Jakeman / Ridley Modeling Fluctuations in Scattered Waves

Erscheinungsjahr 2010
ISBN: 978-1-4200-1216-3
Verlag: Taylor & Francis
Format: PDF
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)

E-Book, Englisch, 336 Seiten

Reihe: Series in Optics and Optoelectronics

Fluctuations in scattered waves limit the performance of imaging and remote sensing systems that operate on all wavelengths of the electromagnetic spectrum. To better understand these fluctuations, Modeling Fluctuations in Scattered Waves provides a practical guide to the phenomenology, mathematics, and simulation of non-Gaussian noise models and discusses how they can be used to characterize the statistics of scattered waves.

Through their discussion of mathematical models, the authors demonstrate the development of new sensing techniques as well as offer intelligent choices that can be made for system analysis. Using experimental results and numerical simulation, the book illustrates the properties and applications of these models. The first two chapters introduce statistical tools and the properties of Gaussian noise, including results on phase statistics. The following chapters describe Gaussian processes and the random walk model, address multiple scattering effects and propagation through an extended medium, and explore scattering vector waves and polarization fluctuations. Finally, the authors examine the generation of random processes and the simulation of wave propagation.

Although scattered wave fluctuations are sources of information, they can hinder the performance of imaging and remote sensing systems. By providing experimental data and numerical models, this volume aids you in evaluating and improving upon the performance of your own systems.

Zielgruppe

Researchers and professionals in remote sensing, electromagnetics, applied physics, and signal processing

Autoren/Hrsg.

Jakeman, E.

Ridley, K. D.

Fachgebiete

• Naturwissenschaften Physik Elektromagnetismus Optik

Inhaltsverzeichnis

STATISTICAL PRELIMINARIES
Introduction

Random Variables
Transformation of Variables
Wiener-Khinchin Theorem
The Karhunen-Loeve Expansion
Statistical Independence

Characteristic Functions and Generating Functions
Detection

References

THE GAUSSIAN PROCESS
Introduction

Independent Gaussian Variables
Correlated Gaussian Variables
Higher-Order Correlations

Gaussian Processes

Complex Gaussian Processes
Joint Statistical Properties
Properties of the Derivative of a Complex Gaussian Process
Joint Phase Derivative Statistics
References

PROCESSES DERIVED FROM GAUSSIAN NOTES
Introduction

Rice Variables

Rice Processes
Gamma Variables
Gamma Processes

Statistics of the Derivative of a Gamma Process
Compound Variables
Other Commonly Encountered Distributions
References

SCATTERING BY A COLLECTION OF DISCRETE OBJECTS: THE RANDOM WALK MODEL

Introduction

The Incident Wave
Moments of the Field Scattered by a Fixed Number of Small Particles

The Probability Distribution of the Scattered Wave
Variations in Step Length: Illumination by a Gaussian Beam

The Effect of Variations in Step Number
Intensity Correlation

Partially Developed Speckle

References

SCATTERING BY CONTINUOUS MEDIA: PHASE SCREEN MODELS
Introduction

Scattering Geometries

Time-Dependent Scattering
Scattering into the Fresnel Region

Fraunhofer Scattering
Scattering in Non-Gaussian Regimes
Surface Scattering

References

SCATTERING BY SMOOTHLY VARYING PHASE SCREENS
Introduction

"Smooth" Models for the Phase Correlation Function

Qualitative Features of Scattering by Smoothly Varying Phase Screens
Calculation of the Scintillation Index in the Fresnel Region
Predicted Behavior of the Scintillation Index in the Fresnel Region

Higher-Order Statistics in the Fresnel Region

Spatial Coherence Properties in the Fresnel Region
Calculation of the Scintillation Index in the Fraunhofer Region

Predicted Behavior of the Scintillation Index in the Far Field

Higher-Order Statistical Properties in the Far Field
Coherence Properties in the Far Field
Phase Statistics

References

SCATTERING BY FRACTAL PHASE SCREENS
Introduction

Scattering into the Fresnel Region by a Fractal Phase Screen

Scattering into the Fraunhofer Region by a Fractal
Phase Screen

Subfractal Phase Screens

Ray Density Fluctuations beyond a Subfractal Phase Screen

Coherence Properties of the Intensity Beyond a Subfractal Screen
Outer Scale Effects

Scattering into the Fraunhofer Region by a Subfractal Screen

Concluding Remarks
References

OTHER PHASE SCREEN MODELS
Introduction

Scattering by Smoothly Varying Gamma Distributed Phase Screens
Scattering by Fractal Gamma Distributed Phase Screens
Telegraph Wave Phase Screens
Scattering by Telegraph Wave Phase Screens

Phase Statistics

Concluding Remarks
References

PROPAGATION THROUGH EXTENDED INHOMOGENEOUS MEDIA
Introduction

Single Phase Screen Approximation
Power-Law Models for the Refractive Index Spectrum
Multiple Phase Screens

Propagation of Electromagnetic Waves through Turbulence
Intensity Fluctuations
References

MULTIPLE SCATTERING: FLUCTUATIONS IN DOUBLE PASSAGE AND MULTIPATH SCATTERING GEOMETRIES
Introduction

Multiple Scattering in Particulates

Enhanced Backscattering through Continuous Media
A Phase Screen Model for Enhanced Backscattering

Fluctuations in Double Passage Configurations

Multipath Near Surfaces

References

VECTOR SCATTERING: POLARIZATION FLUCTUATIONS
Introduction

The Polarization Characteristics of Gaussian Speckle
Non-Gaussian Polarization Effects in Scattering by Particles
Correlation of Stokes Parameters in Particle Scattering

Scattering from Particles Near an Interface

Polarization Fluctuations: Particles Near an Interface

References

K-DISTRIBUTED NOISE
Introduction

Experimental Evidence

A Population Model for Scatterer Number Fluctuations
Properties of the Scattered Intensity

Related Distributions
Statistical Mechanics

References

MEASUREMENT AND DETECTION
Introduction

Temporal Averaging of a Gamma-Lorentzian Process
Approximations for the Effect of Temporal and Spatial Integration

Averaging Signals with More than One Scale

Enhancement of Fluctuations Caused by Filtering
The Effect of Finite Dynamic Range
The Effect of Finite Measurement Time
Noise in Frequency Demodulation
Detection

Quantum Limited Measurements
References

NUMERICAL TECHNIQUES
Introduction

The Transformation of Random Numbers

Gaussian Random Numbers
The Telegraph Wave
The Gaussian Random Process

Non-Gaussian Processes
Simulation of Wave Propagation

Multiple Phase Screens
References