Current Research in Lidar Technology Used for the Remote Sensing of Atmospheric Aerosols

Abstract

Lidars are active optical remote sensing instruments with unique capabilities for atmospheric sounding. A manifold of atmospheric variables can be profiled using different types of lidar: concentration of species, wind speed, temperature, etc. Among them, measurement of the properties of aerosol particles, whose influence in many atmospheric processes is important but is still poorly stated, stands as one of the main fields of application of current lidar systems. This paper presents a review on fundamentals, technology, methodologies and state-of-the art of the lidar systems used to obtain aerosol information. Retrieval of structural (aerosol layers profiling), optical (backscatter and extinction coefficients) and microphysical (size, shape and type) properties requires however different levels of instrumental complexity; this general outlook is structured following a classification that attends these criteria. Thus, elastic systems (detection only of emitted frequencies), Raman systems (detection also of Raman frequency-shifted spectral lines), high spectral resolution lidars, systems with depolarization measurement capabilities and multi-wavelength instruments are described, and the fundamentals in which the retrieval of aerosol parameters is based is in each case detailed.

Accuracy–Power Controllable LiDAR Sensor System with 3D Object Recognition for Autonomous Vehicle

“…As RADAR sensors develop in sophistication, the research on low-power consumption of RADAR sensors continues [ 29 , 30 ]. However, because the research period of multi-channel LiDAR sensors has not been relatively long, judging by the technology trend, the research and development of an improved sensing distance, a point-cloud signal-processing method, and accuracy and recognition are being conducted [ 31 , 32 , 33 , 34 ]. Because the research of a multi-channel LiDAR sensor is focused on improving performance, the research on low-power consumption for vehicles has been insufficient.…”

An Overview of Lidar Imaging Systems for Autonomous Vehicles

“…Remote sensing has been one of the paramount applications of the technology, either from ground-based stations (e.g., for aerosol monitoring) or as aerial or space-borne instrumentation, typically for Earth observation applications in different wavebands. A number of review papers [3], introductory texts [4] or comprehensive books [5,6] have been made available on the topic across the years. Lidar had become already so relevant that a full industry related to remote sensing and mapping was developed.…”

A novel lidar gradient cluster analysis method of nocturnal boundary layer detection during air pollution episodes

“…The stable condition shows greater agreement between lidar and radiosonde than the unstable condition because of the complex aerosol structure that complicates NBLH retrieval (Emeis and Schäfer, 2006;Martucci et al, 2007;Sawyer and Li, 2013). At night, the NBLH, as determined by elastic lidar, is either the top of the residual layer or the top of the mechanically driven sur-face mixing layer (Dang et al, 2019a;Yuval et al, 2020). In the absence of external forces, aerosols in the atmosphere become stratified, resulting in single or multiple layers (elevated or advent aerosols), depending on the location and type of the atmospheric aerosols (Dudeja, 2019;Martucci et al, 2007).…”

“…In the absence of external forces, aerosols in the atmosphere become stratified, resulting in single or multiple layers (elevated or advent aerosols), depending on the location and type of the atmospheric aerosols (Dudeja, 2019;Martucci et al, 2007). A more complex vertical backscatter signal profile can also be formed under specific environmental conditions, such as cloud contamination and local signal noise effect (Dang et al, 2019a;Stull, 1988).…”