Recent modifications and measurements with a ground-based lidar system

1993 ◽  
Author(s):  
David C. Woods ◽  
David M. Winker ◽  
Otto Youngbluth, Jr. ◽  
Mary T. Osborn ◽  
Robert J. DeCoursey
Keyword(s):  
Lidar System ◽  
Ground Based Lidar

Designing and building a novel, ground-based lidar system for aerosol typing in the Planetary Boundary Layer

2020 ◽  
Author(s):  
Rebecca Howe ◽  
Ioannis Binnietoglou ◽  
Jamie O.D. Williams ◽  
Alexandras Fragkos ◽  
George Tsaknakis ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Planetary Boundary Layer ◽  
Lidar System ◽  
Ground Based Lidar

scholarly journals Application of Lidar Data to Assist Airmass Discrimination at the Whistler Mountaintop Observatory

2012 ◽  
Vol 51 (10) ◽  
pp. 1733-1739 ◽  
Author(s):  
John P. Gallagher ◽  
Ian G. McKendry ◽  
Paul W. Cottle ◽  
Anne Marie Macdonald ◽  
W. Richard Leaitch ◽  
...  
Keyword(s):  
Vapor Condensation ◽  
Lidar Data ◽  
Free Troposphere ◽  
Atmospheric Layer ◽  
Lidar System ◽  
Air Samples ◽  
Water Vapor Condensation ◽  
Air Chemistry ◽  
Ground Based Lidar ◽  
Time Series Images

AbstractA ground-based lidar system that has been deployed in Whistler, British Columbia, Canada, since the spring of 2010 provides a means of evaluating vertical aerosol structure in a mountainous environment. This information is used to help to determine when an air chemistry observatory atop Whistler Mountain (2182 m MSL) is within the free troposphere or is influenced by the valley-based planetary boundary layer (PBL). Three case studies are presented in which 1-day time series images of backscatter data from the lidar are analyzed along with concurrent meteorological and air-chemistry datasets from the mountaintop site. The cases were selected to illustrate different scenarios of diurnal PBL evolution that are expected to be common during their respective seasons. The lidar images corroborate assumptions about PBL influence as derived from analysis of diurnal trends in water vapor, condensation nuclei, and ozone. Use of all of these datasets together bolsters efforts to determine which atmospheric layer the site best represents, which is important when evaluating the provenance of air samples.

Ozone and Water Vapor Monitoring Using a Ground-Based Lidar System

1983 ◽  
pp. 223-228
Author(s):  
G. Mégie ◽  
J. Pelon ◽  
J. Lefrère ◽  
C. Cahen ◽  
P. H. Flamant
Keyword(s):  
Water Vapor ◽  
Lidar System ◽  
Ground Based Lidar

scholarly journals Vertical distribution of aerosols in the vicinity of Mexico City during MILAGRO-2006 Campaign

2010 ◽  
Vol 10 (3) ◽  
pp. 1017-1030 ◽  
Author(s):  
P. A. Lewandowski ◽  
W. E. Eichinger ◽  
H. Holder ◽  
J. Prueger ◽  
J. Wang ◽  
...  
Keyword(s):  
Size Distribution ◽  
Mexico City ◽  
Mass Concentration ◽  
Heavy Traffic ◽  
Aerosol Size Distribution ◽  
Lidar System ◽  
Aerosol Mass ◽  
Aerosol Mass Concentration ◽  
Lidar Measurements ◽  
Ground Based Lidar

Abstract. On 7 March 2006, a mobile, ground-based, vertical pointing, elastic lidar system made a North-South transect through the Mexico City basin. Column averaged, aerosol size distribution (ASD) measurements were made on the ground concurrently with the lidar measurements. The ASD ground measurements allowed calculation of the column averaged mass extinction efficiency (MEE) for the lidar system (1064 nm). The value of column averaged MEE was combined with spatially resolved lidar extinction coefficients to produce total aerosol mass concentration estimates with the resolution of the lidar (1.5 m vertical spatial and 1 s temporal). Airborne ASD measurements from DOE G-1 aircraft made later in the day on 7 March 2006, allowed the evaluation of the assumptions of constant ASD with height and time used for estimating the column averaged MEE. The results showed that the aerosol loading within the basin is about twice what is observed outside of the basin. The total aerosol base concentrations observed in the basin are of the order of 200 μg/m3 and the base levels outside are of the order of 100 μg/m3. The local heavy traffic events can introduce aerosol levels near the ground as high as 900 μg/m3. The article presents the methodology for estimating aerosol mass concentration from mobile, ground-based lidar measurements in combination with aerosol size distribution measurements. An uncertainty analysis of the methodology is also presented.

scholarly journals Climatology Of Thin Cirrus Clouds at Gadanki (13.5°N, 79.2°E) Using Ground Based Lidar And Satellite Based Measurements

2014 ◽  
Vol XL-8 ◽  
pp. 283-286
Author(s):  
G. S. Motty ◽  
G. S. Jayeshlal ◽  
M. Satyanarayana
Keyword(s):  
Optical Properties ◽  
High Altitude ◽  
Optical Depth ◽  
Global Scale ◽  
Cirrus Clouds ◽  
Statistical Characteristics ◽  
Lidar System ◽  
Radiative Balance ◽  
Geometrical Properties ◽  
Ground Based Lidar

High altitude cirrus clouds play a significant role in the radiative balance of Earth atmosphere system. Information on cirrus occurrences and their optical properties is essential for climate modeling studies. The influence of high altitude thin cirrus clouds on the climate is important due to their optical and thermodynamic properties. In order to quantify their effect on atmosphere, the vertical structure and optical properties of these thin cirrus clouds are to be characterized. The Lidar technique has become a unique tool for detecting and characterizing cirrus clouds for their optical properties. Ground based LIDAR system offers an excellent way to obtain characteristic values on the cirrus formations, although the microphysical and optical properties of thin cirrus clouds can also obtained on global scale by the observations from Earth-orbiting Satellites .The ground-based lidar observations could provide more intensive measurements on continuous basis, compared to satellite observations. Utilising observations from both, the statistical characteristics, physical and optical properties of thin cirrus clouds can be retrieved more precisely. The present study is based on the ground based lidar measurements using the pulsed monostatic LIDAR system at the National Atmospheric Research Laboratory [NARL], Gadanki (13.5&deg; N, 79.2&deg; E), Andhra Pradesh, India. The data obtained in the altitude range of 8&minus;20 km are used for this study. Cirrus observations made using CALIPSO and MODIS satellites are compared with the ground based lidar data for systematic statistical study of cirrus climatology. Optically thin cirrus clouds (τ < 0.3) observed during 2009 are selected and their microphysical and geometrical properties are studied. The microphysical properties such as optical depth, lidar ratio and depolarisation ratio for cirrus clouds were obtained. It is observed that the variability in optical depth depends on the composition and thickness of the clouds. The relationships between various quantities were also processed. The study shows that the thin cirrus generally was present in higher altitudes and the optical properties show correlation with the height and the temperature.

scholarly journals The ESA-EVE Polarization Lidar for Assessing the Aeolus Aerosol Product Perfomance

2020 ◽  
Vol 237 ◽  
pp. 07025
Author(s):  
Peristera Paschou ◽  
Emmanouil Proestakis ◽  
Alexandra Tsekeri ◽  
Nikos Siomos ◽  
Antonis Gkikas ◽  
...  
Keyword(s):  
Spherical Particles ◽  
Polar Component ◽  
Doppler Lidar ◽  
Backscatter Coefficient ◽  
Lidar System ◽  
Ground Based Lidar ◽  
Reference Measurements ◽  
Aerosol Backscatter ◽  
Quality Assessment And Improvement ◽  
Polarized Radiation

We present the EVE lidar concept, a combined linear/circular polarization system, tailored to evaluate the spaceborne ALADIN Doppler lidar system aerosol retrievals. EVE, currently under development, aims to provide the ESA-Aeolus mission with a flexible, mobile reference ground-based lidar system capable of providing well-characterized fiducial reference measurements of aerosol optical properties. Since ALADIN detects only the co-polar component of the backscattered circularly polarized radiation, a portion of the received radiation gets lost, leading to an un-derestimation of the backscatter coefficient and the circular depolarization ratio in strongly depolarizing scenes with non-spherical particles. The main focus of the new EVE lidar is to quantify these uncertainties and to evaluate aerosol backscatter/extinction retrievals for Aeolus, and later also for EarthCARE product validation, quality assessment and improvement.

scholarly journals Assessment of the CALIPSO Lidar 532 nm version 3 lidar ratio models using a ground-based lidar and AERONET sun photometers in Brazil

2013 ◽  
Vol 6 (1) ◽  
pp. 1143-1199 ◽  
Author(s):  
F. J. S. Lopes ◽  
E. Landulfo ◽  
M. A. Vaughan
Keyword(s):  
South American ◽  
Lidar System ◽  
Air Mass ◽  
Air Masses ◽  
Uncertainty Range ◽  
Percentage Difference ◽  
Lidar Ratio ◽  
Ground Based Lidar ◽  
Good Agreement

Abstract. Since the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite first began probing the Earth's atmosphere on 13 June 2006, several research groups dedicated to investigating the atmosphere's optical properties have conducted measurement campaigns to validate the CALIPSO data products. Recently, in order to address the lack of CALIPSO validation studies in the Southern Hemisphere, and especially the South American continent, the Lasers Environmental Applications Research Group at Brazil's Nuclear and Energy Research Institute (IPEN) initiated efforts to assess CALIPSO's aerosol lidar ratio estimates using two ground-based remote sensing instruments: a single elastic backscatter lidar system and the AERONET sun photometers installed at five different locations in Brazil. In this study we develop a validation methodology to assess the accuracy of the modeled values of the lidar ratios used by the CALIPSO extinction algorithms. We recognize that the quality of any comparisons between satellite and ground-based measurements depends on the degree to which the instruments are collocated, and that even selecting the best spatial and temporal matches does not provide an unequivocal guarantee that both instruments are measuring the same air mass. The validation methodology presented in this study therefore applies backward and forward air mass trajectories in order to obtain the best possible match between the air masses sampled by the satellite and the ground-based instruments, and thus reduces the uncertainties associated with aerosol air mass variations. Quantitative comparisons of lidar ratio values determined from the combination of AERONET optical depth measurements and CALIOP integrated attenuated backscatter show good agreement with the model values assigned by the CALIOP algorithm. These comparisons yield a mean percentage difference of −2% ± 26%. Similarly, lidar ratio values retrieved by the elastic backscatter lidar system at IPEN show a mean percentage difference of −2% ± 15% when compared with CALIOP's lidar ratio. These results confirm the accuracy in the lidar ratio estimates provided by the CALIOP algorithms to within an uncertainty range of no more than 30%.

scholarly journals Utilizing ground-based LIDAR measurements to aid autonomous airdrop systems

2017 ◽  
Vol 231 (10) ◽  
pp. 1763-1778
Author(s):  
Martin Cacan ◽  
Edward Scheuermann ◽  
Michael Ward ◽  
Mark Costello ◽  
Nathan Slegers
Keyword(s):  
Wind Field ◽  
Ground Level ◽  
Light Detection And Ranging ◽  
Primary Sources ◽  
Time Data ◽  
Lidar System ◽  
Lidar Measurements ◽  
Real Time Data ◽  
Ground Based Lidar ◽  
Improving Accuracy

Uncertainty in atmospheric winds represents one of the primary sources of landing error in airdrop systems. In this work, a ground-based LIDAR system samples the wind field at discrete points above the target and transmits real-time data to approaching autonomous airdrop systems. In simulation and experimentation, the inclusion of a light detection and ranging (LIDAR) system showed a maximum of 40% improvement over unaided autonomous airdrop systems. Wind information nearest ground level has the largest impact on improving accuracy.

Registration and Fusion of UAV LiDAR System Sequence Images and Laser Point Clouds

2020 ◽  
Author(s):  
Jiayong Yu ◽  
Longchen Ma ◽  
Maoyi Tian, ◽  
Xiushan Lu
Keyword(s):  
Point Cloud ◽  
Image Data ◽  
Point Clouds ◽  
Optical Image ◽  
Point Cloud Data ◽  
Feature Points ◽  
Lidar System ◽  
Registration Accuracy ◽  
Cloud Data ◽  
Intensity Image

The unmanned aerial vehicle (UAV)-mounted mobile LiDAR system (ULS) is widely used for geomatics owing to its efficient data acquisition and convenient operation. However, due to limited carrying capacity of a UAV, sensors integrated in the ULS should be small and lightweight, which results in decrease in the density of the collected scanning points. This affects registration between image data and point cloud data. To address this issue, the authors propose a method for registering and fusing ULS sequence images and laser point clouds, wherein they convert the problem of registering point cloud data and image data into a problem of matching feature points between the two images. First, a point cloud is selected to produce an intensity image. Subsequently, the corresponding feature points of the intensity image and the optical image are matched, and exterior orientation parameters are solved using a collinear equation based on image position and orientation. Finally, the sequence images are fused with the laser point cloud, based on the Global Navigation Satellite System (GNSS) time index of the optical image, to generate a true color point cloud. The experimental results show the higher registration accuracy and fusion speed of the proposed method, thereby demonstrating its accuracy and effectiveness.

Sign in / Sign up

Export Citation Format

Share Document