Witschas B. Experiments on spontaneous Rayleigh-Brillouin scattering in air: diss. … dr. rer. nat. / Deutsches Zentrum für Luft- und Raumfahrt, Institut Physik der Atmosphäre, Oberpfaffenhofen. - Köln: DLR, Bibliotheks- und Informationswesen, 2011. - iii, 112 p.: ill., graph. - (Forschungsbericht; 2011-17). - Bibliogr.: p.94-105. - ISSN 1434-8454  Место хранения:   061 | Институт оптики атмосферы CO РАН | Томск | Библиотека

Оглавление / Contents

Abstract ........................................................ i 1 Introduction ................................................. 1 2 Light scattering on molecules ................................ 5 2.1 Physical description of different molecular light scattering mechanisms ................................... 5 2.1.1 Rayleigh scattering .............................. 7 2.1.2 Raman scattering ................................. 9 2.1.3 The Cabannes line (Rayleigh-Brillouin scattering) ..................................... 11 2.2 Comparison of the different spectral components of molecular scattered light .............................. 15 2.3 The Cabannes line and the Tenti S6 model ............... 18 2.3.1 Derivation of the Tenti S6 model ................ 21 2.3.2 Physical limitations of the Tenti S6 model ...... 24 2.3.3 Tenti S6 model sensitivity to gas transport parameter uncertainties ......................... 29 2.4 Summary ................................................ 31 3 Investigation of spontaneous Rayleigh-Brillouin scattering of ultraviolet light in N2, dry and humid air in laboratory experiments ...................................... 32 3.1 Introduction ........................................... 32 3.2 Experimental details ................................... 36 3.2.1 Setup ........................................... 36 3.2.2 The instrument function ......................... 39 3.2.3 Investigation of stray light .................... 40 3.2.4 Measurement procedure ........................... 42 3.2.5 Frequency calibration and spectral averaging .... 44 3.2.6 Comparison of measurement data to the Tenti S6 model ........................................... 45 3.3 Discussion of experimental results ..................... 49 3.3.1 Determination of the bulk viscosity ............ 49 3.3.2 Rayleigh-Brillouin spectra measured in N2 and air ............................................. 52 3.3.3 Rayleigh-Brillouin spectra measured in air at atmospheric conditions .......................... 54 3.3.4 Influence of water vapor to the Rayleigh- Brillouin line shape ............................ 56 3.4 Summary ................................................ 58 4 Investigation of spontaneous Rayleigh Brillouin scattering in the atmosphere ........................................... 60 4.1 Introduction ........................................... 60 4.2 Experimental details ................................... 63 4.2.1 The environmental research station Schneefernerhaus ................................ 63 4.2.2 The A2D Doppler Wind Lidar ...................... 64 4.2.3 Instrument function of the plane-parallel Fabry-Perot interferometer ...................... 69 4.2.4 Measurement principle ........................... 76 4.2.5 Data analysis procedure ......................... 78 4.3 Discussion of experimental results ..................... 82 4.4 Summary ................................................ 88 5 Conclusion and outlook ...................................... 89 Bibliography ................................................... 94 A Appendix ................................................... 106 A.l Analytical model for spontaneous Rayleigh-Brillouin line shapes in air .................................... 106 A.2 Synoptic tables ....................................... 109 A.3 Abbreviations and symbols ............................. 1ll B Acknowledgments ............................................ 113 C Curriculum vitae ........................................... 114 D Own publications ........................................... 115