The study of interference fringes in SAR distributed targets echo simulation

2009 ◽  
Author(s):  
Hanwei Sun ◽  
Tao Zeng
Keyword(s):  
Interference Fringes ◽  
Echo Simulation

Quanitative aspects of electron diffraction using electron holography

1995 ◽  
Vol 53 ◽  
pp. 616-617
Author(s):  
E. Völkl ◽  
L.F. Allard ◽  
B. Frost ◽  
T.A. Nolan
Keyword(s):  
Electron Beam ◽  
Electron Diffraction ◽  
Software Package ◽  
Spatial Coherence ◽  
Electron Holography ◽  
Image Intensity ◽  
Interference Fringes ◽  
Complex Image ◽  
The Difference ◽  
Recorded Image

Off-axis electron holography has the well known ability to preserve the complex image wave within the final, recorded image. This final image described by I(x,y) = I(r) contains contributions from the image intensity of the elastically scattered electrons IeI (r) = |A(r) exp (iΦ(r)) |, the contributions from the inelastically scattered electrons IineI (r), and the complex image wave Ψ = A(r) exp(iΦ(r)) as:(1) I(r) = IeI (r) + Iinel (r) + μ A(r) cos(2π Δk r + Φ(r))where the constant μ describes the contrast of the interference fringes which are related to the spatial coherence of the electron beam, and Φk is the resulting vector of the difference of the wavefront vectors of the two overlaping beams. Using a software package like HoloWorks, the complex image wave Ψ can be extracted.

Silicon Fringe Sample Metrology—A Thickness Measurement Technique

2013 ◽  
Author(s):  
Mark Kimball
Keyword(s):  
Temperature Dependence ◽  
Temperature Coefficient ◽  
Measurement Technique ◽  
Thickness Measurement ◽  
Sample Thickness ◽  
Index Of Refraction ◽  
Interference Fringes ◽  
Noncontact Method ◽  
Thickness Variations

Abstract Silicon’s index of refraction has a strong temperature coefficient. This temperature dependence can be used to aid sample thinning procedures used for backside analysis, by providing a noncontact method of measuring absolute sample thickness. It also can remove slope ambiguity while counting interference fringes (used to determine the direction and magnitude of thickness variations across a sample).

scholarly journals Wavefront dislocations reveal the topology of quasi-1D photonic insulators

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Clément Dutreix ◽  
Matthieu Bellec ◽  
Pierre Delplace ◽  
Fabrice Mortessagne
Keyword(s):  
Local Density ◽  
Topological Defects ◽  
Wave Functions ◽  
Topological Classification ◽  
Local Density Of States ◽  
Topological Phase Transition ◽  
Interference Fringes ◽  
Classical Wave ◽  
Phase Singularities

AbstractPhase singularities appear ubiquitously in wavefields, regardless of the wave equation. Such topological defects can lead to wavefront dislocations, as observed in a humongous number of classical wave experiments. Phase singularities of wave functions are also at the heart of the topological classification of the gapped phases of matter. Despite identical singular features, topological insulators and topological defects in waves remain two distinct fields. Realising 1D microwave insulators, we experimentally observe a wavefront dislocation – a 2D phase singularity – in the local density of states when the systems undergo a topological phase transition. We show theoretically that the change in the number of interference fringes at the transition reveals the topological index that characterises the band topology in the insulator.

scholarly journals Stabilized Interference Fringes on the Retina

Nature ◽  
1956 ◽  
Vol 177 (4505) ◽  
pp. 434-434 ◽  
Author(s):  
R. W. DITCHBURN ◽  
R. M. PRITCHARD
Keyword(s):  
Interference Fringes

High-speed cine recording of real-time holographic interference fringes

1979 ◽  
Vol 31 (2) ◽  
pp. 111-113 ◽  
Author(s):  
T.A. Dullforce ◽  
R.E. Faw
Keyword(s):  
Real Time ◽  
High Speed ◽  
Interference Fringes

Algorithm for computer tracing of interference fringes

1991 ◽  
Vol 30 (13) ◽  
pp. 1624 ◽  
Author(s):  
Sridhar Krishnaswamy
Keyword(s):  
Interference Fringes

Study on Echo Fidelity of Radar Simulator

2014 ◽  
Vol 687-691 ◽  
pp. 1117-1120
Author(s):  
Yin Hui Xu ◽  
Fu Zhi Wang ◽  
Yi Long Liu ◽  
Da Zhi Zeng
Keyword(s):  
Numerical Calculation ◽  
Evaluation System ◽  
Calculation Methods ◽  
Simulation Fidelity ◽  
Research Status ◽  
Similarity Calculation ◽  
Radar Echo ◽  
Echo Simulation ◽  
Radar Simulator ◽  
The Evaluation System

Echo fidelity is an important characteristic of radar simulator and it influences accuracy and reliability of radar test directly. This paper introduces the research status of simulator fidelity and sort out the definition and property of radar echo simulation fidelity. Then we propose the numerical calculation methods for individual indicators, including similarity calculation, dissimilarity computing and interval changes three parts. Finally, on the basis of the evaluation system, we propose two calculation methods for entirety fidelity, they are weighted numerical calculation and umbrella figure methods.

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