Abstract: Conventional migration of short offset seismic data is performed. An interval velocity is obtained using, for example, check shots. An initial model of effective anellipticity parameter as a function of depth is obtained by flattening long offsets within a common image point. From these, interval anellipticity and horizontal velocity are obtained as a function of time. These initial models are used for anisotropic imaging. Any remaining residuals are used to update the interval anellipticity model and the process of migration is repeated until satisfactory results are obtained.

Abstract: The present invention provides for a method of processing mode converted seismic data. The method comprises acquiring seismic data and determining a P-wave velocity model for the seismic data. An S-wave velocity model is determined from the P-wave velocity model. The mode converted seismic data are depth migrated forming CIP mode converted seismic data gathers. Corrected S-wave velocities are determined from near-offset data of the CIP gathers which corrects the depth migrated mode converted seismic data to the P-wave velocity model depth. A correction factor is provided and the iterating with the method quickly converges to a solution. This invention provides an efficient method of updating the shear wave velocity model for prestack depth migration of mode-converted data.

Abstract: The present invention provides for a method of processing mode converted seismic data. The method comprises acquiring seismic data and determining a P-wave velocity model for the seismic data. An S-wave velocity model is determined from the P-wave velocity model. The mode converted seismic data are depth migrated forming CIP mode converted seismic data gathers. Corrected S-wave velocities are determined from near-offset data of the CIP gathers which corrects the depth migrated mode converted seismic data to the P-wave velocity model depth. A correction factor is provided and the iterating with the method quickly converges to a solution. This invention provides an efficient method of updating the shear wave velocity model for prestack depth migration of mode-converted data.

Abstract: Conventional migration of short offset seismic data is performed. An interval velocity is obtained using, for example, check shots. An initial model of effective anellipticity parameter as a function of depth is obtained by flattening long offsets within a common image point. From these, interval anellipticity and horizontal velocity are obtained as a function of time. These initial models are used for anisotropic imaging. Any remaining residuals are used to update the interval anellipticity model and the process of migration is repeated until satisfactory results are obtained.

Abstract: A seismic processing system and method calculates a coherency estimate for a volume of seismic data to detect edges of seismic events. The method includes selecting a portion of the seismic data volume for analysis, selecting a spatial and temporal position in the subset seismic data volume, selecting a subset of seismic samples around seismic position, placing subset seismic sample volume in a matrix, or calculating cosine of instantaneous phase of subset of seismic samples and placing those samples in a matrix, and calculating a coherency estimate for that matrix. The coherency estimate is calculated using either eigenvalue, maximum likelihood or maximum entropy analysis. The coherency estimate is then written to a coherence seismic volume and another spatial and temporal seismic sample position is selected and the process is repeated until all coherence samples are computed for the seismic data volume. Finally, the coherence seismic data volume can be examined and analyzed for useful information.

Abstract: Systems, client computing devices, server computing devices, and methods are disclosed for accessing medical devices, providing remote access to medical devices and/or remotely accessing medical devices. In one exemplary embodiment, client computing devices utilize protocol components that may be obtained from a server computing device via a network to communicate with medical devices in a communications protocol supported by the medical device.

Abstract: A seismic processing system and method calculates a coherency estimate for a volume of seismic data to detect edges of seismic events. The method includes selecting a portion of the seismic data volume for analysis, selecting a spatial and temporal position in the subset seismic data volume, selecting a subset of seismic samples around seismic position, placing subset seismic sample volume in a matrix, or calculating cosine of instantaneous phase of subset of seismic samples and placing those samples in a matrix, and calculating a coherency estimate for that matrix. The coherency estimate is calculated using either eigenvalue, maximum likelihood or maximum entropy analysis. The coherency estimate is then written to a coherence seismic volume and another spatial and temporal seismic sample position is selected and the process is repeated until all coherence samples are computed for the seismic data volume. Finally, the coherence seismic data volume can be examined and analyzed for useful information.

Abstract: A data collection system in which a number of remote terminals (RT) transmit data packets for reception by one or more fixed data collectors (FDC) or a portable data collector (PDC). Each remote terminal (RT) transmits data in two frequency sub-bands to which the fixed and portable data collectors are respectively tuned. Channel capacity is improved in at least the fixed data collector (FDC) sub-band by the use in the remote terminal of minimum shift keying (MSK) encoding and pseudo-random variation of a frequency error applied to the packet transmission frequency for successive packets. In the fixed data collectors dual fast-Fourier transform signal processing enables the interpretation of simultaneous packets with different error frequencies. The use of a single design of remote terminal (RT) in conjunction with portable data collectors (PDC) simplifies system set-up, with the portable collectors providing coverage for those areas where a fixed data collector (FDC) network has yet to be established.

Abstract: A data collection system in which a number of remote terminals (RT) transmit data packets for reception by one or more fixed data collectors (FDC) or a portable data collector (PDC). Each remote terminal (RT) transmits data in two frequency sub-bands to which the fixed and portable data collectors are respectively tuned. Channel capacity is improved in at least the fixed data collector (FDC) sub-band by the use in the remote terminal of minimum shift keying (MSK) encoding and pseudo-random variation of a frequency error applied to the packet transmission frequency for successive packets. In the fixed data collectors dual fast-Fourier transform signal processing enables the interpretation of simultaneous packets with different error frequencies. The use of a single design of remote terminal (RT) in conjunction with portable data collectors (PDC) simplifies system set-up, with the portable collectors providing coverage for those areas where a fixed data collector (FDC) network has yet to be established.

Abstract: A space time gate is selected surrounding a coherent noise to be removed from an array of seismic traces. Signal-plus-noise within the selected gate is extracted from the array of seismic traces. Coherent noise within the gated signal-plus-noise is estimated and subtracted from such gated signal-plus-noise to provide a signal estimate. This signal estimate is restored into the array of seismic traces.

Abstract: Method for removing coherent noise from a series of seismic traces. Each seismic trace included in the series is Fast Fourier Transformed into the frequency domain. For each frequency of the resultant f-x representation, a series of N complex numbers, one corresponding to each trace, is selected. The selected series of complex numbers corresponding to each frequency are processed to produce autoregressive model coefficients from which a polynomial rooting provides complex roots related to wavenumbers and decay constants. Amplitudes and phases for complex non-stationary spatial sinusoids associated with the estimated wavenumbers are then determined. For all frequencies f, the collection of determined wavenumbers, decay constants, amplitudes and phases constitute an f-k representation of the seismic traces.

Abstract: 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.

Abstract: In seismic exploration, seismic reflection from subsurface formations are recorded in the form of a time-distance of seismic traces. This array is transformed into a time-wavenumber domain. Wavenumbers at which coherent noise resides within the time-wavenumber domain are determined. Frequencies corresponding to such wavenumbers are removed by filtering. The frequency-filtered, time-wavenumber domain of seismic traces are then transformed back into a time-distance array of seismic traces.

Abstract: An improved method for cancelling a stationary sinusoid corrupting a data trace is described. The frequency of the corrupting sinusoid is determined precisely and a Wiener-Levinson least squares filter is designed, using a reference sinusoid at precisely the determined frequency and correlated with the corrupted data trace. The filter is applied to the reference trace yielding a noise estimate which can then be subtracted from the data trace.

Abstract: A seismic record is enhanced through trace restoration and extrapolation. A set of traces surrounding a missing trace or adjacent an edge of the seismic record are transformed into the frequency domain using a fast Fourier transform. Each frequency of the resultant x-f representation a series of complex numbers, one corresponding to each trace, is selected. Autoregressive model coefficients are estimated for this complex series using a recursive least squares method. A complex number is estimated for trace restoration and extrapolation from the series of complex numbers and autoregressive coefficients. After all frequency components are thus processed restored or extrapolated traces are obtained by an inverse Fourier transform.

Abstract: Method for restoring seismic data to missing or severely noise contaminated traces included in a seismic section. The seismic section is transformed into a data localizing space and muted to retain only the localized data components of the seismic section. The muted transform space is inverse-transformed into the x-t domain to produce first estimates of the seismic data to be restored. The first estimates of the restored data are substituted for the corresponding traces in the original seismic section. Fully restored traces corresponding to the missing or severly noise contaminated traces are determined from the single estimate of the restored traces.

Abstract: Method of restoring null traces in seismic records. The seismic record is transformed from the x-t domain to the f-k domain by a series of fast Fourier transforms. The f-k transform of the seismic record is filtered to retain only coherent events and the filtered f-k transform is inverse-transformed back to the x-t domain. A first determination of the restored trace corresponding to the null trace is selected and substituted for the null trace. The first determination of the restored trace is used to determine a fully restored trace.