60 results about "Normal moveout" patented technology

The present invention provides a method and apparatus for arriving at true relative amplitude destretched seismic traces from stretched seismic traces. The method compensates for offset varying reflection interference effects due to normal moveout. Stretch factors β and also input spectra are determined for NMOR stretched seismic traces. Estimates are then made of stretched wavelet spectra from the input spectra. A destretched wavelet spectra is then obtained. Shaping correction factors are determined by taking the ratio of the destretched wavelet spectra to the stretched wavelet spectra and are applied to the input spectra of the stretched traces to arrive at a destretched trace spectra. True relative amplitude scaling factors are computed by taking the ratio of a true relative amplitude property of the destretched wavelet spectra to a corresponding true relative amplitude property of the stretched wavelet spectra. Finally, the true relative amplitude scaling factors are applied to the destretched trace spectra to arrive at true relative amplitude destretched seismic traces.

A method is disclosed for determining interval anisotropic parameters. The method includes determining normal moveout (NMO) velocities and effective anelliptical parameters from seismic data traces. The NMO velocities are processed to obtain interval NMO velocities. The NMO velocities, effective anelliptical parameters and interval NMO velocities are inverted to obtain the interval anisotropic parameters. In one embodiment, the inversion includes damped least squares. In one embodiment, the inversion is preconditioned.

Object images captured by a wide-angle camera are distorted due to the optical effects of the wide-angle lens. The disclosed innovations allow an automatic analysis on the corrected image distinguishing normal movement from an unusual event movement. The analysis is based on Markov Modeling on moving object trajectories and motion angles.

Methods of processing seismic data to remove unwanted noise from meaningful reflection signals are provided for. The methods comprise the steps of assembling seismic data into common geometry gathers in an offset-time domain without correcting the data for normal moveout. The amplitude data are then transformed from the offset-time domain to the time-slowness domain using a Radon transformation. At least of subset of the transformed data is filtered to enhance its coherent noise content and to diminish its primary reflection signal content by defining a slowness high-pass region and, a slowness low-pass region. The low-pass region is defined to enhance the low slowness coherent noise content and to diminish the primary reflection signal content thereof, thereby generating a first subset of said transformed data having enhanced low slowness coherent noise content. The high-pass region is defined to enhance the high slowness coherent noise content and to diminish the primary reflection signal content thereof, thereby generating a second subset of said transformed data having enhanced high slowness coherent noise content. After filtering, the first and second subsets of transformed data are inverse transformed from the time-slowness domain back to the offset-time domain using an inverse Radon transformation to restore the data. The restored signal amplitude data of the first and second subsets of data are then subtracted from the assembled data, thereby enhancing its primary reflection signal content.

In general, the invention relates to an algorithm and process for automated and / or continuous calibration of magnetic sensor, for example such as a sensor installed in a mobile positioning system handset. According to certain aspects, the calibration process can use the normal motion of the handset such that all measurement data from the three orthogonal axes of sensor when exposed to Earth's magnetic field is collected. According to still further aspects, the process includes fitting measurement data to an ellipsoid that characterizes the actual magnetic field measurements from a magnetic sensor, so that anomalies such as hard iron effect, soft iron effect and scale factors can be extracted and / or corrected by comparison to a sphere represented by magnetic field data from a model at the sensor's location.

A method for estimating seismic velocities in vertically transversely isotropic media includes generating an initial estimate of vertical interval velocity and interval normal moveout velocity with respect to depth from seismic data. An initial estimate is generated of a first anisotropy parameter with respect to depth. The first anisotropy parameter is related to the interval normal moveout velocity and the interval vertical velocity. An initial estimate is generated with respect to depth of a second anisotropy parameter. The second anisotropy parameter is related to the first anisotropy parameter and an interval anelliptic parameter. A first tomographic inversion is performed with respect to the interval normal moveout velocity and the second anisotropy parameter at a constant value of the first anisotropy parameter until travel time differentials reach minimum values. Layer depths are adjusted with the initial estimate of vertical interval velocity. Using values of the second anisotropy parameter determined in the first tomographic inversion, a second tomographic inversion is performed of interval normal moveout velocity and the first anisotropy parameter with respect to depth. The adjusted layer depths, interval normal moveout velocities and interval vertical velocities are again adjusted and interval anelliptic parameters are calculated from the second tomographic inversion.

Methods of processing seismic data to remove unwanted noise from meaningful reflection signals are provided for. The methods comprise the steps of assembling seismic data into common geometry gathers in an offset-time domain without correcting the data for normal moveout. The amplitude data are then transformed from the offset-time domain to the time-slowness domain using a limited Radon transformation. That is, the Radon transformation is applied within defined slowness limits pmin and pmax, where pmin is a predetermined minimum slowness and pmax is a predetermined maximum slowness. A corrective filter is then applied to the transformed data enhance the primary reflection signal content of the data and to eliminate unwanted noise events. After filtering, the enhanced signal content is inverse transformed from the time-slowness domain back to the offset-time domain using an inverse Radon transformation.

Method for processing seismic data. In one implementation, the method includes converting a common midpoint (CMP) gather of seismograms into one or more interferogram common midpoint (ICMP) gathers, generating a semblance spectrum for each ICMP gather, stacking the semblance spectrum from each ICMP gather to generate a combined semblance spectrum and deriving a normal moveout (NMO) velocity profile from the combined semblance spectrum.

A walkaway VSP survey is carried out using a receiver array. First arrivals to a plurality of receivers are picked and used to estimate a normal-moveout (NMO) velocity. Using the NMO velocity and vertical velocities estimated from the VSP data, two anisotropy parameters are estimated for each of the layers. The anisotropy parameters may then be used to process surface seismic data to give a stacked image in true depth and for the interpretation purposes. For multi-azimuthal walkaway or 3D VSP data, we determine two VTI parameters ε and δ for multi-azimuth vertical planes. Then we determine five anisotropic interval parameters that describe P-wave kinematics for orthorhombic layers. These orthorhombic parameters may then be used to process surface seismic data to give a stacked image in true depth and for the interpretation purposes.