Coherent component of specular reflection and transmission at a randomly rough two‐fluid interface

1975 ◽  
Vol 58 (2) ◽  
pp. 365-370 ◽  
Author(s):  
William A. Kuperman
Keyword(s):  
Specular Reflection ◽  
Fluid Interface ◽  
Reflection And Transmission ◽  
Coherent Component ◽  
Two Fluid

scholarly journals Untangling the Incoherent and Coherent Scattering Components in GNSS-R and Novel Applications

2020 ◽  
Vol 12 (7) ◽  
pp. 1208 ◽  
Author(s):  
Joan Francesc Munoz-Martin ◽  
Raul Onrubia ◽  
Daniel Pascual ◽  
Hyuk Park ◽  
Adriano Camps ◽  
...  
Keyword(s):  
Antenna Arrays ◽  
Fresnel Zone ◽  
Specular Reflection ◽  
Coherent Scattering ◽  
Global Navigation Satellite Systems ◽  
Dual Band ◽  
Total Power ◽  
Data Set ◽  
Coherent Component ◽  
Leo Satellite

As opposed to monostatic radars where incoherent backscattering dominates, in bistatic radars, such as Global Navigation Satellite Systems Reflectometry (GNSS-R), the forward scattered signals exhibit both an incoherent and a coherent component. Current models assume that either one or the other are dominant, and the calibration and geophysical parameter retrieval (e.g., wind speed, soil moisture, etc.) are developed accordingly. Even the presence of the coherent component of a GNSS reflected signal itself has been a matter of discussion in the last years. In this work, a method developed to separate the leakage of the direct signal in the reflected one is applied to a data set of GNSS-R signals collected over the ocean by the Microwave Interferometer Reflectometer (MIR) instrument, an airborne dual-band (L1/E1 and L5/E5a), multi-constellation (GPS and Galileo) GNSS-R instrument with two 19-elements antenna arrays with 4 beam-steered each. The presented results demonstrate the feasibility of the proposed technique to untangle the coherent and incoherent components from the total power waveform in GNSS reflected signals. This technique allows the processing of these components separately, which increases the calibration accuracy (as today both are mixed and processed together), allowing higher resolution applications since the spatial resolution of the coherent component is determined by the size of the first Fresnel zone (300–500 meters from a LEO satellite), and not by the size of the glistening zone (25 km from a LEO satellite). The identification of the coherent component enhances also the location of the specular reflection point by determining the peak maximum from this coherent component rather than the point of maximum derivative of the incoherent one, which is normally noisy and it is blurred by all the glistening zone contributions.

Transmission and reflection of a real sound beam at a two‐fluid interface

1989 ◽  
Vol 85 (S1) ◽  
pp. S93-S93
Author(s):  
Jacqueline Naze Tjøtta ◽  
Hans‐Christen Salvesen ◽  
Sigve Tjøtta
Keyword(s):  
Fluid Interface ◽  
Sound Beam ◽  
Two Fluid ◽  
Transmission And Reflection

Buoyancy flow at a two-fluid interface in a porous medium: Analytical studies

1988 ◽  
Vol 24 (4) ◽  
pp. 493-506 ◽  
Author(s):  
Göran Hellström ◽  
Chin-Fu Tsang ◽  
Johan Claesson
Keyword(s):  
Porous Medium ◽  
Fluid Interface ◽  
Buoyancy Flow ◽  
Analytical Studies ◽  
Two Fluid

Two-Fluid Electroosmotic Flow in Microchannels

2008 ◽  
Author(s):  
T. N. Wong ◽  
Y. Gao ◽  
C. Wang ◽  
C. Yang ◽  
N. T. Nguyen ◽  
...  
Keyword(s):  
Electric Field ◽  
Applied Electric Field ◽  
Electroosmotic Flow ◽  
Viscosity Ratio ◽  
Experimental Investigations ◽  
Fluid Interface ◽  
Surface Charges ◽  
Interface Position ◽  
Proposed Model ◽  
Two Fluid

This paper presents theoretical and experimental investigations of the pressure-driven two-liquid flow in microchannels with the electroosmosis effect. For a fully developed, steady state, laminar flow of two liquids combined the pressure gradient, electroosmosis and surface charges at the liquid-liquid interface, we have derived analytical solutions that relate the velocity profiles and flow rates to the liquid holdup, the aspect ratio of the microchannel, the viscosity ratio of the two liquids and the externally applied electric field. It was shown that adjusting the externally applied electric field could control the fluid interface position precisely. The prediction from the proposed model compares very well with measured data.

Measurements of liquid film thickness for a droplet at a two-fluid interface

2012 ◽  
Vol 24 (2) ◽  
pp. 022106 ◽  
Author(s):  
G. Oldenziel ◽  
R. Delfos ◽  
J. Westerweel
Keyword(s):  
Film Thickness ◽  
Liquid Film ◽  
Liquid Film Thickness ◽  
Fluid Interface ◽  
Two Fluid
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