From Fauna to Flames Remote Sensing with Scheimpflug Lidar Malmqvist, Elin 2019 Document Version: Publisher's PDF, also known as Version of record Link to publication Citation for published version (APA): Malmqvist, E. (2019). From Fauna to Flames: Remote Sensing with Scheimpflug Lidar . Department of Physics, Lund University. 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LUND UNIVERSITY PO Box 117 221 00 Lund +46 46-222 00 00 ELIN MALMQVIST ELIN From Fauna to FlamesFrom Sensing Remote with Scheimpflug-Lidar From Fauna to Flames Remote Sensing with Scheimpflug-Lidar ELIN MALMQVIST FACULTY OF ENGINEERING | DEPARTMENT OF PHYSICS | LUND UNIVERSITY Faculty of Engineering Department of Physics Lund University Lund Reports on Combustion Physics, LRCP-218 ISBN 978-91-7753-995-7 (print) 539957 ISBN 978-91-7753-996-4 (pdf) 2019 ISSN 1102-8718 789177 ISRN LUTFD2/TFCP-218-SE 9 From Fauna to Flames Remote Sensing with Scheimpflug-Lidar Elin Malmqvist DOCTORAL DISSERTATION by due permission of the Faculty of Engineering, Lund University, Sweden. To be defended at Rydbergsalen, Fysicum, Professorsgatan 1. 29th March 2019 at 09.15. Faculty opponent Prof. Xinzhao Chu, Department of Aerospace Engineering Sciences, University of Colorado, Boulder, Colorado, USA Organization: Document name: LUND UNIVERSITY Doctoral Dissertation Division of Combustion Physics, Department of Physics P.O Box 118, SE-211 00 Lund, Sweden Date of issue: 2019-02-18 Author: Elin Malmqvist CODEN: LUTFD2/TFCP-218-SE Sponsoring organization Title: From Fauna to Flames Remote Sensing with Scheimpflug-Lidar Abstract This thesis presents applications of the Scheimpflug Lidar (S-Lidar) method. The technique has been applied to combustion diagnostics on a scale of several meters as well as fauna detection and monitoring over distances of kilometers. Lidar or laser radar is a remote sensing technique where backscattering of laser light is detected with range resolution along the direction of the laser beam. It is an established method in e.g. atmospheric sensing where it is used to map and monitor gases and aerosols. In contrast to conventional Lidar, which uses a time-of-flight approach, Scheimpflug Lidar uses imaging to achieve range resolution. The laser beam transmitted from the Lidar system is sharply imaged onto a detector, resulting in range resolution along the sensor. This is done by placing the laser beam, the collection optics and the detector according to two trigonometrical conditions called the Scheimpflug and hinge rules. This kind of Lidar technique enables the use of small, continuous-wave diode lasers and line-array detectors with kHz sampling rates. A general description of the equations governing the achievable measurement range and resolution of S-Lidar are presented. The way the equations relate to the conventional Lidar equation is also discussed as well as the impact of the beam width. The instrumentation and experimental considerations for far range S-Lidar for aerial fauna monitoring are described and some temporally and spatially resolved data from field campaigns in Africa, China and Sweden are presented. A method used to reduce and analyze the large amount of collected data is also described. For the short-range applications, down-scaled versions of the system were developed. These systems are described as well as their applications. The short range system has mostly been used to investigate the potential of the technique to be applied for combustion diagnostics, and results from measurements in flames using both elastic and inelastic optical techniques, such as Rayleigh scattering and two-line atomic fluorescence are presented. A hyperspectral Lidar system aimed at aquatic applications is also presented. Key words: Lidar, Laser radar, Scheimpflug Lidar, Combustion diagnostics, Entomological Lidar Classification system and/or index terms (if any) Supplementary Language: English ISSN and key title: 1102-8718 ISBN (print): 978-91-7753-995-7 ISBN (pdf): 978-91-7753-996-4 Recipient’s notes Number of pages: 212 Price Security classification I, the undersigned, being the copyright owner of the abstract of the above-mentioned dissertation, hereby grant to all reference sources permission to publish and disseminate the abstract of the above-mentioned dissertation. Signature Date 2019-02-18 From Fauna to Flames Remote Sensing with Scheimpflug-Lidar Elin Malmqvist Front cover photo by Elin Malmqvist Back cover photo by Hugh Sturrock (mosquito) and Alexios Matamis (flame) Copyright pp 1-128 Elin Malmqvist Paper I © 2016 IEEE Paper II © 2016 Wiley VCH Paper III © 2017 SPIE Paper IV © 2018 The Royal Society Publishing Paper V © 2018 Optical Society of America Paper VI © 2019 Optical Society of America Faculty of Engineering Department of Physics Lund University Lund Reports on Combustion Physics, LRCP-218 ISBN 978-91-7753-995-7 (print) ISBN 978-91-7753-996-4 (pdf) ISSN 1102-8718 ISRN LUTFD2/TFCP-218-SE Printed in Sweden by Media-Tryck, Lund University Lund 2019 “Light thinks it travels faster than anything but it is wrong. No matter how fast light travels, it finds the darkness has always got there first, and is waiting for it.” Terry Pratchett, Reaper Man “Eternity is a terrible thought. I mean, where's it going to end?” Tom Stoppard, Rosencrantz and Guildenstern Are Dead Content Abstract ........................................................................................................... 9 Populärvetenskaplig sammanfattning ................................................................... 10 List of papers ........................................................................................................ 12 Abbreviations ....................................................................................................... 14 Chapter 1 Introduction ..................................................................................... 15 Remote sensing .................................................................................... 15 Motivation ........................................................................................... 17 1.2.1 Aerial fauna monitoring ........................................................... 18 1.2.2 Combustion diagnostics ........................................................... 19 Chapter 2 Background physics .......................................................................... 21 Light matter interaction ....................................................................... 21 2.1.1 Energy ..................................................................................... 21 2.1.2 Polarization .............................................................................. 22 2.1.3 Scattering ................................................................................. 22 2.1.4 Absorption ............................................................................... 26 2.1.5 Light transport ......................................................................... 28 Signals from insects .............................................................................. 30 2.2.1 Temporal and frequency properties .......................................... 30 2.2.2 Spectral properties ................................................................... 32 2.2.3 Other factors ............................................................................ 36 Signals from flames .............................................................................. 38 2.3.1 Flames ..................................................................................... 38 2.3.2 Optical flame diagnostics ......................................................... 38 Chapter 3 Scheimpflug-Lidar ............................................................................ 41 Scheimpflug and hinge rules ................................................................ 41 Equations of S-Lidar ............................................................................ 45 Chapter 4 Lidar signals ..................................................................................... 51 Conventional Lidar equation ............................................................... 51 Lidar equation for S-Lidar .................................................................... 54 4.2.1 Shape and width of the beam ................................................... 56 4.2.2 Raytracing................................................................................ 57 Chapter 5 Experimental equipment ................................................................... 61 Lasers ..................................................................................................