Comb Filters Patents (Class 367/44)
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Patent number: 11360184Abstract: Sensor receiver nulls and null steering. One example embodiment is method in which a direction from a sensor position to a noise source is determined. A coordinate rotation is applied to a first set of signal values, wherein each signal value of the first set of signal values is based on an output of a corresponding component of a three-component particle motion sensor at the sensor position. The applying generates a rotated set of signal values. The coordinate rotation comprises a coordinate rotation transforming a first set of coordinate axes to a second set of coordinate axes, wherein the first set of coordinate axes has each coordinate axis aligned with a corresponding component of the three-component particle motion sensor at the sensor position, and the second set of coordinate axes comprises a first axis pointed in a direction opposite the direction from the sensor position to the noise source.Type: GrantFiled: August 22, 2018Date of Patent: June 14, 2022Assignee: PGS GEOPHYSICAL ASInventors: Paul Edwin Murray, Robert Alexis Peregrin Fernihough
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Patent number: 9979380Abstract: A method for optimizing processor operation in a processing system including one or more digital filters is provided according to the invention. The method includes generating initial filter coefficients for the one or more digital filters of the processing system, determining one or more initial filter coefficients for at least one digital filter of the one or more digital filters that can be dropped and dropping the one or more initial filter coefficients. Dropping the one or more initial filter coefficients reduces a total number of filter coefficients to be used by the processing system.Type: GrantFiled: July 30, 2008Date of Patent: May 22, 2018Assignee: Micro Motion, Inc.Inventors: Craig B McAnally, Paul J Hays
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Patent number: 9747888Abstract: A reverberator for reverberating an audio signal includes a feedback delay loop processor for delaying at least two frequency subband signals representing the audio signal by different loop delays to obtain reverberated frequency subband signals.Type: GrantFiled: September 4, 2015Date of Patent: August 29, 2017Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.Inventors: Bernhard Neugebauer, Jan Plogsties, Juha Vilkamo
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Patent number: 9696444Abstract: Systems, computer readable media, and program code to provide for filtering noise and/or restoring attenuated spectral components in acoustic signals, are provided. An exemplary embodiment of a system is configured for dynamically filtering each of a plurality of raw FFT data samples of a record to remove or attenuate background noise contained therein to thereby produce a corresponding plurality of cleaned FFT data samples. The sample-specific background noise is removed or attenuated by a record-specific dynamic filter to produce the corresponding cleaned FFT data samples.Type: GrantFiled: September 12, 2014Date of Patent: July 4, 2017Assignee: Saudi Arabian Oil CompanyInventor: Yunlai Yang
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Patent number: 9684087Abstract: Methods of providing for filtering noise and/or restoring attenuated spectral components in acoustic signals, are provided. An exemplary embodiment of a method includes dynamically filtering each of a plurality of raw FFT data samples of a record to remove or attenuate background noise contained therein to thereby produce a corresponding plurality of cleaned FFT data samples. The sample-specific background noise is removed or attenuated by a record-specific dynamic filter to produce the corresponding cleaned FFT data samples. The method can also include restoring the attenuated high-frequency components of the cleaned data samples through application of a record-specific Restoring Processor at least partially defined by a portion of the cleaned data samples and a Gain Function to thereby produce cleaned and restored data samples, and applying an inverse transformation to convert the cleaned and restored data samples into cleaned and restored data samples in time domain data.Type: GrantFiled: September 12, 2014Date of Patent: June 20, 2017Assignee: Saudi Arabian Oil CompanyInventor: Yunlai Yang
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Dynamically allocating different numbers of bits to windows of a series representing a seismic trace
Patent number: 9541658Abstract: To process seismic data, a set of data values representing a seismic trace is received, and amplitudes of data values associated with plural groups in the set are analyzed. Different numbers of bits are dynamically allocated to at least some of the groups of the set according to the analyzing.Type: GrantFiled: July 11, 2008Date of Patent: January 10, 2017Assignee: WESTERNGECO L. L. C.Inventor: Francis G. Sherrill -
Patent number: 9384744Abstract: An audio signal coding device divides a frequency spectrum obtained from an input digital signal to a plurality of bands, scales and quantizes divided frequency spectra based on a scalefactor of each of the bands and a common scale which is common to the plurality of bands, and codes quantized frequency spectra. The audio signal coding device includes a band number determination unit configured to calculate a number of coding bands for coding the quantized frequency spectra, and a common scale estimation unit configured to estimate the common scale in accordance with the number of coding bands.Type: GrantFiled: November 27, 2012Date of Patent: July 5, 2016Assignee: Socionext Inc.Inventors: Mari Asami, Tomoya Fujita, Jun Ono, Shusaku Ito, Yoshiteru Tsuchinaga, Miyuki Shirakawa, Sosaku Moriki
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Patent number: 9245520Abstract: A reverberator for reverberating an audio signal includes a feedback delay loop processor for delaying at least two different frequency subband signals representing the audio signal by different loop delays to obtain reverberated frequency subband signals.Type: GrantFiled: April 20, 2012Date of Patent: January 26, 2016Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.Inventors: Bernhard Neugebauer, Jan Plogsties, Juha Vilkamo
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Patent number: 9043155Abstract: A technique includes processing seismic data indicative of samples of at least one measured seismic signal in a processor-based machine to, in an iterative process, determine basis functions, which represent a constructed seismic signal. The technique includes in each iteration of the iterative process, selecting another basis function of the plurality of basis functions. The selecting includes based at least in part on the samples and a current version of the constructed seismic signal, determining a cost function; and interpreting the cost function based at least in part on a predicted energy distribution of the constructed seismic signal to select the basis function.Type: GrantFiled: September 29, 2011Date of Patent: May 26, 2015Assignee: WESTERNGECO L.L.C.Inventors: Massimiliano Vassallo, Ali Ă–zbek, Dirk-Jan Van Manen, Anthony D. Curtis, Kurt Eggenberger
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Publication number: 20140112098Abstract: A method for calculating intermodulation noise generated with one or more land seismic sources. The method includes receiving seismic data (g) generated by actuating the one or more land seismic source with a single sweep; selecting a number of detectors (a-f) that detect a subset (ga-gf) of the seismic data (g); estimating earth responses (ha1-hf1) based on (i) the subset seismic data (ga-gf) and (ii) a ground force (gf) of the one or more land seismic source; calculating plural intermodulation noises (noiseA1-noiseF1) for the number of detectors based on the earth responses (ha1-hf1); and removing the plural intermodulation noises (noiseA1-noiseF1) from corresponding detector signals (ga-gf) to mitigate the intermodulation noise effect.Type: ApplicationFiled: March 15, 2013Publication date: April 24, 2014Applicant: CGGVERITAS SERVICES SAInventor: John SALLAS
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Patent number: 8644110Abstract: Methods and systems utilizing seismic sensors configured or designed for use in seismic signal detection are provided so as to reduce the occurrence of spurious responses of the sensors. A method of seismic surveying using a seismic sensor may include the steps of deploying the seismic sensor at a location for seismic signal detection and acquiring seismic signals. The seismic signals may include high frequency response signals containing spurious response signals at an identifiable bandwith. The method may further include applying spurious response cancellation based on the bandwidth location of the spurious response signals and generating modified seismic waveforms having extended frequency bandwidth.Type: GrantFiled: May 20, 2011Date of Patent: February 4, 2014Assignee: Schlumberger Technology CorporationInventor: Masahiro Kamata
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Patent number: 8614578Abstract: The present disclosure relates to determining the attenuation of an electromagnetic signal passing through a conductive material. An antenna is provided and placed in relatively close proximity to the conductive material. An alternating current is passed through the antenna and the impedance of the antenna is measured. The attenuation is determined using the measured impedance. A single frequency measurement may be made, or multiple measurements using different frequencies may be made. Grouped parameters based on properties of the material and the frequency of the current are used to relate the coil impedance to the attenuation. A current frequency for which the ratio of the antenna's resistive part of the impedance to the angular frequency of the current is substantially insensitive to at least one of the parameters is preferred.Type: GrantFiled: December 18, 2009Date of Patent: December 24, 2013Assignee: Schlumberger Technology CorporationInventors: Guozhong Gao, H. Frank Morrison, Hong Zhang, Richard A. Rosthal, David Alumbaugh, Cyrille Levesque
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Patent number: 7447114Abstract: A method and apparatus for seismic trace matching to well logs.Type: GrantFiled: August 31, 2005Date of Patent: November 4, 2008Assignee: Geotrace Technologies, Inc.Inventor: John DuBose, Jr.
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Patent number: 7433265Abstract: Coherent wave noise energy is removed from seismic data by modeling both the P-wave primary energy and the coherent wave noise energy. The P-wave primary energy is modeled first and then subtracted from the input data. The data with the P-wave primary energy removed is used as the input for coherent wave energy removal. The coherent wave energy is modeled and subtracted from the original input data, i.e. the data input into P-wave primary removal. This leaves a dataset with P-wave primary energy and noise energy not related to coherent waves. This method can be utilized to remove all types of coherent noise with a velocity difference to the desired P-wave primary energy or with a different type of moveout (change of time of arrival with source-receiver distance) such as, for example, linear moveout.Type: GrantFiled: October 4, 2005Date of Patent: October 7, 2008Assignee: Fairfield Industries, Inc.Inventors: Kenneth L. Craft, Bryan C. Keller
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Patent number: 5995446Abstract: A method is described for providing improved seismic data to a driller to indicate position and spatial extent of a drilling target which may be up to several hundreds of feet ahead of a drill bit. In one embodiment, the method includes the steps of: survey design and data modeling, and definition of a drilling target point and a drilling interruption point; drilling down to a depth at which drilling will be interrupted; interruption of drilling; look-ahead borehole seismic survey (VSP); continuation of drilling; data processing and interpretation; coordinate update for optimum target intersection; and steering of drilling by borehole seismic data interpretation.Type: GrantFiled: April 21, 1998Date of Patent: November 30, 1999Assignee: Schlumberger Technology CorporationInventors: Joerg H. Meyer, Leslie A. Bennett
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Patent number: 5583826Abstract: The present invention relates to a method of extrapolating a set of traces recorded by means of an array of sensors, in the context of a geophysical prospecting process, the method comprising the steps consisting in: i) approximating a minus Laplacian L.sub.0 (k.sub.x,k.sub.y)=k.sub.x.sup.2 +k.sub.y.sup.2 by the sum of two one-dimensional filters; and ii) approximating an extrapolation operator F.sub.0 by a polynomial of the minus Laplacian L.sub.0. The invention also provides a system for geophysical prospecting.Type: GrantFiled: May 27, 1993Date of Patent: December 10, 1996Assignee: Compagnie Generale de GeophysiqueInventor: Robert Soubaras
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Patent number: 5576977Abstract: A filter for eliminating the effects of fluorescent lights on microwave transceivers uses a digital comb filter to eliminate signals at the AC power line frequency and its harmonics. A preferred embodiment has an A/D converter or sampler for sampling and digitizing an output signal from a microwave transceiver. The digitized signal is processed by a processor which implements the digital comb filter by performing a recursion equation. The inventive filter may also have a selector for selecting the sampling frequency. By selecting a desired sampling frequency, the filter may be easily adapted to filter out a different AC power line frequency. Thus, the inventive filter is easily adaptable for use in different countries having different AC power line frequencies.Type: GrantFiled: April 27, 1995Date of Patent: November 19, 1996Assignee: Alarm Device Manufacturing CompanyInventor: Kenneth Eskildsen
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Patent number: 5067112Abstract: In seismic exploration, seismic reflections from subsurface formations are recorded in the form of a time-distance array of seismic traces. This array is transformed into a frequency-distance domain. Frequencies at which coherent noise resides within the frequency-distance domain are determined. Wavenumbers corresponding to such frequenices are removed by filtering. The wavenumber-filtered, frequency-distance domain of seismic traces are then transformed back into a time-distance array of seismic traces.Type: GrantFiled: January 4, 1991Date of Patent: November 19, 1991Assignee: Mobil Oil CorporationInventors: Robert A. Meek, Andrew F. Linville, Jr.
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Patent number: 4875166Abstract: A low-cut filter is provided which has a frequency response with its low frequency end attenuation limited. The low-cut filter has the effect of increasing effective channel bandwidth while simultaneously allowing low frequency signals from deep within the earth to be included in the output signal. Effective channel bandwidth is increased because low frequency seismic signals are attenuated, automatically allowing channel gain to be increased by a gain ranging amplifier. Increased channel gain automatically amplified the low-amplitude high-frequency end of the spectrum resulting in increased effective bandwidth. A high frequency boost filter is provided whereby the high frequency signal components of the seismic signals may be further relatively amplified thereby enhancing the channel effective bandwidth. The boost filter is provided in the system's input stage in order to keep its effect on system input noise to a minimum.Type: GrantFiled: October 9, 1987Date of Patent: October 17, 1989Assignee: Input/Output, Inc.Inventors: Paul E. Carroll, Roy W. James, III, Charles K. Bowen, Gillan C. Smith
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Patent number: 4853902Abstract: An improvement in a method of treating seismic data in which predictive noise, as measured along one of the axes is discriminated and subtracted from the total signal along another of the axes recorded by geophone recording the reflection from subterranean strata of energy input from a source at the surface.Type: GrantFiled: March 7, 1988Date of Patent: August 1, 1989Assignee: Atlantic Richfield CompanyInventor: Dennis Corrigan
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Patent number: 4757480Abstract: A method and apparatus for filtering seismic data are provided. More particularly, the method and apparatus of the present invention attenuate surface wave generated noise in seismic-trace signals. Seismic data comprising multicomponent seismic-trace signals acquired with single station, multicomponent geophone arrays are comb filtered to produce a plurality of comb filtered signals for each component of the multicomponent seismic-trace signal. The comb filtered signals are sorted into orthogonal sets and a measure of rectilinearity for each orthogonal set is obtained. Surface wave generated noise can then be attenuated in each orthogonal set with its respective measure of rectilinearity.Type: GrantFiled: April 24, 1986Date of Patent: July 12, 1988Assignee: Amoco CorporationInventor: Paul R. Gutowski
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Patent number: 4730281Abstract: A bucket brigade filter is disclosed having a feedback loop resulting in a tight comb structure filter response whereby a periodic noise and all its harmonics may be removed from a signal. Scalers featuring selectively variable scaler parameters permit prompt adaptation to changes in the noise period, rapid initialization of the filter to an operating condition and adjustable stopband widths of the filter frequency response. Sampling of the input data signal may be synchronized to the periodic variations of the noise to be eliminated from the signal.Type: GrantFiled: March 15, 1985Date of Patent: March 8, 1988Assignee: NL Industries, Inc.Inventors: Paul F. Rodney, Richard A. Kester
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Patent number: 4312050Abstract: An apparatus and method for improving seismic resolution involving the application of scaling factors to seismic data which compensate for amplitude decay as a function of time, frequency and source-to-receiver distance (position). Each seismic trace associated with a common source-to-receiver distance is first separated into a plurality of frequency band-limited component traces. A time-variant amplitude scale factor (or its equivalent) is generated for each component trace. These scale factors are then applied to the component trace thus compensating for amplitude decay of the component trace. Upon recombination of the component traces a multidimensional amplitude scaled (MIDAS) seismic trace is recovered. The apparatus and method are particularly useful in creating a high-frequency extension of the frequency bandwidth resulting in improved resolution upon further processing or display. The method can be implemented as part of the field procedure or during subsequent computer processing.Type: GrantFiled: August 6, 1979Date of Patent: January 19, 1982Assignee: Standard Oil Company (Indiana)Inventor: Robert C. Lucas