Proceedings of the 30th International Laser Radar Conference (Springer Atmospheric Sciences)

This volume presents papers from the biennial International Laser Radar Conference (ILRC), the world’s leading event in the field of atmospheric research using lidar. With growing environmental concerns to address such as air quality deterioration, stratospheric ozone depletion, extreme weather events, and changing climate, the lidar technique has never been as critical as it is today to monitor, alert, and help solve current and emerging problems of this century. The 30th occurrence of the ILRC unveils many of the newest results and discoveries in atmospheric science and laser remote sensing technology. The 30th ILRC conference program included all contemporary ILRC themes, leveraging on both the past events’ legacy and the latest advances in lidar technologies and scientific discoveries, with participation by young scientists particularly encouraged. This proceedings volume includes a compilation of cutting-edge research on the following themes: new lidar techniques and methodologies; measurement of clouds and aerosol properties; atmospheric temperature, wind, turbulence, and waves; atmospheric boundary layer processes and their role in air quality and climate; greenhouse gases, tracers, and transport in the free troposphere and above; the upper mesosphere and lower thermosphere; synergistic use of multiple instruments and techniques, networks and campaigns; model validation and data assimilation using lidar measurements; space-borne lidar missions, instruments and science; ocean lidar instrumentation, techniques, and retrievals; and past, present and future synergy of heterodyne and direct detection lidar applications. In addition, special sessions celebrated 50 years of lidar atmospheric observations since the first ILRC, comprising review talks followed by a plenary discussion on anticipated future directions. Preface Organization Organizing Committee Program Committee Reviewers Contents Part I Emerging Lidar Techniques, Methodologies, and Discoveries 1 Rotational Raman Scattering Through Narrow-Band Interference Filters: Investigating Uncertainties Using a New Rayleigh Scattering Code Developed Within ACTRIS 1.1 Introduction 1.2 Presenting ARC: Algorithm for Raman Calculations 1.2.1 Isotropic Scattering of Light 1.2.2 Anisotropic Scattering of Light 1.2.3 Backscattering Cross-Sections of the Rotational Raman Lines 1.2.4 Molecular Linear Depolarization Ratios 1.3 Applications 1.3.1 Uncertainties Due to the Atmospheric Composition and Temperature 1.3.2 Uncertainties in the MLDR Due to the Transmission Function of the IFF 1.4 Summary References 2 Performance of Low-Cost, Diode-Based HSRL System with Simplified Optical Setup 2.1 Introduction 2.2 Optical Setup 2.2.1 Locking 2.3 Performance 2.4 Conclusion References 3 Sensitivity Study on the Performance of the Single Calculus Chain Aerosol Layering Module 3.1 Methodology 3.2 Results 3.2.1 Sensitivity Study of the WCT Dilation Value 3.2.2 Stability of the Intensive Properties Within the Layer Boundaries 3.3 Conclusions References 4 Particle Complex Refractive Index from 3β + 2α HSRL/Raman Lidar Measurements: Conditions of Accurate Retrieval, Uncertainties, and Constraints Provided by Information About RH 4.1 Introduction 4.2 Methodology 4.3 Numerical Simulations 4.4 Case Study 4.5 Conclusion References 5 Field Testing of a Diode-Laser-Based MicroPulse Differential Absorption Lidar System to Measure Atmospheric Thermodynamic Variables 5.1 Introduction 5.2 MicroPulse DIAL Hardware 5.3 Field Testing 5.4 Summary References 6 Semiconductor Lidar for Quantitative Atmospheric Profiling 6.1 Introduction 6.2 Instrument Architecture 6.2.1 Recent Advances 6.3 Initial Test Results 6.4 Summary References 7 Atomic Barium Vapor Filter for Ultraviolet High-Spectral-Resolution Temperature LiDAR 7.1 Introduction 7.2 Filter Characterization Measurements 7.3 Temperature LiDAR Application 7.4 Conclusions References 8 Future Lidars for Cutting-Edge Sciences in Ionosphere-Thermosphere-Mesosphere-Stratosphere Physics and Space-Atmosphere Coupling 8.1 Introduction 8.2 Stunning Science Discoveries Enabled by Lidars 8.3 Future Lidar Directions and Key Lidar Technologies 8.4 Conclusions References 9 Polarization Lidar for Monitoring Dust Particle Orientation: First Measurements 9.1 Introduction 9.2 WALL-E Lidar 9.3 First Measurements of Oriented Particles 9.3.1 Oriented Rain Particles 9.3.2 Oriented Ice Particles 9.3.3 Oriented Dust or Drizzle Particles 9.4 Summary and Future Steps References 10 Dust Flow Distribution Measurement by Low Coherence Doppler Lidar 10.1 Introduction 10.2 Low-Coherence Doppler Lidar 10.3 Laboratory-Based Dust Speed Measurement 10.4 Results and Discussion 10.5 Conclusions References 11 A Multiwavelength LED Lidar for Near-Ground Atmospheric Monitoring 11.1 Introduction 11.2 Instruments and Methodology 11.3 Results and Discussion 11.4 Conclusion References 12 Development of Low-Cost High Spectral Resolution Lidar Using Compact Multimode Laser for Air Quality Measurement 12.1 Introduction 12.2 Lidar System 12.3 Aerosol Profile Measurement 12.4 Conclusions References 13 Deep-Learning-Based Convective Boundary Layer Determination for Aerosol and Wind Profiles Observed by Wind LiDAR 13.1 Introduction 13.2 Methodology 13.2.1 Doppler LiDAR 13.2.2 Deep Learning Model (Stacked Hourglass Network) 13.3 Results 13.3.1 Conclusions References 14 LITES: Laboratory Investigations of Atmospheric Aerosol Composition by Raman-Scattering and Fluorescence Spectra 14.1 Introduction 14.2 Equipment and Methods 14.3 Results and Discussion 14.4 Conclusions References 15 Performance Simulation of a Raman Lidar for the Retrieval of CO2 Atmospheric Profiles 15.1 Introduction 15.2 The Raman Lidar Simulator 15.3 Results 15.4 Conclusions References 16 All Fiber Free-Running Dual-Comb Ranging System 16.1 Background 16.2 Principle 16.3 Experiment Setup 16.4 Experiment Results 16.5 Conclusion References 17 gPCE Uncertainty Quantification Modeling of LiDAR for Bathymetric and Earth Science Applications 17.1 Motivation 17.2 Generalized Polynomial Chaos Expansion 17.3 Preliminary Topographic LiDAR gPCE Results 17.4 Concluding Remarks References 18 When Can Poisson Random Variables Be Approximated as Gaussian? 18.1 Introduction 18.2 Gaussian Approximation 18.3 Simulations 18.4 Conclusion References 19 Enhancing the Performance of the MicroPulse DIAL Through Poisson Total Variation Signal Processing 19.1 Introduction 19.2 Poisson Total Variation 19.3 DIAL Retrievals 19.3.1 Water Vapor 19.3.2 Temperature 19.4 TCSPC Processing References 20 Development of MicroPulse Lidar Network (MPLNET) Level 3 Satellite Validation Products in Advance of the EarthCARE Mission 20.1 Introduction 20.1.1 Background 20.1.2 MicroPulse Lidar Network (MPLNET) 20.1.3 EarthCARE (Earth Clouds, Aerosols, and Radiation Explorer) 20.2 MPLNET Level 3 Products for Satellite Validation References 21 Three-Dimensional Point Cloud Classification Using Drone-Based Scanning LIDAR and Signal Diversity 21.1 Background and Motivation 21.2 Lidar Signal Diversity 21.2.1 Point Density and Polarization 21.2.2 Physical Attribute Classification 21.3 Bathymetric Applications References 22 Design and Validation of an Elastic Lidar Simulator for Testing Potential New Systems for Aerosol Typing 22.1 Introduction 22.2 Theory and Methodology 22.2.1 The Single Scattering Lidar Equation 22.2.2 Simulator Framework 22.3 Results and Discussion 22.3.1 Validation of the Simulator 22.3.2 Effect of Molecular Backscatter Profile Derivation 22.3.3 SNR Dependency on System Parameters 22.4 Conclusions and Further Work References 23 Performance of Pulsed Wind Lidar Based on Optical Hybrid 23.1 Introduction 23.2 Pulsed Wind Lidar System 23.3 Signals and Their Processing 23.4 Discussion and Conclusion References 24 Demonstrating Capabilities of Multiple-Beam Airborne Doppler Lidar Using a LES-Based Simulator 24.1 Introduction 24.2 ADL Simulator 24.3 Results 24.3.1 Mean Wind Speed Retrieval Quality 24.3.2 Dependence on Elevation Angle 24.4 Additional Capabilities of Multiple Beam System 24.5 Conclusions References 25 All-Solid State Iron Resonance Lidar for Measurement of Temperature and Winds in the Upper Mesosphere and Lower Thermosphere 25.1 Introduction 25.1.1 Radar and Lidar Studies at HAARP 25.1.2 Iron Resonance Lidar 25.2 Iron Resonance Wind-Temperature Lidar 25.2.1 Spectroscopy of Nd:YAG 25.2.2 Prototype Nd:YAG-Based Iron Lidar 25.2.3 New Nd:YAG Lidar References 26 Improved Remote Operation Capabilities for the NASA GSFC Tropospheric Ozone Lidar for Routine Ozone Profiling for Satellite Evaluation 26.1 Introduction 26.2 Hardware Improvements 26.2.1 Hatch 26.2.2 Power Distribution Units 26.2.3 Power Meters/Flip Mounts 26.2.4 Temperature Probes/Pressure Sensor 26.3 Automation Steps 26.3.1 Diagnostic Program 26.3.2 Surface Datalogger 26.4 Improved Data Collection References 27 A Wind, Temperature, H2O, and CO2 Scanning Lidar Mobile Observatory for a 3D Thermodynamic View of the Atmosphere 27.1 Introduction 27.2 Instrumental Setup 27.2.1 3D Lidar Observatory 27.2.2 TERA: Temperature and Water Vapor Raman Lidar 27.2.3 COWI: CO2 and Wind Lidar, Doppler, and DIAL 27.3 Measurements and Performances 27.3.1 3D Lidar Sensing 27.3.2 Potential Temperature and Specific Humidity Gradients and Fluxes 27.3.3 Some Insight in CO2 DIAL Measurements References 28 Low-Cost and Lightweight Hyperspectral Lidar for Mapping Vegetation Fluorescence 28.1 Introduction 28.2 Instrumentation 28.3 Experiment 28.4 Data Processing and Results 28.5 Discussion, Summary, and Perspectives References 29 SO2 Plumes Observation with LMOL: Theory, Modeling, and Validation 29.1 Introduction 29.1.1 LMOL 29.1.2 The Hampton Steam Plant 29.2 Retrieval Theory 29.3 Simulation 29.4 Observation 29.5 Future Work References 30 Possible Use of Iodine Absorption/Fluorescence Cell in High-Spectral-Resolution Lidar 30.1 Introduction 30.2 Concept of the Iodine Fluorescence Detector 30.3 Methods for Improving the Detector Performance 30.4 Conclusion References Part II Atmospheric Clouds and Aerosol Properties 31 Ten Years of Interdisciplinary Lidar Applications at SCNU, Guangzhou 31.1 Introduction 31.2 Pulsed Lidar Remote Sensing 31.3 CW Lidar Remote Sensing of Fauna 31.4 Drone-Based CW Fluorescence Lidar Studies 31.5 Short-Range Active Remote Sensing 31.6 Enhanced Vision Through Scattering Modulation References 32 Feasibility Studies of the Dual-Polarization Imaging Lidar Based on the Division-of-Focal-Plane Scheme for Atmospheric Remote Sensing 32.1 Introduction 32.2 The Experimental Setup 32.3 Atmospheric Aerosol Measurements 32.4 Conclusion References 33 An Algorithm to Retrieve Aerosol Optical Properties from ATLID and MSI Measurements 33.1 Introduction 33.2 Product 33.3 Algorithm 33.3.1 Feature Mask 33.3.2 Particle Optical Properties 33.3.3 Aerosol Types 33.3.4 Planetary Boundary Layer 33.4 Summary References 34 Observation of Polar Stratospheric Clouds at Dome C, Antarctica. 34.1 LiDAR Observations of Polar Stratospheric Clouds (PSCs) in Antarctica 34.2 PSC Classification 34.3 Comparison of Ground-Based LiDAR Data with CALIOP Data References 35 Laboratory Evaluation of the Lidar Particle Depolarization Ratio (PDR) of Sulfates, Soot, and Mineral Dust at 180.0 Lidar Backscattering Angle 35.1 Introduction 35.2 The Laboratory Aerosol Pi-Polarimeter [1] 35.3 Laboratory Evaluation of Mineral Dust Lidar PDR [1, 9] 35.4 Laboratory Evaluation of Soot Particle Lidar PDR [2, 3] 35.5 Conclusion and Outlooks References 36 Fresh Biomass Burning Aerosol Observed in Potenza with Multiwavelength Raman Lidar and Sun Photometer 36.1 Introduction 36.2 Instruments 36.3 Case of Study of 14 August 2021 36.3.1 Measurements References 37 Aerosol Studies with Spectrometric Fluorescence and Raman Lidar 37.1 Introduction 37.2 Instrument and Methods 37.3 Measurement Examples References 38 Continuous Observations of Aerosol-Weather Relationship from a Horizontal Lidar to Simulate Monitoring of Radioactive Dust in Fukushima, Japan 38.1 Introduction 38.2 Horizontal Lidar and Weather Instruments 38.3 Methodology 38.4 Results and Discussion 38.4.1 Relationship of Extinction Coefficient and Depolarization Ratio with Weather Data 38.5 Conclusion References 39 Statistical Simulation of Laser Pulse Propagation Through Cirrus-Cloudy Atmosphere 39.1 Introduction 39.1.1 The Current State of Problem-Solving 39.1.2 Statement of the Problem 39.2 The Monte Carlo Model 39.2.1 General Description 39.2.2 Statistical Convergence 39.3 Results 39.3.1 Effects of Multiple Scattering 39.3.2 Echo Signal in Cirrus-Cloudy Atmosphere 39.4 Conclusion References 40 Aerosol Spatial Distribution Observed by a Mobile Vehicle Lidar with Optics for Near-Range Detection 40.1 Introduction 40.2 Methodology 40.2.1 System Setup of a Mobile Vehicle Lidar 40.2.2 Data Analysis 40.3 Results 40.3.1 Vertical Observation in Urban Areas 40.3.2 Horizontal Observation Over Farmland 40.4 Summary References 41 Cloud Base Height Correlation Between a Co-located Micro-Pulse LiDAR and a Lufft CHM15k Ceilometer 41.1 Introduction 41.2 Methodology 41.2.1 Comparison of the Instrument-Specific Cloud-Base Detection Algorithms 41.2.2 The Gradient-Based Detection (GBD) Algorithm 41.3 Summary and Conclusions References 42 Comparison of Local and Transregional Atmospheric Particles over the Urmia Lake in Northwest Iran, Using a Polarization Lidar Recordings 42.1 Introduction 42.2 Data Set and Measurements 42.3 Results and Discussions 42.3.1 Case Studies 42.3.2 Overall Behavior of Atmospheric Particles 42.4 Conclusions References 43 Properties of Polar Stratospheric Clouds over the European Arctic from Ground-Based Lidar 43.1 Introduction 43.2 Observations 43.3 Evaluation of the Lidar Data 43.4 Inversion of Microphysical Properties 43.5 Conclusions References 44 Two Decades Analysis of Cirrus Cloud Radiative Effects by LiDAR Observations in the Frame of NASA MPLNET LiDAR Network 44.1 Introduction 44.2 Methodology 44.3 Results References 45 Temporal Variability of the Aerosol Properties Using a Cimel Sun/Lunar Photometer over Thessaloniki, Greece: Synergy with the Upgraded THELISYS Lidar System 45.1 Study Site and Instrumentation 45.1.1 The Thessaloniki Lidar System (THELISYS) 45.1.2 CIMEL Sun/Lunar Photometer (AERONET) 45.2 Data and Methodology 45.3 Results 45.3.1 Case Study: 20 October 2021 45.3.2 Variability of AERONET AOD and Comparison with THELISYS 45.4 Conclusions References 46 Long-Term Changes of Optical Properties of Mineral Dust and Its Mixtures Derived from Raman Polarization Water Vapor Lidar in Central Europe 46.1 Introduction 46.2 Methodology 46.3 Results 46.4 Conclusions References 47 Planetary Boundary Layer Height Measurements Using MicroPulse DIAL 47.1 Introduction 47.2 Instrumentation 47.3 Methods 47.4 HSRL PBLH Retrievals 47.5 WV-DIAL PBLH Retrievals 47.6 Conclusion References Part III Atmospheric Temperature, Water Vapor, Wind, Turbulence, and Waves 48 Performance Modeling of a Diode Laser-Based Direct Detection Doppler Lidar 48.1 Introduction 48.2 Instrument Overview 48.3 Wind Velocity Retrieval 48.4 Performance Estimates 48.5 Conclusions References 49 Observation of Water Vapor Profiles by Raman Lidar with 266-nm Laser in Tokyo 49.1 Introduction 49.2 Methodology 49.2.1 Raman Lidar System 49.2.2 Retrieval of Water Vapor Profiles 49.3 Results and Discussions 49.4 Conclusions References 50 A 355-nm Direct-Detection Doppler Wind Lidar for Vertical Atmospheric Motion 50.1 Introduction 50.2 Lidar Instrument 50.3 Results 50.4 Summary References 51 Aircraft Wake Vortex Recognition and Classification Based on Coherent Doppler Lidar and Convolutional Neural Networks 51.1 Introduction 51.2 Experiments and Data 51.3 Methodology 51.3.1 Establishment of Data Set 51.3.2 Convolutional Neural Network Models 51.4 Results and Discussion 51.5 Conclusion References 52 MicroPulse Differential Absorption LiDAR for Temperature Retrieval in the Lower Troposphere 52.1 Introduction 52.2 Temperature Retrieval 52.3 Results 52.4 Summary References 53 Long-Term Calibration of a Pure Rotational Raman LiDAR for Temperature Measurements Using Radiosondes and Solar Background 53.1 Introduction 53.2 Measurements and Methodology 53.2.1 Raman LiDAR for Meteorological Observations (RALMO) 53.3 Calibration of Temperature Measurements 53.3.1 External Calibration for Temperature 53.3.2 Internal Calibration for Temperature: The Solar Background Method 53.4 Results 53.4.1 Conclusions References 54 Powerful Raman LiDAR for Water Vapor in the Free Troposphere and Lower Stratosphere as well as Temperature in the Stratosphere and Mesosphere 54.1 Introduction 54.2 System Description 54.3 Results for Water Vapor and Temperature 54.4 Conclusions References 55 Observation of Rainfall Velocity and Raindrop Size Using Power Spectrum of Coherent Doppler Lidar 55.1 Introduction 55.2 Experiments 55.3 Results 55.3.1 Lidar Power Spectrum Analysis During Rain Events 55.3.2 Rain Identification 55.3.3 Estimation of Raindrop Size Distribution 55.4 Conclusions and Discussions References 56 Comparison of Lower Tropospheric Water Vapor Vertical Distribution Measured with Raman Lidar and DIAL and The Impact of Data Assimilation in Numerical Weather Prediction Model 56.1 Introduction 56.2 MRI Raman Lidar (MRI-RL) and Vaisala-DIAL 56.2.1 MRI-RL 56.2.2 Vaisala-DIAL 56.3 Results of the Measurements and Comparison with Radiosonde 56.4 Data Assimilation Experiment of Lidar Data in the Mesoscale Model References 57 Temperature Variations in the Middle Atmosphere Studied with Rayleigh Lidar at Haikou (19.9N, 110.3E) 57.1 Introduction 57.2 Instrumentation and Analysis Methodology 57.3 Results and Discussions 57.3.1 Annual, Semiannual, and Seasonal Variations of Temperature in the Middle Atmosphere 57.3.2 Interannual Variation of Stratopause Temperature 57.4 Conclusion References 58 Convective Boundary Layer Sensible and Latent Heat Flux Lidar Observations and Towards New Model Parametrisations 58.1 Introduction 58.2 Instrumental Deployment 58.3 Lidar Eddy-Covariance Flux 58.4 First Insight in Gradient and Flux Relationships in CBL Entrainment Layer 58.4.1 Theoretical Considerations 58.4.2 Assessment of Entrainment Flux Parametrisation with Observations References Part IV Atmospheric Boundary Layer Processes 59 Observation of Structure of Marine Atmospheric Boundary Layer by Ceilometer Over the Kuroshio Current 59.1 Introduction 59.2 Observations and Methodology 59.3 MABL Structure Over the Kuroshio 59.4 Summary References 60 ABL Height Different Estimation by Lidar in the Frame of HyMeX SOP1 Campaign 60.1 Introduction 60.2 Dataset and Method Description 60.3 Conclusion References 61 Temporal Evolution of Wavelength and Orientation of Atmospheric Canopy Waves 61.1 Introduction 61.2 Algorithm 61.3 Results 61.4 Conclusions References 62 Assessment of Planetary Boundary Layer Height Variations Over a Mountain Region in Western Himalayas 62.1 Introduction 62.2 Study Site and Instrumentation 62.2.1 Study Site 62.2.2 Instrumentation 62.3 Methodology 62.4 Results and Discussions 62.5 Conclusions References 63 Analysis of Updraft Characteristics from an Airborne Micro-pulsed Doppler Lidar During FIREX-AQ 63.1 Introduction 63.2 Instrumentation 63.2.1 Micro-Joule Class Pulsed Coherent Doppler Lidar 63.2.2 NightFox Ham-Cam 63.3 Results 63.3.1 Isolating Updrafts in Wildfire Plumes 63.3.2 General Characteristics 63.3.3 Counter-Rotating Vortex (CRV) Structures and Their Interaction with Updrafts 63.4 Summary and Future Work References 64 Diurnal Variability of MLH and Ozone in NYC Urban and Coastal Area from an Integrated Observation During LISTOS 2018 64.1 Introduction 64.2 Methodology and Observation 64.3 Result and Discussion 64.3.1 Diurnal and Spatial Variation of MLH in the NYC Urban and Coastal Area 64.3.2 Comparison of O3 and MLH Diurnal Variation 64.3.3 Model Product Validation for O3 and PBLH 64.4 Conclusion References 65 Boundary Layer Dynamics, Aerosol Composition, and Air Quality in the Urban Background of Stuttgart in Winter 65.1 Introduction 65.2 Method 65.3 Results and Discussion 65.3.1 Ground-Level Aerosol Optical Properties Characterized by In Situ and Remote-Sensing Measurements 65.3.2 Case Study on Evolution of Boundary Layer and Its Impact on Surface-Level Aerosol 65.4 Conclusions References Part V Greenhouse Gases, Tracers, and Transport in the Free Troposphere and Above 66 DIAL Ozone Measurement Capability Added to NASA's HSRL-2 Instrument Demonstrates Tropospheric Ozone Variability Over Houston Area 66.1 Introduction 66.1.1 Rationale 66.1.2 Instrument Information 66.1.3 Sampling Strategy 66.2 Data Products 66.2.1 Ozone 66.2.2 Aerosol Products 66.3 Aerosol Corrections for DIAL Ozone Measurements References 67 Trajectory Analysis of CO2 Concentration Increase Events in the Nocturnal Atmospheric Boundary Layer Observed by the Differential Absorption Lidar 67.1 Introduction 67.2 CO2-DIAL System 67.3 CO2 Measurement and Trajectory Analysis 67.4 Conclusion References 68 Efficiency Assessment of Single-Cell Raman Gas Mixture for DIAL Ozone Lidar 68.1 Introduction 68.2 SRS Technique 68.3 Experimental Setup 68.4 Results and Discussion 68.5 Conclusion References 69 A Compact Raman Lidar for Atmospheric CO2 and Thermodynamic Profiling: The System CONCERNING 69.1 Introduction References 70 Characterization of Recent Aerosol Events Occurring in the Subtropical North Atlantic Region Using a CIMEL CE376 GPN Micro-LiDAR 70.1 Introduction 70.2 Specifications of the CE376 and Ancillary Information 70.2.1 Specifications of the CE376 70.2.2 Ancillary Information 70.3 Characterization of Dust and Volcanic Aerosol Properties Using the CE376 70.4 Conclusions References 71 Tropospheric Ozone Differential Absorption Lidar (DIAL) Development at New York City 71.1 Introduction 71.2 System Description 71.3 Methodology 71.3.1 Ozone DIAL Equation 71.3.2 Ozone Retrieval 71.4 Observation Results 71.5 Conclusion References Part VI Measurements in the Stratosphere, Mesosphere and Thermosphere 72 Accounting for the Polarizing Effects Introduced from Nonideal Quarter-Wave Plates in Lidar Measurements of the Circular Depolarization Ratio 72.1 Introduction 72.2 The EVE Lidar 72.3 Methodology 72.3.1 The General Case 72.3.2 Solving for a Nonideal QWP 72.4 Application and Results 72.5 Summary References 73 Investigating the Geometrical and Optical Properties of the Persistent Stratospheric Aerosol Layer Observed over Thessaloniki, Greece, During 2019 73.1 Introduction 73.1.1 Possible Sources of the Stratospheric Layer 73.1.2 Instrumentation and Dataset 73.2 Results: Overview of the Stratospheric Layer 73.2.1 Geometrical and Optical Properties of the Volcanic Aerosol Layer in the Stratosphere on July 25, 2019 73.3 Conclusion References 74 New Lidar Data Processing Techniques for Improving the Detection Range and Accuracy of Atmospheric Gravity Wave Measurements 74.1 Introduction 74.2 Methodology 74.2.1 Noise-Variance Subtraction (VS) 74.2.2 Spectral Proportion (SP) Method 74.2.3 Interleaved Method 74.2.4 Uncertainty Analysis: Accuracy 74.3 Conclusions References 75 Extending the Useful Range of Fluorescence LIDAR Data by Applying the Layered Binning Technique 75.1 Introduction 75.2 Methodology 75.3 Results 75.4 Conclusion References Part VII Measurement Techniques and Observations of Ocean Properties 76 Interaction Between Sea Wave and Surface Atmosphere by Shallow Angle LED Lidar 76.1 Introduction 76.2 LED Mini-Lidar for Shallow Angle Sea Wave Measurement 76.3 Observations 76.4 Discussions 76.5 Summary References 77 First Results of the COLOR (CDOM-Proxy Retrieval from aeOLus ObseRvations) Project 77.1 Introduction 77.2 COLOR Approach 77.3 Results 77.4 Summary and Conclusions References 78 Dual Wavelength Heterodyne LDA for Velocity and Size Distribution Measurements in Ocean Water Flows 78.1 Introduction 78.2 Laser Doppler Current Probe System 78.3 Results and Discussion 78.3.1 Velocity Profile Measurements of Subsurface Current 78.3.2 Size Measurement of the Micro-Scale Suspended Particles 78.4 Conclusion References Part VIII Space-Borne Lidar Missions, Instruments and Science 79 Mitigation Strategy for the Impact of Low Energy Laser Pulses in CALIOP Calibration and Level 2 Retrievals 79.1 Introduction 79.2 Low Energy Mitigation (LEM) Algorithm 79.3 LEM Application to Calibration 79.4 LEM Application to Level 2 Feature Detection 79.5 Conclusion and Implementation Plan References 80 Introducing the Cloud Aerosol Lidar for Global Scale Observations of the Ocean-Land-Atmosphere System: CALIGOLA 80.1 Introduction References 81 An Overview of the NASA Atmosphere Observing System Inclined Mission (AOS-I) and the Role of Backscatter Lidar 81.1 Introduction 81.1.1 AOS-I Science and Applications 81.2 The ALICAT Instrument 81.3 ALICAT Contributions to AOS-I Science and Synergy References 82 Proposal for the Space-Borne Integrated Path Differential Absorption (IPDA) Lidar for Lower Tropospheric Water Vapor Observations 82.1 Introduction 82.2 Space-Borne Water Vapor DIAL 82.3 IPDA DIAL 82.4 Conclusion References 83 Assimilation of Aerosol Observations from the Future Spaceborne Lidar Onboard the AOS Mission into the MOCAGE Chemistry: Transport Model 83.1 Introduction 83.2 Method 83.2.1 OSSE 83.2.2 Nature Run and Control Runs 83.3 Synthetic Observations 83.3.1 BLISS Simulator 83.3.2 Synthetic Observation Characterization 83.4 Results 83.4.1 Performances of the Assimilation 83.4.2 Improvement in the Model Space 83.5 Conclusions References 84 Aerosol Optical Properties over Western Himalayas Region by Raman Lidar During the December 2019 Annular Solar Eclipse 84.1 Introduction 84.2 Methodology 84.2.1 Study Site 84.2.2 Raman Lidar System 84.3 Results 84.4 Conclusion References 85 The Clio HSRL Instrument Concept for the NASA AOS Mission 85.1 Measurement Objectives 85.2 Clio Design Overview 85.3 Expected Clio Performance 85.4 Path Forward References 86 Overview and Status of the Methane Remote Sensing Lidar Mission: MERLIN 86.1 Introduction 86.2 Methodology 86.3 Status of the Mission 86.3.1 Schedule 86.3.2 Expected Performance 86.4 Validation Efforts 86.5 Summary and Outlook References 87 A Simulation Capability Developed for NASA GSFC's Spaceborne Backscatter Lidars: Overview and Projected Performance for the Upcoming AOS Mission 87.1 Introduction 87.2 ALICAT Overview 87.3 Simulator Description 87.4 Instrument Performance 87.4.1 Minimal Detectable Backscatter 87.4.2 Signal-to-Noise Ratio 87.5 Summary References 88 Aerosol Typing and Spaceborne Lidars: Potentials and Limitations 88.1 Introduction 88.2 Aerosol Typing Schemes 88.2.1 The CALIPSO Aerosol Typing Scheme 88.2.2 The EarthCARE Aerosol Typing Scheme 88.2.3 Aerosol Typing from Ground-Based Lidar Systems 88.3 Potential and Limitations 88.4 Conclusions References 89 Correcting CALIOP Polarization Gain Ratios for Diurnal Variations 89.1 Introduction and Problem Statement 89.2 Near-Term Remediation 89.2.1 Nighttime PGR Bias Correction 89.2.2 Daytime PGR Estimates 89.2.3 Accommodating Day-to-Night and Night-to-Day Transitions 89.3 Consequences for CALIPSO Lidar Level 1 Data Products References 90 Performance Simulation of a Spaceborne Raman Lidar for ATLAS 90.1 Introduction 90.2 The End-to-End Simulator 90.3 Simulation Results References 91 Column Optical Depth (COD) Derived from CALIOP Ocean Surface Returns 91.1 Introduction 91.2 Ocean Derived Column Optical Depth Technique 91.3 Application to CALIPSO Algorithm 91.4 Comparisons to Similar Datasets 91.5 Conclusion References 92 Assessing Aeolus Aerosol Observational Capabilities for Data Assimilation in Air Quality and NWP Models 92.1 Introduction 92.2 Methodology 92.3 Outcomes 92.4 Future Steps References 93 High-Spectral-Resolution Lidars at the University of Wisconsin 93.1 Introduction 93.2 High-Spectral-Resolution Lidar Systems 93.3 MF2 High-Spectral Resolution Lidar Design 93.4 HSRL Data Example References 94 ATLID Algorithms Applied to ALADIN 94.1 Introduction 94.2 Accurate Attenuated Backscatter profiles 94.3 AEL-FM 94.4 AEL-PRO 94.5 Validation 94.5.1 Comparison with CALIPSO Observations 94.5.2 Comparisons with OMI AOT 94.6 Summary References Part IX Synergistic Use of Multiple Instruments and Techniques, Networks and Campaigns 95 Integrated Mobile System of Two-Wavelength Polarization Micro-pulse Lidar and Photometer for Aerosol Properties Retrievals: Comparisons with Reference Lidar 95.1 Introduction 95.2 Mobile Observations During FIREX-AQ Campaign in 2019 95.3 Continuous Measurements at ATOLL Platform, Lille 95.3.1 Study Case of Saharan Dust Transport 95.4 Conclusions and Perspectives References 96 Regional Changes in the Dominant Aerosol Type Over Europe During the ACTRIS COVID-19 Campaign 96.1 Instrumentation and Methodology 96.2 Results 96.2.1 Geographical Clustering 96.2.2 Urban and Rural Clustering 96.3 Conclusions References 97 The Role of Dry Layers and Cold Pools in the Activation of Mesoscale Convective Systems: A Characterization Study Based on the Combined Use of Raman Lidar and DIAL Measurements and MESO-NH Model Simulations 97.1 Introduction 97.2 Results 97.3 Conclusions References 98 Advances in Characterizing Pollution Transport with Ground-Based and Airborne Profilers: Case Studies Within Houston, TX 98.1 Introduction to TRACER-AQ 98.2 Profiling Platforms Used During TRACER-AQ 98.2.1 HSRL-2/DIAL 98.2.2 TOLNet and MPLNET 98.2.3 Pandora Spectrometer 98.2.4 Ozonesondes 98.3 Discussion 98.4 Conclusion References 99 First Results of Inverted Aerosol Properties Through GRASP Algorithm, Using Polarized Data from the Multiwavelength Sun-Sky-Lunar Photometer in Barcelona, Spain 99.1 Introduction 99.2 Material and Methods 99.2.1 Ground-Based Remote Sensing 99.2.2 Data Preparation 99.2.3 Data Synergy 99.3 Results and Discussion 99.3.1 D0, PD0, D1 and PD1 Configurations 99.3.2 D2 and D3 Configurations 99.4 Conclusions and Outlook References 100 Radiative Budget in the Lower Tropical Stratosphere from the Combination of Balloon-Borne Lidar and Radiometric Measurements 100.1 Scientific Context and Balloon-Borne Payload 100.2 Balloon-Borne Lidar Observations 100.3 Discussion 100.4 Perspectives References 101 Spatial Distribution Analysis of the TROPOMI Aerosol Layer Height: A Pixel-by-Pixel Comparison to EARLINET and CALIOP Observations 101.1 Introduction 101.1.1 Scope of the Study 101.2 Instrumentation and Data 101.2.1 TROPOMI S5P Data 101.2.2 Ground-Based Lidar Data (EARLINET) 101.2.3 CALIOP/CALIPSO Data 101.3 Validation Methodology and Results 101.3.1 Comparison of TROPOMI ALH Against EARLINET 101.3.2 Comparison of TROPOMI ALH Against CALIPSO 101.4 Conclusions References 102 First Results from the Aeolus Reference Lidar eVe During the Tropical Campaign JATAC at Cabo Verde 102.1 Introduction 102.2 The eVe Lidar 102.3 The JATAC Campaign 102.3.1 Lidar Intercomparison (eVe vs. PollyXT) 102.3.2 Aeolus Evaluation Using eVe Measurements 102.4 Summary References 103 Analysis of a Mid-Atlantic Ozone Episode Using TOLNet and Pandora 103.1 Introduction 103.2 Data and Methods 103.3 Results and Summary References 104 A Difference of the Depolarization Ratio Detected at Locally Generated Dust and Transported Asian Dust Over Japan with AD-Net 104.1 Introduction 104.2 Lidar Observations in AD-Net 104.3 Periods of Locally Generated Dust and Asian Dust 104.4 Statistical Analysis of Optical Parameters 104.5 Climatology of Local Dust and Asian Dust 104.6 Concluding Remarks References 105 Identification of Mixed-Phase Clouds Using Combined CALIPSO Lidar and Imaging Infrared Radiometer Observations 105.1 Introduction 105.2 Results 105.2.1 IIR Retrievals in the Hu Phase Diagrams 105.2.2 Water Clouds 105.2.3 HOI Clouds 105.3 Concluding Remarks References 106 Huntsville Mobile RO3QET Launch 106.1 Introduction 106.2 Instruments 106.3