Prediction of river discharges at confluences based on Entropy theory and surface-velocity measurements

1994 ◽

Author(s):

David E. Montgomery ◽

Robert L. West

Keyword(s):

Spatial Dynamics ◽

Spatial Models ◽

Laser Doppler Vibrometer ◽

Sample Surface ◽

Surface Shape ◽

Surface Velocity ◽

Multiple Point ◽

Range Data ◽

Dynamics Modeling ◽

Velocity Measurements

Abstract Experimental spatial dynamics modeling involves using scanning lasers to sample surface shape and dynamic response of structures in order to verify structural dynamics design intent. Formation of accurate spatial models from laser-based measurements requires that laser position and orientation be registered relative to a fixed coordinate system. A three point direct registration procedure is defined for shape modeling using laser range and mirror deflection angles. Surface velocity measurements with a portable laser Doppler vibrometer (LDV) also require registration, but range information is unavailable. A multiple point indirect registration algorithm for the LDV is described that involves minimizing three nonlinear equations. A simulated laser rangefinder (LRF) was developed for demonstrating three point direct registration. The 3-D geometry of a compressor housing was modeled by combining range data from multiple laser positions. The multiple point indirect registration was applied to 3-D velocity response field reconstruction of a composite plate from velocity measurements scanned at three separate positions.

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Terrain analyses and surface velocity measurements of the Hiorthfjellet rock glacier, Svalbard

Permafrost and Periglacial Processes ◽

10.1002/ppp.467 ◽

2003 ◽

Vol 14 (4) ◽

pp. 359-365 ◽

Cited By ~ 18

Author(s):

Rune S. Ødegård ◽

Ketil Isaksen ◽

Trond Eiken ◽

Johan Ludvig Sollid

Keyword(s):

Surface Velocity ◽

Velocity Measurements ◽

Rock Glacier

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From Surface Flow Velocity Measurements to Discharge Assessment by the Entropy Theory

Water ◽

10.3390/w9020120 ◽

2017 ◽

Vol 9 (2) ◽

pp. 120 ◽

Cited By ~ 16

Author(s):

Tommaso Moramarco ◽

Silvia Barbetta ◽

Angelica Tarpanelli

Keyword(s):

Flow Velocity ◽

Surface Flow ◽

Entropy Theory ◽

Velocity Measurements

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Measurement of Surface Strain-Rate on Taku Glacier, Alaska

Journal of Glaciology ◽

10.3189/s002214300002904x ◽

1964 ◽

Vol 5 (39) ◽

pp. 305-313 ◽

Cited By ~ 1

Author(s):

T. H. Wu ◽

R. W. Christensen

Keyword(s):

Strain Rate ◽

Reasonable Agreement ◽

Stress Condition ◽

Surface Strain ◽

Surface Velocity ◽

Strain Rates ◽

Velocity Measurements ◽

Measured Velocity ◽

Valley Glacier ◽

Measured Strain

AbstractStrain-rate and surface velocity measurements were made on a valley glacier. The measured strain-rates were used to calculate the stress condition and velocity distribution in the glacier. The measured velocity is in reasonable agreement with that calculated from Nye’s plasticity solution.

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Surface velocity and mass balance of Ice Streams D and E, West Antarctica

Journal of Glaciology ◽

10.3189/s0022143000003452 ◽

1996 ◽

Vol 42 (142) ◽

pp. 461-475 ◽

Cited By ~ 4

Author(s):

Robert Bindschadler ◽

Patricia Vornberger ◽

Donald Blankenship ◽

Ted Scambos ◽

Robert Jacobel

Keyword(s):

Mass Balance ◽

Surface Velocity ◽

Random Errors ◽

West Antarctica ◽

Velocity Measurements ◽

Ice Streams ◽

Ice Stream ◽

Data Density ◽

Basal Shear ◽

Collection Methods

AbstractOver 75 000 surface-velocity measurements are extracted from sequential satellite imagery of Ice Streams D and E to reveal a complex pattern of flow not apparent from previous measurements. Horizontal and vertical strain rates, calculated from surface velocity, indicate that the bed experiences larger basal shear where the surface of these ice streams is rougher. Ten airborne-radar profiles and one surface-based radar profile of ice thickness make possible the calculation of mass balance for longitudinal sections of each ice stream. Improved data-collection methods increase data density, substantially reducing random errors in velocity. However, systematic errors continue to limit the ability of the flux-differencing technique used here to resolve local variations in mass balance. Nevertheless, significant local variations in mass balance are revealed, while, overall, Ice Streams D and E are in approximate equilibrium. An earlier estimate of the net mass balance for Ice Stream D is improved.

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Fiber-Based Laser Doppler Velocimeter State of the Technology for Verification and Validation of Surface Velocity Measurements

10.21236/ada576128 ◽

2013 ◽

Author(s):

Mark A. Mentzer

Keyword(s):

Verification And Validation ◽

Laser Doppler ◽

Surface Velocity ◽

Laser Doppler Velocimeter ◽

Velocity Measurements

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Inversion of P-SV seismic data

Geophysics ◽

10.1190/1.1442161 ◽

1986 ◽

Vol 51 (5) ◽

pp. 1056-1068 ◽

Cited By ~ 10

Author(s):

James J. Carazzone

Keyword(s):

Plane Wave ◽

Riccati Equation ◽

Incidence Angle ◽

Surface Velocity ◽

Complex Frequency ◽

Velocity Measurements ◽

Surface Source ◽

Matrix Riccati Equation ◽

Wave Incidence ◽

Plane Wave Incidence

In a layered elastic material, density, shear velocity, and compressional velocity can be found at any depth from broadband surface measurements at two distinct, nonzero, precritical values of plane‐wave incidence angle. Layer‐stripping inversion uses three‐component surface velocity measurements generated by a polarized surface source to determine subsurface properties incrementally. The surface velocity measurements initialize a first‐order, nonlinear, matrix Riccati equation (derived from the elastic wave equation) which takes advantage of an attractive fixed‐point condition in the complex frequency plane to extract subsurface mechanical impedances. Subsurface density and velocities are recovered from the inverted impedances at two or more plane‐wave incidence angles. General properties of the matrix Riccati equation in the complex frequency plane aid in incorporating bandwidth constraints. Inversion of synthetic plane wave data from a piece‐wise continuous model illustrates inversion effects when only a finite bandwidth is available and when different compressional and shear wavelength distance scales are present.

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