MOSFET Ultrasonic Surface‐Wave Detectors for Programmable Matched Filters

1971 ◽  
Vol 19 (3) ◽  
pp. 58-60 ◽  
Author(s):  
L. T. Claiborne ◽  
E. J. Staples ◽  
J. L. Harris ◽  
J. P. Mize
Keyword(s):  
Surface Wave ◽  
Matched Filters

Evaluation of Digitally Coded Acoustic Surface-Wave Matched Filters

1971 ◽  
Vol 18 (1) ◽  
pp. 21-27 ◽  
Author(s):  
W.S. Jones ◽  
C.S. Hartmann ◽  
L.T. Claiborne
Keyword(s):  
Surface Wave ◽  
Matched Filters ◽  
Acoustic Surface Wave

Acoustic surface-wave matched filters using a MOSFET array

1973 ◽  
Vol 61 (8) ◽  
pp. 1165-1167 ◽  
Author(s):  
G.D. O'Clock ◽  
D.A. Gandolfo ◽  
H.J. Bush
Keyword(s):  
Surface Wave ◽  
Matched Filters ◽  
Acoustic Surface Wave

MATCHED FILTER DETECTION OF ELECTROMAGNETIC TRANSIENT REFLECTIONS

Geophysics ◽  
1974 ◽  
Vol 39 (5) ◽  
pp. 683-691 ◽  
Author(s):  
C. S. Clay ◽  
L. L. Greischar ◽  
T. K. Kan
Keyword(s):  
Surface Wave ◽  
Magnetic Permeability ◽  
Matched Filter ◽  
Numerical Models ◽  
Transient Signal ◽  
Matched Filters ◽  
Electromagnetic Transient ◽  
Different Depths ◽  
Aluminum Plates ◽  
Laboratory Models

An electromagnetic transient signal is distorted as it travels in the conducting earth. At vertical incidence, the signal is stretched by a time that is proportional to the magnetic permeability, conductivity, and depth squared. The stretch is a function of the travel distance, and a set of filters can be constructed to match the waveforms of signals which have traveled to different depths. Surface waves travel from the source and can overlap the reflected signals. The reflected signals were estimated by subtracting an estimate of the surface wave and then passing the estimated reflections through a set of matched filters. This method was tested by means of numerical models and laboratory models. The latter were coaxial coils on aluminum plates. In both cases, the matched filters determined the depth of the reflected signals.

Ground roll: Rejection using adaptive phase‐matched filters

Geophysics ◽  
1990 ◽  
Vol 55 (6) ◽  
pp. 776-781 ◽  
Author(s):  
R. B. Herrmann ◽  
D. R. Russell
Keyword(s):  
Surface Wave ◽  
Surface Waves ◽  
Iterative Process ◽  
Spatial Sampling ◽  
Matched Filtering ◽  
Data Sets ◽  
Matched Filters ◽  
Wide Range ◽  
Ground Roll ◽  
Band Pass

The technique of phase‐matched filtering dispersive surface waves is extended to permit an adaptive, iterative process by which the signal itself in a seismic trace designs a filter to remove the surface wave. The technique is robust and well‐behaved and requires the specification of only simple parameters for its operation. The technique is applied to data sets from three regions, representing a wide range in the ratio of surface‐wave noise to exploration signal. The technique works very well with poor data sets and also improves good data sets. Since the technique is applied to individual traces, it works in situations for which f‐k filtering might not be feasible due to poor spatial sampling. The technique is computationally more intensive than recursive digital band‐pass filtering of individual traces, but is less intensive than filtering in the f‐k domain.

A technique for computing surface-wave properties

1975 ◽  
Vol 65 (6) ◽  
pp. 1743-1751
Author(s):  
Robert P. Massé
Keyword(s):  
Surface Wave ◽  
Love Wave ◽  
Velocity Dispersion ◽  
Group Velocity Dispersion ◽  
Earth Structure ◽  
Quality Factors ◽  
Matched Filters ◽  
Wave Parameters ◽  
Wave Properties ◽  
Path Properties

abstract A technique is presented which makes possible the calculation of total-path properties of surface waves which traverse any number of geological regions. Rayleigh- and Love-wave parameters which may be computed with the technique include phase- and group-velocity dispersion, travel time, matched filters, attenuation, quality factors, lateral refraction, and multipathing. The technique has applications both in research of Earth structure and in automatic signal processing.

Exit-surface wave reconstruction using a focal series

1992 ◽  
Vol 50 (2) ◽  
pp. 988-989
Author(s):  
W.J. de Ruijter ◽  
M.R. McCartney ◽  
David J. Smith ◽  
J.K. Weiss
Keyword(s):  
Surface Wave ◽  
Spherical Aberration ◽  
Data Extraction ◽  
High Sensitivity ◽  
Geometric Distortion ◽  
Variation Method ◽  
Objective Lens ◽  
Immediate Reconstruction ◽  
Exit Surface ◽  
Electron Microscopes

Further advances in resolution enhancement of transmission electron microscopes can be expected from digital processing of image data recorded with slow-scan CCD cameras. Image recording with these new cameras is essential because of their high sensitivity, extreme linearity and negligible geometric distortion. Furthermore, digital image acquisition allows for on-line processing which yields virtually immediate reconstruction results. At present, the most promising techniques for exit-surface wave reconstruction are electron holography and the recently proposed focal variation method. The latter method is based on image processing applied to a series of images recorded at equally spaced defocus.Exit-surface wave reconstruction using the focal variation method as proposed by Van Dyck and Op de Beeck proceeds in two stages. First, the complex image wave is retrieved by data extraction from a parabola situated in three-dimensional Fourier space. Then the objective lens spherical aberration, astigmatism and defocus are corrected by simply dividing the image wave by the wave aberration function calculated with the appropriate objective lens aberration coefficients which yields the exit-surface wave.

Surface Wave Utility in Composite Materia] Characterization

1989 ◽  
Vol 1 (1) ◽  
pp. 247-265
Author(s):  
Joseph Rose ◽  
Aleksander Pilarski ◽  
Yimei Huang
Keyword(s):  
Surface Wave

Analysis of focused surface wave transducers

1990 ◽  
Vol 137 (6) ◽  
pp. 467 ◽  
Author(s):  
M. Kirci ◽  
E. Akcakaya
Keyword(s):  
Surface Wave
Sign in / Sign up

Export Citation Format

Share Document