scholarly journals Preliminary Studies on Atmospheric Monitoring by Employing a Portable Unmanned Mie-Scattering Scheimpflug Lidar System

2019 ◽  
Vol 11 (7) ◽  
pp. 837 ◽  
Author(s):  
Zhi Liu ◽  
Limei Li ◽  
Hui Li ◽  
Liang Mei
Keyword(s):  
Urban Areas ◽  
Continuous Wave ◽  
Promising Result ◽  
Image Sensor ◽  
Mie Scattering ◽  
Urban Atmosphere ◽  
Pollution Monitoring ◽  
Atmospheric Measurements ◽  
Lidar System ◽  
Atmospheric Remote Sensing

A portable unmanned Mie-scattering Scheimpflug lidar system has been designed and implemented for atmospheric remote sensing. The Scheimpflug lidar system employs a continuous-wave high-power 808 nm laser diode as the light source and the emitted laser beam is collimated by an F6 lens with a 100 mm aperture. Atmospheric backscattering light is collected by a F5 lens with a 150 mm aperture and then detected by a 45° tilted image sensor. The separation between the transmitting and the receiving optics is about 756 mm to satisfy the Scheimpflug principle. Unmanned outdoor atmospheric measurements were performed in an urban area to investigate system performance. Localized emissions can be identified by performing horizontal scanning measurements over the urban atmosphere for 107° approximately every 17 min. The temporal variation of the vertical aerosol structure in the boundary layer has also been studied through zenith scanning measurements. The promising result shows great potential of the present portable lidar system for unmanned atmospheric pollution monitoring in urban areas.

scholarly journals Recent Advances in Aerosol and Trace Gas Monitoring by Employing the Scheimpflug Lidar Techniques

2020 ◽  
Vol 237 ◽  
pp. 07022
Author(s):  
Liang Mei ◽  
Zheng Kong ◽  
Teng Ma ◽  
Zhi Liu ◽  
Zhenfeng Gong ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Laser Diodes ◽  
Image Sensor ◽  
Trace Gas ◽  
Light Sources ◽  
Continuous Wave Laser ◽  
Gas Monitoring ◽  
Power Laser ◽  
Recent Advances ◽  
Atmospheric Remote Sensing

Lidar techniques, based on the time-of-flight principle, have been widely employed in atmospheric remote sensing since decades. The Scheimpflug lidar (SLidar) technique, which employing robust high-power laser diodes as light sources and highly integrated CCD/CMOS image sensor as detectors, has been recently developed for various atmospheric applications. Range-resolved atmospheric backscattering signal is obtained by capturing the backscattering imaging of transmitted continuous-wave laser beam based on the Scheimpflug principle. This paper reported recent advances in aerosol and trace gas monitoring by employing the SLidar techniques.

Lidar system for air-pollution monitoring over urban areas

1997 ◽  
Author(s):  
Irina V. Moskalenko ◽  
Djolinard A. Shecheglov ◽  
Nikolai A. Molodtsov
Keyword(s):  
Air Pollution ◽  
Urban Areas ◽  
Pollution Monitoring ◽  
Lidar System ◽  
Air Pollution Monitoring

scholarly journals Experimental Calibration of the Overlap Factor for the Pulsed Atmospheric Lidar by Employing a Collocated Scheimpflug Lidar

2020 ◽  
Vol 12 (7) ◽  
pp. 1227
Author(s):  
Liang Mei ◽  
Teng Ma ◽  
Zhen Zhang ◽  
Ruonan Fei ◽  
Kun Liu ◽  
...  
Keyword(s):  
Calibration Method ◽  
Mie Scattering ◽  
Measurement Range ◽  
Atmospheric Conditions ◽  
Lidar System ◽  
Experimental Calibration ◽  
Near Surface ◽  
System A ◽  
Atmospheric Remote Sensing ◽  
Overlap Factor

Lidar techniques have been widely employed for atmospheric remote sensing during past decades. However, an important drawback of the traditional atmospheric pulsed lidar technique is the large blind range, typically hundreds of meters, due to incomplete overlap between the transmitter and the receiver, etc. The large blind range prevents the successful retrieval of the near-ground aerosol profile, which is of great significance for both meteorological studies and environmental monitoring. In this work, we have demonstrated a new experimental approach to calibrate the overlap factor of the Mie-scattering pulsed lidar system by employing a collocated Scheimpflug lidar (SLidar) system. A calibration method of the overlap factor has been proposed and evaluated with lidar data measured in different ranges. The overlap factor, experimentally determined by the collocated SLidar system, has also been validated through horizontal comparison measurements. It has been found out that the median overlap factor evaluated by the proposed method agreed very well with the overlap factor obtained by the linear fitting approach with the assumption of homogeneous atmospheric conditions, and the discrepancy was generally less than 10%. Meanwhile, simultaneous measurements employing the SLidar system and the pulsed lidar system have been carried out to extend the measurement range of lidar techniques by gluing the lidar curves measured by the two systems. The profile of the aerosol extinction coefficient from the near surface at around 90 m up to 28 km can be well resolved in a slant measurement geometry during nighttime. This work has demonstrated a great potential of employing the SLidar technique for the calibration of the overlap factor and the extension of the measurement range for pulsed lidar techniques.

Atmospheric measurements over oceans on German research vessels

2020 ◽  
Author(s):  
Stefan Kinne
Keyword(s):  
Remote Sensing ◽  
Satellite Remote Sensing ◽  
System Modeling ◽  
Data Sets ◽  
Atmospheric Measurements ◽  
Earth System Modeling ◽  
Atmospheric Remote Sensing ◽  
German Research ◽  
Ground Monitoring ◽  
Global Data

<p>Ground-based remote sensing of atmospheric properties complements satellite remote sensing from space. Hereby the well-defined solar background of ground-based samples offers data of higher accuracy, which help to constrain (needed) assumptions in global data-sets of satellite remote sensing and earth system modeling. With ground monitoring largely limited to land or island surfaces, efforts have been made to add at least a few reference data over oceans with atmospheric remote sensing activities during ship cruises of opportunity. This presentation reports on recent voyages with German Research vessels (i.e. SONNE, MERIAN, METEOR and POLARSTERN) and how samples on these voyages have contributed to a better representation of marine properties for aerosol, trace-gases and clouds. Aside from establishing references for satellite remote sensing and modeling, relationships among different atmospheric properties also offer observational constrains for parametrizations of atmospheric processes in modeling.  </p>

scholarly journals Atmospheric Pollution Monitoring in Urban Area by Employing a 450-nm Lidar System

Sensors ◽  
2018 ◽  
Vol 18 (6) ◽  
pp. 1880 ◽  
Author(s):  
Zheng Kong ◽  
Zhi Liu ◽  
Lishan Zhang ◽  
Peng Guan ◽  
Limei Li ◽  
...  
Keyword(s):  
Urban Area ◽  
Atmospheric Pollution ◽  
Pollution Monitoring ◽  
Lidar System

Basics and first experiments demonstrating isolation improvements in the agile polarimetric FM-CW radar – PARSAX

2010 ◽  
Vol 2 (3-4) ◽  
pp. 419-428 ◽  
Author(s):  
Oleg A. Krasnov ◽  
Galina P. Babur ◽  
Zongbo Wang ◽  
Leo P. Ligthart ◽  
Fred van der Zwan
Keyword(s):  
Continuous Wave ◽  
Operational Performance ◽  
Digital Receiver ◽  
Operational Mode ◽  
Target Polarization ◽  
Atmospheric Remote Sensing ◽  
Radar Applications ◽  
Radar Measurements ◽  
Polarization Scattering Matrix ◽  
Cw Radar

The article describes the IRCTR PARSAX radar system, the S-band high-resolution Doppler polarimetric frequency modulated continuous wave (FM-CW) radar with dual-orthogonal sounding signals, which has the possibility to measure all elements of the radar target polarization scattering matrix simultaneously, in one sweep. The performance of such radar depends of the level of sounding signals orthogonality. In the main operational mode, the radar will be used for atmospheric remote sensing and polarimetric studies of ground-based targets. In such mode it will use a pair of synchronous linearly- frequency modulated (LFM) continuous signals with opposite frequency excursions of 50 MHz and duration of 1 ms. Such a combination of sounding signals has limited orthogonality even for huge BT-products, which produce cross-channel interferences. These interferences in case of radar scene with multiple pointed and distributed targets can completely degrade radar operational performance. In this article, we propose simple and effective technique to suppress interferences and to restore radar performance. The technique has been tested using simulation and has been implemented in multi-channel digital receiver of the PARSAX radar. The real radar measurements presented to illustrate effectiveness of cross-channel interferences suppression. The proposed technique can be useful not only for polarimetric radar design, but also in much wide radar applications, which use waveforms with high orthogonality.

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