receivers; the source/receiver designation may vary over time, as each of the elements may either generate or receive acoustic energy. A computer system, connected to the wand, receives signals from the receivers corresponding to reflected and refracted ultrasonic energy, and generates a zero offset trace image therefrom. In the geophysical case, the scale model is formed of materials such as plastics and rubbers having the desired properties for simulating the response of a portion or layer in the earth to ultrasonic vibrations.

Abstract: The present invention relates to a separation measuring method and a separation measuring apparatus for measuring the separation of objects, which have been displaced relatively, by using optical distance measuring equipments, and more particularly to a separation measuring method and a separation measuring apparatus most suitable for the detection of the activity of a fault to predict an earthquake. In the present measuring method, two optical distance measuring equipments are arranged near the separation plane, and carry out measurement simultaneously to measure a first distance and a second distance, and the difference between the first distance and the second distance is calculated to find the separation of the first and second objects, so that the separation can be measured by simultaneous observations. Since the present invention can find the separation by simultaneous measurements and therefore will not undergo the influence of meterological conditions such as atmospheric pressure, temperature, etc.

Abstract: A method for digitizing seismic traces comprising optically digitizing the seismic sections to produce a digitized image, normalizing the digitized image for brightness to produce a normalized digitized image, geometrically straightening the digitized image, and recovering the negative portions of said seismic traces to produce a fully restored wave form of the digitized image.

Abstract: A blast recorder and method for monitoring and processing vibrations from blasts, and for displaying the results in a nearly real time basis and in a manner which is easily interpreted by a relatively unskilled field worker and corresponds to a form which closely correspond to the real damage causing aspect of the blast than heretofore.

Abstract: An improved cableless seismic digital recording system is disclosed which records seismic-trace data generated by any type of seismic source, including high energy impulsive seismic sources, such as dynamite, and low energy surface seismic sources, such as vibrators and hammers. A seismometer, or geophone, is connected to a remotely deployed radio-controlled portable recorder which contains circuitry for sampling, digitizing, processing, storing, and recording seismic-trace data. Coded radio signals instruct each recorder to commence an operation or sequence of operations from a predetermined set of programmed instructions stored in program read only memory included in each recorder. Such operations include seismic-trace data acquisition; optional weighting and vertical stacking (summing); normalization; recording; and seismic source initiation.

Abstract: An improved method and apparatus for initiating seismic data storage in an Isolated Distributed Recording System. An encoded acoustic signal is generated by an acoustic energy source which is detected at an isolated distributed recorder where it is correlated with a preselected correlating signal. Upon sufficient correlation between the encoded acoustic signal and the preselected correlating signal, seismic data are stored. In the preferred embodiment, the invention relates to a method and apparatus for generating an encoded seismic signal utilizing a seismic energy source. The encoded seismic signal is correlated with a preselected correlating signal at an isolated distributed recorder; upon sufficient correlation between said signals, the isolated distributed recorder is triggered to store incoming seismic data commencing at the time the seismic data were generated and extending for a predetermined time interval.

Abstract: A method and apparatus for selectively controlling isolated distributed recorders in an Isolated Distributed Recording System. Selection and control of isolated distributed recording units comprising a seismic data gathering Isolated Distributed Recording System are effected by transmitting preselected encoded acoustic seismic signals to which the isolated distributed recorders have been preconditioned to respond by effecting a desired control action. The same encoded acoustic seismic signal may also provide the seismic data for the experiment. Each isolated distributed recorder is conditioned to respond to several encoded acoustic signals, to discriminate against noise, and/or to respond to one such encoded acoustic signal by effecting a plurality of control actions at the isolated distributed recorder.

Abstract: A transcriber system for receiving previously recorded data in a first medium and outputting the data in a second medium, and which includes at least one input device for receiving the data in the first medium, an output device for outputting the data in the second medium, a control and processing device which controls the input and output devices for a selected mode of transcription and in one embodiment, for selected processing of the data in the field. In one embodiment, the transcriber system receives seismic data from tape cartridges and/or solid state memory devices and outputs the seismic data onto a magnetic tape for later processing and analysis or transmission to a remote facility via a satellite link. The transcription system can include a printer/plotter for analysis of different seismic data recording and processing arrangements in the field.

Abstract: A variable amplitude/phase color seismic display is provided which increases the ease with which interpreters can locate peaks, troughs and other information of interest.

Abstract: The present invention relates to a ground position controller utilizing a microcomputer system interconnected to a digital field system (DFS) via a system bus, for generating, formatting and displaying information (for insuring integrity of field operations) under a variety of shooting and collecting conditions.

Abstract: Test features are incorporated in an improved cableless seismic digital recording system recorder. The improved recorder facilitates application of earlier cableless seismic digital recording systems to situations in which seismic-trace data is generated by low energy surface seismic sources, such as vibrators and hammers. A seismometer, or geophone, is connected to a remotely deployed radio-controlled portable recorder which contains circuitry for sampling, digitizing, processing, storing, and recording seismic-trace data. Coded radio signals instruct the recorder to commence an operation or sequence of operations from a predetermined set of programmed instructions stored in program read only memory included in the recorder. Such operations include data acquisition; optional weighting and vertical stacking (summing); normalization; recording; and seismic source initiation. Test features include control panel display of operational status and verification of gain-ranging amplifier operation.

Abstract: A digital recorder and method for digitizing and recording seismic events, the recorder being capable of lengthy stand-by periods during which it records lesser events of little interest in a static buffer and then displaces these events with more recent events when the static buffer is full. The recorder is self powered and controlled by a microprocessor to transfer strong-motion signals representing important seismic events from the static buffer into a static memory which is kept alive by suitable back-up batteries and comprises a cartridge separable and retrievable from the recorder after a major seismic event. The information in the recorder also is accessible through a serial port for reading out to a central data processor. The seismic information is specially compressed and formatted to increase the amount of data recorded by eliminating data that is essentially redundant.

Abstract: A system for testing seismic signal recording equipment wherein a test signal is generated which simulates the output of at least one seismic sensing device, and, thereafter, the test signal is applied to the seismic signal recording equipment. The test signal is recorded by the seismic signal recording equipment and the recorded signal is compared with the generated test signal to evaluate the performance characteristics of the seismic signal recording equipment. The system can include circuitry to vary component elements of the test signal to test different performance characteristics of the seismic signal recording equipment, as well as ability to generate a random noise signal for addition to the test signal.

Abstract: Amplitude-versus-time information of a seismic time section is automatically migrated so that events on the time section are displaced, both vertically and horizontally, into positions on a seismic depth section that correspond to actual spatial positions of seismic reflectors in the subsurface. The migration is continuous in the sense that it moves the entire waveforms, not merely previously picked events.

Abstract: A display system is provided in which the data from a plurality of data channels is displayed on a cathode ray tube (CRT) display device. Automatic gain control is utilized to ensure that essentially the entire screen of the CRT display device is filled even if the number of data channels available to supply data to be displayed varies. Digital gain ranging circuitry is provided to ensure that the automatic gain control circuit is not overloaded by a large variation in the number of data channels available to supply data to be displayed. Circuitry is also provided to enable the highlighting of data from a particular data channel on the CRT display device to thereby provide easier viewing of the data, from that particular data channel, for an operator.

Abstract: A new and improved method of forming a color graphic display from seismographic input data is disclosed. The input data sequence is processed to obtain the absolute value of each amplitude value and to select the maximum amplitude value of each oscillation of the waveform. A predetermined number of the largest selected values are classified into a first range of values, the remaining values are scaled according to magnitude into a preset number of ranges and an assignment table is formed with each range being represented by a primary or secondary color. Data corresponding to a first group of ranges of input data is processed to form a representation for a particular color. Similarly, the remaining data groups, corresponding to the remaining ranges, are processed to form a representation of the remaining colors. The image of each representation is sequentially transferred to a sheet and the images are colored with their respective colors, thus producing a color display of the seismic data.

Abstract: The specification discloses a method and system wherein an operator interacts with an automatic data processing and display system to classify and sort subsurface reflective surfaces or segments in a multidimensional context. The technique utilizes a properly programmed general purpose digital computer in combination with a plurality of storage tube display screens. Seismic reflection data in the form of computer picked reflection segments, hereinafter referred to as seismic segment data, produced from previous computer processing steps is entered into the computer. Displays of the velocity, amplitude, dip and length of the segments in a space gate are then provided on the display screens. A data responsive surface having a network of conductive wires and a detecting stylus are utilized by the operator to operate upon the displayed segment data to classify primary segments and to define boundaries relative to each of the parameter displays.

Abstract: A novel seismogram display and method for making same are provided wherein a portion of the areas under certain ones of the positive and negative wavelet lobes of each seismic trace is shaded. Each shaded area originates at or near a null point. The novel seismogram allows an interpreter to correlate both partially shaded lobes per wavelet, instead of one completely shaded, single lobe per wavelet. The invention therefore greatly simplifies and enhances the correlation and interpretation process.

Abstract: A seismic triggered seismograph (10) has a transducer (12) that measures particle vibration along three orthogonal axes and a microphone (14) which measures atmospheric overpressure. The four parameters measured produce signals which are passed through delay circuits (58, 60, 62, 90) and then connected for recording on magnetic tape (21). The seismic signals are examined before being input to the delay circuits (58, 60, 62) and when any of the signals exceeds a predetermined threshold, a tape transport (154) and recording mechanism are activated so that the signals are recorded when they emerge from the delay circuits. Both the delay circuits (58, 60, 62, 90) and the magnetic recording are implemented with analog format. At the end of a predetermined time interval following a seismic event, a calibration signal is applied to the magnetic recording. Following the calibration signal, the transducer (12) is activated by a standard amplitude signal for indicating calibration of the transducer (12).

Abstract: Apparatus, for use with a chart recording fathometer, for receiving loran C time difference/line of position information and for recording that information in vertical columns on the chart in juxtaposition with water depth information from the fathometer. The apparatus requires no modifications to conventional recording fathometers and is simply electrically connected to the fathometer's transducer.

Abstract: Multiplexed seismic data representing a plurality of seismic channels intensity modulates each sweep of the electron beam of a cathode-ray tube. Each successive sweep of the electron beam is photographically reproduced on a rotating drum plotter to provide a seismic record section. The modulation of the cathode-ray tube is further controlled to provide for various seismic trace presentations on the record section, including wiggle traces, variable area traces, wiggle-variable area traces, and symmetrical-variable area traces.

Abstract: Multiplexed seismic data representing a plurality of seismic channels intensity modulates each sweep of the electron beam of a cathode-ray tube. Each successive sweep of the electron beam is photographically reproduced on a rotating drum plotter to provide a seismic record section. The sweep signal for controlling the electron beam is automatically gain controlled so that the number of seismic traces per inch remains constant.

Abstract: In seismic exploration of water-covered areas of the earth, a seismic cable containing seismic energy detecting means spaced along the cable is used. The detecting means are grouped into one or more arrays situated along the length of the cable, and each array is divided into a plurality of groups. The detector outputs within each group are connected in parallel within the cable. Selected group outputs, corresponding to varying segmental lengths along the cable, are summed to enhance seismic data signal-to-noise ratio. The summed signal used for seismic analysis is determined by the maximum array segmental length over which reflected seismic signal components are substantially phase correlated. This length varies with record time, with geologic dip of the earth layers, and with distance of the detectors from the seismic source. This invention permits the selection, during seismic analysis, of the array segmental length that provides the most useful seismic data.

Abstract: In a seismic data processing system, seismic data in channel-sequential format intensity modulates the electron beam of a cathode-ray tube. A photographic drum plotter provides a recording of the seismic data displayed on the face of the cathode-ray tube. A screen of multilined squares is placed in contact with the photographic film on the drum plotter so that the seismic data is recorded in a half-tone, variable-density format.

Abstract: A new and improved color display of geophysical and other scientific and industrial or similar technological data readily and quickly obtained from input data and containing color indications of variables in the data in a form better adapted for interpretation by analysts.

Abstract: The present invention provides a new and improved method of displaying a plurality of seismic sections of geophysical data on two-dimensional surface in an isometric view, while the display so formed is a display of increased information content.

Abstract: A method and apparatus for marine seismic prospecting in which a long spacing linear array of seismic detectors is spaced from a seismic source and connected to a recording apparatus on a survey ship. A short spacing linear array of seismic detectors is also spaced from the seismic source and signals thereof supplied to suitable channels of the recording apparatus in common with some of the signals from the long spacing detector array. The principal and auxiliary signals in the common channels are distinguishable as a result of relative amplitude and time separation.

Abstract: Cableless seismic recorders employ a small, mobile amplifier-recorder in which preferentially the recorder tape contains in digital form both identification information (called header data) and the response of a plurality of seismometers (seismometer group) to a seismic source, the whole arrangement requiring no cable connection between the various recorders and the control truck. Since this system is energized by a battery, it has not been previously possible to use summation techniques, as required, for example, when any repetitive seismic source is employed. Such a system is described here. Low power consumption is obtained by using a plurality of recirculating, dynamic shift registers connected in cascade. Feedback from the output of this cascade register chain under synchronized condition permits the seismometer response to the second use of the source to be additively superimposed upon the stored data from the first use of the source, and so on.

Abstract: In seismic prospecting a local response is achieved by striking a hammer on the ground, and the recording apparatus is arranged to be triggered by the hammer to run from a short time before the impulse to a predetermined time after it. The impulse is recorded into one channel and the reflections into another, and the latter are slowed down by successive recordings to a speed where they can be mechanically plotted. The impulse signal in the other channel is used as a timing and control signal for the re-recording and playbacks.

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: In seismic group recording, each seismic trace is initially digitally recorded by a small, portable, magnetic recorder placed near the corresponding seismometer recorder group. A large number of such groups and corresponding recorders are placed over an area or along a profile line, and from a control point, only those specific recorders needed for a given set of record traces are turned on at any time by transmitting a set of coded signals over a communications link which is usually a radio link. The bandwidth restrictions of licensed geophysical radio channels can cause difficulty in this communications system from control point to the various seismometer groups. Accordingly, this disclosure covers an improvement in the communication method employed in a seismic group recorder system. U.S. Pat. No. 3,806,864 teaches the employment of audio frequency encoding on a frequency-modulated band-limited channel with a maximum audio frequency of approximately 3 kilohertz.

Abstract: A new and improved color display of geophysical and other scientific and industrial or similar technological data readily and quickly obtained from input data and containing color indications of variables in the data in a form better adapted for interpretation by analysts.

Abstract: A new and improved method of forming color graphic displays from input data is disclosed. In the displays so formed differing colors quantitatively identify and indicate differing values or ranges of values of the data. The input data are processed to determine sample values for data display points, and numerical codes from an assignment table are assigned according to the sample values. The assigned codes are arranged into output sequences for each of plural component displays of the final display, and the component displays formed and displayed in superposition to form the color graphic display with colors therein graphically indicating the data.

Abstract: This invention concerns a status alarm for a seismometer group recorder. In using group recorders, the automatic recording feature leaves the field personnel (the user) with minimum confidence that operations are satisfactory, in the absence of a status alarm. An alarm functions when a particular group recorder has been energized and is presumptively ready for operation. The alarm system is actuated only when the major systems within the group recorder are ready to operate. The alarm may be either visual or aural or both.

Abstract: A synthetic display is provided, in cross-sectional form, of the theoretical strength of seismic reflections. The theoretical strength is computed from calculated inverval-velocity values and known or estimated density values. By comparison of this synthetic reflection-strength display with the observed reflection-strength display, useful conclusions may be drawn about the nature of geological materials and the complex origin of reflections.

Abstract: Seismic signals from detectors forming split spreads are utilized to correct for weathering, elevation, and the like signals from detectors forming an expanded spread. The signals of the seismic section delineated by the expanded spread have applied thereto time changes under the control of a hyperbolic generator. There are generated as a result of the sweeping across the section and lengthwise thereof of the seismic signals the generation of functions utilized to provide normal moveout corrections of greater precision or accuracy than heretofore. With the normal moveout corrections of greater accuracy applied to the signals of the seismic section, additional corrections are made for dip and thereafter for delineation of the velocity characteristics of the earth along the stratigraphic column. There is included provision not only for identification of primary reflections and multiples but also for the elimination of multiples from the signals of the seismic section.

Abstract: A method and apparatus for detecting the instant on explosive is detonated by way of an optical signal. A length of optical fiber has one end wrapped around or positioned near the explosive with the other end coupled to a remote recorder. The end of the fiber at the explosive has been cleaved so as to internally reflect an optical signal propagating therein. A beam of radiation is launched into the fiber at the record where it is reflected from the distal end and redirected back to the recorder where it is detected. Detonation of the explosive destroys the reflective end of the optical fiber causing the radiation to leak from the broken fiber end. The instant the recorder does not receive the reflected radiation is the instant of the explosive detonated.