Measurement and Modelling of Light Scattering by Small to Medium Size Parameter Airborne Particles

.......................................................................................................................................................... 4 Acknowledgements .......................................................................................................................................... 5 Chapter 1 Introduction.................................................................................................................................... 7 Chapter 2 The Study of Light and an introduction to Light Scattering theory. .................................................. 9 2.1 The Study of Light ................................................................................................................................ 9 2.1.1 Conflicting Theories....................................................................................................................... 9 2.1.2 An Electromagnetic Phenomenon ................................................................................................. 10 2.1.3 Wave Particle Duality and Quantum Physics ................................................................................ 10 2.2 – Properties of Light ............................................................................................................................. 11 2.2.1 Polarization .................................................................................................................................. 11 2.2.2 The Stokes Parameters ................................................................................................................. 13 2.2.3 Mueller Matrices .......................................................................................................................... 14 2.2.4 The Phase Function ...................................................................................................................... 16 2.2.5 Asymmetry Parameter .................................................................................................................. 17 2.2.6 Degree of Linear Polarization ....................................................................................................... 17 Chapter 3 Geometric Optics ......................................................................................................................... 19 3.1 The Ray Approximation...................................................................................................................... 19 3.1.1 Light Propagation through changing media. .................................................................................. 19 3.1.2 Snell‟s Law .................................................................................................................................. 19 3.1.3 The Fresnel Equations .................................................................................................................. 21 3.2 – Important Light Scattering considerations ........................................................................................... 22 3.2.1 Scattering Cross Sections ............................................................................................................. 22 3.2.2 Size Parameter ............................................................................................................................. 23 Chapter 4 Scattering by Small Particles ........................................................................................................ 25 4.1 Computational Approaches ................................................................................................................. 25 4.1.1 Mie Theory .................................................................................................................................. 25 4.1.2 SVM – Separation of Variables Method........................................................................................ 25 4.1.3 T-Matrix ...................................................................................................................................... 26 4.1.4 DDA Discrete Dipole Approximation .......................................................................................................... 26 4.1.5 FDTD Finite Difference Time Domain ....................................................................................... 26