WorldWideScience

Sample records for site micropulse lidar

  1. A one-year climatology using data from the Southern Great Plains (SGP) site micropulse lidar

    Energy Technology Data Exchange (ETDEWEB)

    Mace, G.G.; Ackerman, T.P. [Penn State Univ., University Park, PA (United States); Spinhirne, J.; Scott, S. [NASA Goddard Space Flight Center, Greenbelt, MD (United States)

    1996-04-01

    The micropulse lidar (MPL) has been operational at the Southern Great Plains (SGP) site of the Atmospheric Radiation Measurement Program for the past 15 months. The compact MPL is unique among research lidar systems in that it is eye-safe and operates continuously, except during precipitation. The MPL is capable of detecting cloud base throughout the entire depth of the troposphere. The MPL data set is an unprecedented time series of cloud heights. It is a vital resource for understanding the frequency of cloud ocurrence and the impact of clouds on the surface radiation budget, as well as for large-scale model validation and satellite retrieval verification. The raw lidar data are processed for cloud base height at a temporal frequency of one minute and a vertical resolution of 270 m. The resultant time series of cloud base is used to generate histograms as a function of month and time of day. Sample results are described.

  2. The Micro-Pulse Lidar Network (MPLNET): A Federated Network of Micro-pulse Lidars and AERONET Sunphotometers

    Science.gov (United States)

    Welton, Ellsworth J.; Campbell, James R.; Spinhirne, James D.; Berkoff, Timothy A.; Holben, Brent; Tsay, Si-Chee

    2004-01-01

    We present the formation of a new global-ground based eye-safe lidar network, the NASA Micro-Pulse Lidar Network (MPLNET). The aim of MPLNET is to acquire long- term observations of aerosol and cloud vertical profiles at unique geographic sites within the NASA Aerosol Robotic Network (AERONET). MPLNET utilizes standard instrumentation and data processing algorithms for efficient network operations and direct comparison of data between each site. The micro-pulse lidar is eye-safe, compact, and commercially available, and most easily allows growth of the network without sacrificing standardized instrumentation goals. Network growth follows a federated approach, pioneered by AERONET, wherein independent research groups may join MPLNET with their own instrument and site. MPLNET sites produce not only vertical profile data, but also column-averaged products already available from AERONET (aerosol optical depth, sky radiance, size distributions). Algorithms are presented for each MPLNET data product. Real-time Level 1 data products (next-day) include daily lidar signal images from the surface to -2Okm, and Level 1.5 aerosol extinction profiles at times co-incident with AERONET observations. Quality assured Level 2 aerosol extinction profiles are generated after screening the Level 1.5 results and removing bad data. Level 3 products include continuous day/night aerosol extinction profiles, and are produced using Level 2 calibration data. Rigorous uncertainty calculations are presented for all data products. Analysis of MPLNET data show the MPL and our analysis routines are capable of successfully retrieving aerosol profiles, with the strenuous accounting of uncertainty necessary for accurate interpretation of the results.

  3. The Micro-Pulse Lidar Network (MPL-Net)

    Science.gov (United States)

    Welton, Ellsworth J.; Campbell, James R.; Berkoff, Timothy A.; Spinhirne, James D.; Tsay, Si-Chee; Holben, Brent; Shiobara, Masataka; Starr, David OC. (Technical Monitor)

    2002-01-01

    In the early 1990s, the first small, eye-safe, and autonomous lidar system was developed, the Micro-pulse Lidar (MPL). The MPL has proven to be useful in the field because it can be automated, runs continuously (day and night), is eye-safe, can easily be transported and set up, and has a small field-of-view which limits multiple scattering concerns. The MPL acquires signal profiles of backscattered laser light from aerosols and clouds. The signals are analyzed to yield multiple layer heights, optical depths of each layer, average extinction-to-backscatter ratio of each layer, and profiles of extinction in each layer. The MPL has been used in a wide variety of field studies over the past 10 years, leading to nearly 20 papers and many conference presentations. In 2000, a new project using MPL systems was started at NASA Goddard Space Flight Center. The MPL-Net project is currently working to establish a worldwide network of MPL systems, all co-located with NASA's AERONET sunphotometers for joint measurements of optical depth and sky radiance. Automated processing algorithms have been developed to produce data products on a next day basis for all sites and some field experiments. Initial results from the first several sites are shown, along with aerosol data collected during several major field campaigns. Measurements of the aerosol extinction-to-backscatter ratio at several different geographic regions, and for various aerosol types are shown. This information is used to improve the construction of look up tables of the ratio, needed to process aerosol profiles acquired with satellite based lidars.

  4. Initial Results from the Micro-pulse Lidar Network (MPL-Net)

    Science.gov (United States)

    Welton, Ellsworth J.; Campbell, James R.; Berkoff, Timothy A.; Spinhirne, James D.; Ginoux, Paul; Starr, David OC. (Technical Monitor)

    2001-01-01

    The micro-pulse lidar system (MPL) was developed in the early 1990s and was the first small, eye-safe, and autonomous lidar built for full time monitoring of cloud and aerosol vertical distributions. In 2000, a new project using MPL systems was started at NASA Goddard Space Flight Center. This new project, the Micro-pulse Lidar Network or MPL-Net, was created to provide long-term observations of aerosol and cloud vertical profiles at key sites around the world. This is accomplished using both NASA operated sites and partnerships with other organizations owning MPL systems. The MPL-Net sites are co-located with NASA AERONET sunphotometers to provide aerosol optical depth data needed for calibration of the MPL. In addition to the long-term sites, MPL-Net provides lidar support for a limited number of field experiments and ocean cruises each year. We will present an overview of the MPL-Net project and show initial results from the first two MPL-Net sites at the South Pole and at Goddard Space Flight Center. Observations of dust layers transported from the Gobi desert, across the Pacific Ocean, to the east coast of the United States will also be shown. MPL-Net affiliated instruments were in place at the desert source region in China, on a research vessel in the Sea of Japan, at ARM sites in Alaska and Oklahoma, and finally at our home site in Maryland (GSFC) during the massive dust storms that occurred in April 2001. The MPL observations of dust layers at each location are shown in comparison to dust layers predicted using the Georgia Tech/Goddard Global Ozone Chemistry Aerosol Radiation and Transport model (GOCART). Finally, the MPL-Net project is the primary ground-validation program for the Geo-Science Laser Altimeter System (GLAS) satellite lidar project (launch date 2002). We will present an overview demonstrating how MPL-Net results are used to help prepare the GLAS data processing algorithms and assist in the calibration/validation of the GLAS data products.

  5. Initial Results From The Micro-pulse Lidar Network (MPL-Net)

    Science.gov (United States)

    Welton, E. J.; Campbell, J. R.; Berkoff, T. A.; Spinhirne, J. D.; Ginoux, P.

    2001-12-01

    The micro-pulse lidar system (MPL) was developed in the early 1990s and was the first small, eye-safe, and autonomous lidar built for fulltime monitoring of cloud and aerosol vertical distributions. In 2000, a new project using MPL systems was started at NASA Goddard Space Flight Center. This new project, the Micro-pulse Lidar Network or MPL-Net, was created to provide long-term observations of aerosol and cloud vertical profiles at key sites around the world. This is accomplished using both NASA operated sites and partnerships with other organizations owning MPL systems. The MPL-Net sites are co-located with NASA AERONET sunphotometers to provide aerosol optical depth data needed for calibration of the MPL. In addition to the long-term sites, MPL-Net provides lidar support for a limited number of field experiments and ocean cruises each year. We will present an overview of the MPL-Net project and show initial results from the first two MPL-Net sites at the South Pole and at Goddard Space Flight Center. Observations of dust layers transported from the desert regions of China, across the Pacific Ocean, to the east coast of the United States will also be shown. MPL-Net affiliated instruments were in place at the desert source region in China, on a research vessel in the Sea of Japan, at ARM sites in Alaska and Oklahoma, and finally at our home site in Maryland (GSFC) during the massive dust storms that occurred in April 2001. The MPL observations of dust layers at each location are shown in comparison to dust layers predicted using the Georgia Tech/Goddard Global Ozone Chemistry Aerosol Radiation and Transport model (GOCART). Finally, the MPL-Net project is the primary ground-validation program for the Geo-Science Laser Altimeter System (GLAS) satellite lidar project (launch date 2002). We will present an overview demonstrating how MPL-Net results are used to help prepare the GLAS data processing algorithms and assist in the calibration/validation of the GLAS data

  6. Determining Cloud Thermodynamic Phase from Micropulse Lidar Network Data

    Science.gov (United States)

    Lewis, Jasper R.; Campbell, James; Lolli, Simone; Tan, Ivy; Welton, Ellsworth J.

    2017-01-01

    Determining cloud thermodynamic phase is a critical factor in studies of Earth's radiation budget. Here we use observations from the NASA Micro Pulse Lidar Network (MPLNET) and thermodynamic profiles from the Goddard Earth Observing System, version 5 (GEOS-5) to distinguish liquid water, mixed-phase, and ice water clouds. The MPLNET provides sparse global, autonomous, and continuous measurements of clouds and aerosols which have been used in a number of scientific investigations to date. The use of a standardized instrument and a common suite of data processing algorithms with thorough uncertainty characterization allows for straightforward comparisons between sites. Lidars with polarization capabilities have recently been incorporated into the MPLNET project which allows, for the first time, the ability to infer a cloud thermodynamic phase. This presentation will look specifically at the occurrence of ice and mixed phase clouds in the temperature region of -10 C to -40 C for different climatological regions and seasons. We compare MPLNET occurrences of mixed-phase clouds to an historical climatology based on observations from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) instrument aboard the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) spacecraft.

  7. A Micropulse eye-safe all-fiber molecular backscatter coherent temperature lidar

    Directory of Open Access Journals (Sweden)

    Abari Cyrus F.

    2016-01-01

    Full Text Available In this paper, we analyze the performance of an all-fiber, micropulse, 1.5 μm coherent lidar for remote sensing of atmospheric temperature. The proposed system benefits from the recent advances in optics/electronics technology, especially an all-fiber image-reject homodyne receiver, where a high resolution spectrum in the baseband can be acquired. Due to the presence of a structured spectra resulting from the spontaneous Rayleigh-Brillouine scattering, associated with the relevant operating regimes, an accurate estimation of the temperature can be carried out. One of the main advantages of this system is the removal of the contaminating Mie backscatter signal by electronic filters at the baseband (before signal conditioning and amplification. The paper presents the basic concepts as well as a Monte-Carlo system simulation as the proof of concept.

  8. An Aerosol Extinction-to-Backscatter Ratio Database Derived from the NASA Micro-Pulse Lidar Network: Applications for Space-based Lidar Observations

    Science.gov (United States)

    Welton, Ellsworth J.; Campbell, James R.; Spinhime, James D.; Berkoff, Timothy A.; Holben, Brent; Tsay, Si-Chee; Bucholtz, Anthony

    2004-01-01

    Backscatter lidar signals are a function of both backscatter and extinction. Hence, these lidar observations alone cannot separate the two quantities. The aerosol extinction-to-backscatter ratio, S, is the key parameter required to accurately retrieve extinction and optical depth from backscatter lidar observations of aerosol layers. S is commonly defined as 4*pi divided by the product of the single scatter albedo and the phase function at 180-degree scattering angle. Values of S for different aerosol types are not well known, and are even more difficult to determine when aerosols become mixed. Here we present a new lidar-sunphotometer S database derived from Observations of the NASA Micro-Pulse Lidar Network (MPLNET). MPLNET is a growing worldwide network of eye-safe backscatter lidars co-located with sunphotometers in the NASA Aerosol Robotic Network (AERONET). Values of S for different aerosol species and geographic regions will be presented. A framework for constructing an S look-up table will be shown. Look-up tables of S are needed to calculate aerosol extinction and optical depth from space-based lidar observations in the absence of co-located AOD data. Applications for using the new S look-up table to reprocess aerosol products from NASA's Geoscience Laser Altimeter System (GLAS) will be discussed.

  9. Macrophysical and optical properties of mid-latitude cirrus clouds over a semi-arid area observed by micro-pulse lidar

    International Nuclear Information System (INIS)

    Wang, Jin; Zhang, Lei; Huang, Jianping; Cao, Xianjie; Liu, Ruijin; Zhou, Bi; Wang, Hongbin; Huang, Zhongwei; Bi, Jianrong; Zhou, Tian; Zhang, Beidou; Wang, Tengjiao

    2013-01-01

    Macrophysical and optical characteristics of cirrus clouds were investigated at the Semi-Arid Climate Observatory and Laboratory (SACOL; 35.95°N, 104.14°E) of Lanzhou University in northwest China during April to December 2007 using micro-pulse lidar data and profiling radiometer measurements. Analysis of the measurements allowed the determination of macrophysical properties such as cirrus cloud height, ambient temperature, and geometrical depth, and optical characteristics were determined in terms of optical depth, extinction coefficient, and lidar ratio. Cirrus clouds were generally observed at heights ranging from 5.8 to 12.7 km, with a mean of 9.0±1.0 km. The mean cloud geometrical depth and optical depth were found to be 2.0±0.6 km and 0.350±0.311, respectively. Optical depth increased linearly with increasing geometrical depth. The results derived from lidar signals showed that cirrus over SACOL consisted of thin cirrus and opaque cirrus which occurred frequently in the height of 8–10 km. The lidar ratio varied from 5 to 70 sr, with a mean value of 26±16 sr, after taking into account multiple scattering effects. The mean lidar ratio of thin cirrus was greater than that of opaque cirrus. The maximum lidar ratio appeared between 0.058 and 0.3 when plotted against optical depth. The lidar ratio increased exponentially as the optical depth increased. The maximum lidar ratio fell between 11 and 12 km when plotted against cloud mid-height. The lidar ratio first increased and then decreased with increasing mid-height. -- Highlights: ► Cirrus clouds over semi-arid area were firstly observed by ground-based lidar. ► Macrophysical and optical characteristics of cirrus clouds were discussed. ► Thin cirrus and opaque cirrus occurred most frequently over SACOL. ► Thin cirrus often occurred above 10 km

  10. Micro-pulse upconversion Doppler lidar for wind and visibility detection in the atmospheric boundary layer.

    Science.gov (United States)

    Xia, Haiyun; Shangguan, Mingjia; Wang, Chong; Shentu, Guoliang; Qiu, Jiawei; Zhang, Qiang; Dou, Xiankang; Pan, Jianwei

    2016-11-15

    For the first time, to the best of our knowledge, a compact, eye-safe, and versatile direct detection Doppler lidar is developed using an upconversion single-photon detection method at 1.5 μm. An all-fiber and polarization maintaining architecture is realized to guarantee the high optical coupling efficiency and the robust stability. Using integrated-optic components, the conservation of etendue of the optical receiver is achieved by manufacturing a fiber-coupled periodically poled lithium niobate waveguide and an all-fiber Fabry-Perot interferometer (FPI). The double-edge technique is implemented by using a convert single-channel FPI and a single upconversion detector, incorporating a time-division multiplexing method. The backscatter photons at 1548.1 nm are converted into 863 nm via mixing with a pump laser at 1950 nm. The relative error of the system is less than 0.1% over nine weeks. In experiments, atmospheric wind and visibility over 48 h are detected in the boundary layer. The lidar shows good agreement with the ultrasonic wind sensor, with a standard deviation of 1.04 m/s in speed and 12.3° in direction.

  11. Micro-pulse polarization lidar at 1.5  μm using a single superconducting nanowire single-photon detector.

    Science.gov (United States)

    Qiu, Jiawei; Xia, Haiyun; Shangguan, Mingjia; Dou, Xiankang; Li, Manyi; Wang, Chong; Shang, Xiang; Lin, Shengfu; Liu, Jianjiang

    2017-11-01

    An all-fiber, eye-safe and micro-pulse polarization lidar is demonstrated with a polarization-maintaining structure, incorporating a single superconducting nanowire single-photon detector (SNSPD) at 1.5 μm. The time-division multiplexing technique is used to achieve a calibration-free optical layout. A single piece of detector is used to detect the backscatter signals at two orthogonal states in an alternative sequence. Thus, regular calibration of the two detectors in traditional polarization lidars is avoided. The signal-to-noise ratio of the lidar is guaranteed by using an SNSPD, providing high detection efficiency and low dark count noise. The linear depolarization ratio (LDR) of the urban aerosol is observed horizontally over 48 h in Hefei [N31°50'37'', E117°15'54''], when a heavy air pollution is spreading from the north to the central east of China. Phenomena of LDR bursts are detected at a location where a building is under construction. The lidar results show good agreement with the data detected from a sun photometer, a 532 nm visibility lidar, and the weather forecast information.

  12. Ground-based eye-safe networkable micro-pulse differential absorption and high spectral resolution lidar for water vapor and aerosol profiling in the lower troposphere

    Science.gov (United States)

    Repasky, K. S.; Spuler, S.; Hayman, M. M.; Bunn, C. E.

    2017-12-01

    Atmospheric water vapor is a greenhouse gas that is known to be a significant driver of weather and climate. Several National Research Council (NRC) reports have highlighted the need for improved water vapor measurements that can capture its spatial and temporal variability as a means to improve weather predictions. Researchers at Montana State University (MSU) and the National Center for Atmospheric Research (NCAR) have developed an eye-safe diode laser based micro-pulse differential absorption lidar (MP-DIAL) for water vapor profiling in the lower troposphere. The MP-DIAL is capable of long term unattended operation and is capable of monitoring water vapor in the lower troposphere in most weather conditions. Two MP-DIAL instruments are currently operational and have been deployed at the Front Range Air Pollution and Photochemistry Experiment (FRAPPE), the Plains elevated Convection at Night (PECAN) experiment, the Perdigão experiment, and the Land Atmosphere Feedback Experiment (LAFE). For each of these field experiments, the MP-DIAL was run unattended and provided near-continuous water vapor profiles, including periods of bright daytime clouds, from 300 m above the ground level to 4 km (or the cloud base) with 150 m vertical resolution and 5 minute temporal resolution. Three additional MP-DIAL instruments are currently under construction and will result in a network of five eye-safe MP-DIAL instruments for ground based weather and climate research experiments. Taking advantage of the broad spectral coverage and modularity or the diode based architecture, a high spectral resolution lidar (HSRL) measurement capabilities was added to the second MP-DIAL instrument. The HSRL capabilities will be operational during the deployment at the LAFE field experiment. The instrument architecture will be presented along with examples of data collected during recent field experiments.

  13. Cloud properties derived from two lidars over the ARM SGP site

    Energy Technology Data Exchange (ETDEWEB)

    Dupont, Jean-Charles; Haeffelin, Martial; Morille, Y.; Comstock, Jennifer M.; Flynn, Connor J.; Long, Charles N.; Sivaraman, Chitra; Newsom, Rob K.

    2011-02-16

    [1] Active remote sensors such as lidars or radars can be used with other data to quantify the cloud properties at regional scale and at global scale (Dupont et al., 2009). Relative to radar, lidar remote sensing is sensitive to very thin and high clouds but has a significant limitation due to signal attenuation in the ability to precisely quantify the properties of clouds with a 20 cloud optical thickness larger than 3. In this study, 10-years of backscatter lidar signal data are analysed by a unique algorithm called STRucture of ATmosphere (STRAT, Morille et al., 2007). We apply the STRAT algorithm to data from both the collocated Micropulse lidar (MPL) and a Raman lidar (RL) at the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site between 1998 and 2009. Raw backscatter lidar signal is processed and 25 corrections for detector deadtime, afterpulse, and overlap are applied. (Campbell et al.) The cloud properties for all levels of clouds are derived and distributions of cloud base height (CBH), top height (CTH), physical cloud thickness (CT), and optical thickness (COT) from local statistics are compared. The goal of this study is (1) to establish a climatology of macrophysical and optical properties for all levels of clouds observed over the ARM SGP site 30 and (2) to estimate the discrepancies induced by the two remote sensing systems (pulse energy, sampling, resolution, etc.). Our first results tend to show that the MPLs, which are the primary ARM lidars, have a distinctly limited range where all of these cloud properties are detectable, especially cloud top and cloud thickness, but even actual cloud base especially during summer daytime period. According to the comparisons between RL and MPL, almost 50% of situations show a signal to noise ratio too low (smaller than 3) for the MPL in order to detect clouds higher than 7km during daytime period in summer. Consequently, the MPLderived annual cycle of cirrus cloud base (top) altitude is

  14. Deploying scanning lidars at coastal sites

    DEFF Research Database (Denmark)

    Courtney, Michael; Simon, Elliot

    that the most desirable sites are away from sand dunes and with some significant elevation above the sea surface, such as at the top of a cliff. Coastal planning restrictions in Denmark are quite restrictive and it was important to allow sufficient time to obtain permission from the relevant authorities....... At the same time, with our particular application, the authorities and land owners were quite favourably inclined to give permission to temporary installations in support of wind energy research. The report concludes with the final positions and a pictorial description of the three RUNE scanning lidars....

  15. Lidar Inter-Comparison Exercise Final Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Protat, A [Australian Bureau of Meterology; Young, S

    2015-02-01

    The objective of this field campaign was to evaluate the performance of the new Leosphere R-MAN 510 lidar, procured by the Australian Bureau of Meteorology, by testing it against the MicroPulse Lidar (MPL) and Raman lidars, at the Darwin Atmospheric Radiation Measurement (ARM) site. This lidar is an eye-safe (355 nm), turn-key mini Raman lidar, which allows for the detection of aerosols and cloud properties, and the retrieval of particulate extinction profiles. To accomplish this evaluation, the R-MAN 510 lidar has been operated at the Darwin ARM site, next to the MPL, Raman lidar, and Vaisala ceilometer (VCEIL) for three months (from 20 January 2013 to 20 April 2013) in order to collect a sufficient sample size for statistical comparisons.

  16. A Ground-Based Doppler Radar and Micropulse Lidar Forward Simulator for GCM Evaluation of Arctic Mixed-Phase Clouds: Moving Forward Towards an Apples-to-apples Comparison of Hydrometeor Phase

    Science.gov (United States)

    Lamer, K.; Fridlind, A. M.; Ackerman, A. S.; Kollias, P.; Clothiaux, E. E.

    2017-12-01

    An important aspect of evaluating Artic cloud representation in a general circulation model (GCM) consists of using observational benchmarks which are as equivalent as possible to model output in order to avoid methodological bias and focus on correctly diagnosing model dynamical and microphysical misrepresentations. However, current cloud observing systems are known to suffer from biases such as limited sensitivity, and stronger response to large or small hydrometeors. Fortunately, while these observational biases cannot be corrected, they are often well understood and can be reproduced in forward simulations. Here a ground-based millimeter wavelength Doppler radar and micropulse lidar forward simulator able to interface with output from the Goddard Institute for Space Studies (GISS) ModelE GCM is presented. ModelE stratiform hydrometeor fraction, mixing ratio, mass-weighted fall speed and effective radius are forward simulated to vertically-resolved profiles of radar reflectivity, Doppler velocity and spectrum width as well as lidar backscatter and depolarization ratio. These forward simulated fields are then compared to Atmospheric Radiation Measurement (ARM) North Slope of Alaska (NSA) ground-based observations to assess cloud vertical structure (CVS). Model evalution of Arctic mixed-phase cloud would also benefit from hydrometeor phase evaluation. While phase retrieval from synergetic observations often generates large uncertainties, the same retrieval algorithm can be applied to observed and forward-simulated radar-lidar fields, thereby producing retrieved hydrometeor properties with potentially the same uncertainties. Comparing hydrometeor properties retrieved in exactly the same way aims to produce the best apples-to-apples comparisons between GCM ouputs and observations. The use of a comprenhensive ground-based forward simulator coupled with a hydrometeor classification retrieval algorithm provides a new perspective for GCM evaluation of Arctic mixed

  17. Lidar Remote Sensing for Industry and Environment Monitoring

    Science.gov (United States)

    Singh, Upendra N. (Editor); Itabe, Toshikazu (Editor); Sugimoto, Nobuo (Editor)

    2000-01-01

    Contents include the following: 1. Keynote paper: Overview of lidar technology for industrial and environmental monitoring in Japan. 2. lidar technology I: NASA's future active remote sensing mission for earth science. Geometrical detector consideration s in laser sensing application (invited paper). 3. Lidar technology II: High-power femtosecond light strings as novel atmospheric probes (invited paper). Design of a compact high-sensitivity aerosol profiling lidar. 4. Lasers for lidars: High-energy 2 microns laser for multiple lidar applications. New submount requirement of conductively cooled laser diodes for lidar applications. 5. Tropospheric aerosols and clouds I: Lidar monitoring of clouds and aerosols at the facility for atmospheric remote sensing (invited paper). Measurement of asian dust by using multiwavelength lidar. Global monitoring of clouds and aerosols using a network of micropulse lidar systems. 6. Troposphere aerosols and clouds II: Scanning lidar measurements of marine aerosol fields at a coastal site in Hawaii. 7. Tropospheric aerosols and clouds III: Formation of ice cloud from asian dust particles in the upper troposphere. Atmospheric boundary layer observation by ground-based lidar at KMITL, Thailand (13 deg N, 100 deg. E). 8. Boundary layer, urban pollution: Studies of the spatial correlation between urban aerosols and local traffic congestion using a slant angle scanning on the research vessel Mirai. 9. Middle atmosphere: Lidar-observed arctic PSC's over Svalbard (invited paper). Sodium temperature lidar measurements of the mesopause region over Syowa Station. 10. Differential absorption lidar (dIAL) and DOAS: Airborne UV DIAL measurements of ozone and aerosols (invited paper). Measurement of water vapor, surface ozone, and ethylene using differential absorption lidar. 12. Space lidar I: Lightweight lidar telescopes for space applications (invited paper). Coherent lidar development for Doppler wind measurement from the International Space

  18. Status of the NASA Micro Pulse Lidar Network (MPLNET: overview of the network and future plans, new version 3 data products, and the polarized MPL

    Directory of Open Access Journals (Sweden)

    Welton Ellsworth J.

    2018-01-01

    Full Text Available The NASA Micro Pulse Lidar Network (MPLNET is a global federated network of Micro-Pulse Lidars (MPL co-located with the NASA Aerosol Robotic Network (AERONET. MPLNET began in 2000, and there are currently 17 long-term sites, numerous field campaigns, and more planned sites on the way. We have developed a new Version 3 processing system including the deployment of polarized MPLs across the network. Here we provide an overview of Version 3, the polarized MPL, and current and future plans.

  19. Status of the NASA Micro Pulse Lidar Network (MPLNET): overview of the network and future plans, new version 3 data products, and the polarized MPL

    Science.gov (United States)

    Welton, Ellsworth J.; Stewart, Sebastian A.; Lewis, Jasper R.; Belcher, Larry R.; Campbell, James R.; Lolli, Simone

    2018-04-01

    The NASA Micro Pulse Lidar Network (MPLNET) is a global federated network of Micro-Pulse Lidars (MPL) co-located with the NASA Aerosol Robotic Network (AERONET). MPLNET began in 2000, and there are currently 17 long-term sites, numerous field campaigns, and more planned sites on the way. We have developed a new Version 3 processing system including the deployment of polarized MPLs across the network. Here we provide an overview of Version 3, the polarized MPL, and current and future plans.

  20. Wide Angle Imaging Lidar (WAIL): Theory of Operation and Results from Cross-Platform Validation at the ARM Southern Great Plains Site

    Science.gov (United States)

    Polonsky, I. N.; Davis, A. B.; Love, S. P.

    2004-05-01

    WAIL was designed to determine physical and geometrical characteristics of optically thick clouds using the off-beam component of the lidar return that can be accurately modeled within the 3D photon diffusion approximation. The theory shows that the WAIL signal depends not only on the cloud optical characteristics (phase function, extinction and scattering coefficients) but also on the outer thickness of the cloud layer. This makes it possible to estimate the mean optical and geometrical thicknesses of the cloud. The comparison with Monte Carlo simulation demonstrates the high accuracy of the diffusion approximation for moderately to very dense clouds. During operation WAIL is able to collect a complete data set from a cloud every few minutes, with averaging over horizontal scale of a kilometer or so. In order to validate WAIL's ability to deliver cloud properties, the LANL instrument was deployed as a part of the THickness from Off-beam Returns (THOR) validation IOP. The goal was to probe clouds above the SGP CART site at night in March 2002 from below (WAIL and ARM instruments) and from NASA's P3 aircraft (carrying THOR, the GSFC counterpart of WAIL) flying above the clouds. The permanent cloud instruments we used to compare with the results obtained from WAIL were ARM's laser ceilometer, micro-pulse lidar (MPL), millimeter-wavelength cloud radar (MMCR), and micro-wave radiometer (MWR). The comparison shows that, in spite of an unusually low cloud ceiling, an unfavorable observation condition for WAIL's present configuration, cloud properties obtained from the new instrument are in good agreement with their counterparts obtained by other instruments. So WAIL can duplicate, at least for single-layer clouds, the cloud products of the MWR and MMCR together. But WAIL does this with green laser light, which is far more representative than microwaves of photon transport processes at work in the climate system.

  1. Fluorescence lidar measurements at the archaeological site House of Augustus at Palatino, Rome

    Science.gov (United States)

    Raimondi, Valentina; Alisi, Chiara; Barup, Kerstin; Bracciale, Maria Paola; Broggi, Alessandra; Conti, Cinzia; Hällström, Jenny; Lognoli, David; Palombi, Lorenzo; Santarelli, Maria Laura; Sprocati, Anna Rosa

    2013-10-01

    Early diagnostics and documentation fulfill an essential role for an effective planning of conservation and restoration of cultural heritage assets. In particular, remote sensing techniques that do not require the use of scaffolds or lifts, such as fluoresence lidar, can provide useful information to obtain an overall assessment of the status of the investigated surfaces and can be exploited to address analytical studies in selected areas. Here we present the results of a joint Italian-Swedish project focused on documenting and recording the status of some sections of the part closed to the public by using fluorescence hyperspectral imaging lidar. The lidar used a tripled-frequency Nd:YAG laser emitting at 355 nm as excitation source and an intensified, gated 512x512-pixel CCD as detector. The lidar had imaging capabilities thanks to a computer-controlled scanning mirror. The fluorescence characteristics of fresco wall paintings were compared to those of fresco fragments found at the same archaeological site and separately examined in the lab using FT-IR and Raman techniques for the identification of pigments. The fluorescence lidar was also used to remotely detect the growth of phototrophic biodeteriogens on the walls. The fluorescence lidar data were compared with results from biological sampling, cultivation and laboratory analysis by molecular techniques.

  2. Airborne Lidar Measurements of Aerosol Optical Properties During SAFARI-2000

    Science.gov (United States)

    McGill, M. J.; Hlavka, D. L.; Hart, W. D.; Welton, E. J.; Campbell, J. R.; Starr, David OC. (Technical Monitor)

    2002-01-01

    The Cloud Physics Lidar (CPL) operated onboard the NASA ER-2 high altitude aircraft during the SAFARI-2000 field campaign. The CPL provided high spatial resolution measurements of aerosol optical properties at both 1064 nm and 532 nm. We present here results of planetary boundary layer (PBL) aerosol optical depth analysis and profiles of aerosol extinction. Variation of optical depth and extinction are examined as a function of regional location. The wide-scale aerosol mapping obtained by the CPL is a unique data set that will aid in future studies of aerosol transport. Comparisons between the airborne CPL and ground-based MicroPulse Lidar Network (MPL-Net) sites are shown to have good agreement.

  3. Development of LiDAR measurements for the German offshore test site

    International Nuclear Information System (INIS)

    Rettenmeier, A; Kuehn, M; Waechter, M; Rahm, S; Mellinghoff, H; Siegmeier, B; Reeder, L

    2008-01-01

    The paper introduces the content of the recently started joint research project 'Development of LiDAR measurements for the German Offshore Test Site' which has the objective to support other research projects at the German offshore test site 'alpha ventus'. The project has started before the erection of the offshore wind farm and one aim is to give recommendations concerning LiDAR technology useable for offshore measurement campaigns and data analysis. The work is organized in four work packages. The work package LiDAR technology deals with the specification, acquisition and calibration of a commercial LiDAR system for the measurement campaigns. Power curve measurements are dedicated to power curve assessment with ground-based LiDAR using standard statistical methods. Additionally, it deals with the development of new methods for the measurement of non-steady short-term power curves. Wind field research aims at the development of wake loading simulation methods of wind turbines and the exploration of loading control strategies and nacelle-based wind field measurement techniques. Finally, dissemination of results to the industry takes place in work package Technology transfer

  4. Lidar to lidar calibration phase 2

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Courtney, Michael

    This report presents the results from phase 2 of a lidar to lidar (L2L) calibration procedure. Phase two of the project included two measurement campaigns conducted at given sites. The purpose was to find out if the lidar-to-lidar calibration procedure can be conducted with similar results...

  5. Lidar Cloud Detection with Fully Convolutional Networks

    Science.gov (United States)

    Cromwell, E.; Flynn, D.

    2017-12-01

    The vertical distribution of clouds from active remote sensing instrumentation is a widely used data product from global atmospheric measuring sites. The presence of clouds can be expressed as a binary cloud mask and is a primary input for climate modeling efforts and cloud formation studies. Current cloud detection algorithms producing these masks do not accurately identify the cloud boundaries and tend to oversample or over-represent the cloud. This translates as uncertainty for assessing the radiative impact of clouds and tracking changes in cloud climatologies. The Atmospheric Radiation Measurement (ARM) program has over 20 years of micro-pulse lidar (MPL) and High Spectral Resolution Lidar (HSRL) instrument data and companion automated cloud mask product at the mid-latitude Southern Great Plains (SGP) and the polar North Slope of Alaska (NSA) atmospheric observatory. Using this data, we train a fully convolutional network (FCN) with semi-supervised learning to segment lidar imagery into geometric time-height cloud locations for the SGP site and MPL instrument. We then use transfer learning to train a FCN for (1) the MPL instrument at the NSA site and (2) for the HSRL. In our semi-supervised approach, we pre-train the classification layers of the FCN with weakly labeled lidar data. Then, we facilitate end-to-end unsupervised pre-training and transition to fully supervised learning with ground truth labeled data. Our goal is to improve the cloud mask accuracy and precision for the MPL instrument to 95% and 80%, respectively, compared to the current cloud mask algorithms of 89% and 50%. For the transfer learning based FCN for the HSRL instrument, our goal is to achieve a cloud mask accuracy of 90% and a precision of 80%.

  6. Development of an Airborne Micropulse Water Vapor DIAL

    Science.gov (United States)

    Nehrir, A. R.; Ismail, S.

    2012-12-01

    Water vapor plays a key role in many atmospheric processes affecting both weather and climate. Airborne measurements of tropospheric water vapor profiles have been a longstanding observational need to not only the active remote sensing community but also to the meteorological, weather forecasting, and climate/radiation science communities. Microscale measurements of tropospheric water vapor are important for enhancing near term meteorological forecasting capabilities while mesoscale and synopticscale measurements can lead to an enhanced understanding of the complex coupled feedback mechanisms between water vapor, temperature, aerosols, and clouds. To realize tropospheric measurements of water vapor profiles over the microscale-synopticscale areas of meteorological interest, a compact and cost effective airborne micropulse differential absorption lidar (DIAL) is being investigated using newly emerging semiconductor based laser technology. Ground based micropulse DIAL (MPD) measurements of tropospheric water vapor and aerosol profiles up to 6 km and 15 km, respectively, have been previously demonstrated using an all semiconductor based laser transmitter. The DIAL transmitter utilizes a master oscillator power amplifier (MOPA) configuration where two semiconductor seed lasers are used to seed a single pass traveling wave tapered semiconductor optical amplifier (TSOA), producing up to 7μJ pulse energies over a 1 μs pulse duration at a 10 kHz pulse repetition frequency (PRF). Intercomparisons between the ground based instrument measurements and radiosonde profiles demonstrating the MPD performance under varying atmospheric conditions will be presented. Work is currently ongoing to expand upon the ground based MPD concept and to develop a compact and cost effective system capable of deployment on a mid-low altitude aircraft such as the NASA Langley B200 King Air. Initial lab experiments show that a two-three fold increase in the laser energy compared to the ground

  7. Lidar Comparison for GoAmazon 2014/15 Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Henrique MJ [Universidade de Sao Paulo; Barja, B [Universidade de Sao Paulo; Landulfo, E [Universidade de Sao Paulo

    2016-04-01

    The Observations and Modeling of the Green Ocean Amazon 2014/15 (GoAmazon 2014/15) experiment uses the city of Manaus, Amazonas (AM), Brazil, in the setting of the surrounding green ocean as a natural laboratory for understanding the effects of present and future anthropogenic pollution on the aerosol and cloud life cycle in the tropics. The U.S. Department of Energy (DOE) supported this experiment through the deployment of the Atmospheric Radiation Measurement (ARM) Climate Research Facility’s first Mobile Facility (AMF-1) in the city of Manacapuru, which is 100 km downwind of Manaus, from January 1 2014 to December 31 2015. During the second Intensive Operational Period (IOP) from August 15 to October 15 2014, three lidar systems were operated simultaneously at different experimental sites, and an instrument comparison campaign was carried out during the period October 4 to 10, during which the mobile lidar system from Instituto de Pesquisas Energéticas e Nucleares-Universidade de São Paulo was brought from the T2 site (Iranduba) to the other sites (T3 [Manacapuru] and then T0e-Embrapa). In this report we present the data collected by the mobile lidar system at the DOE-ARM site and compare its measurements with those from the micro-pulse lidar system running at that site.

  8. Industrial site particulate pollution monitoring with an eye-safe and scanning industrial fiber lidar

    Science.gov (United States)

    Belanger, Brigitte; Fougeres, Andre; Talbot, Mario

    2001-02-01

    12 Over the past few years, INO has developed an Industrial Fiber Lidar (IFL). It enables the particulate pollution monitoring on industrial sites. More particularly, it has been used to take measurements of particulate concentration at Port Facilities of an aluminum plant during boat unloading. It is an eye-safe and portable lidar. It uses a fiber laser also developed at INO emitting 1.7 microJoules at 1534 nm with a pulse repetition frequency of 5 kHz. Given the harsh environment of an industrial site, all the sensitive equipment like the laser source, detector, computer and acquisition electronics are located in a building and connected to the optical module, placed outside, via optical fibers up to 500 m long. The fiber link also offers all the flexibility for placing the optical module at a proper location. The optical module is mounted on a two axis scanning platform, able to perform an azimuth scan of 0 to 355 deg and an elevation scan of +/- 90 deg, which enables the scanning of zones defined by the user. On this industrial site, materials like bauxite, alumina, spathfluor and calcined coke having mass extinction coefficients ranging from 0.53 to 2.7 m2/g can be detected. Data for different measurement configurations have been obtained. Concentration values have been calculated for measurements in a hopper, along a wharf and over the urban area close to the port facilities. The lidar measurements have been compared to high volume samplers. Based on these comparisons, it has been established that the IFL is able to monitor the relative fluctuations of dust concentrations. It can be integrated to the process control of the industrial site for alarm generation when concentrations are above threshold.

  9. Two years of wind-lidar measurements at an Italian Mediterranean Coastal Site

    DEFF Research Database (Denmark)

    Gullí, D.; Avolio, E.; Calidonna, C. R.

    2017-01-01

    Reliable measurements of vertical profiles of wind speed and direction are needed for testing models and methodologies of use for wind energy assessment. In particular, modelling complex terrain such as coastal areas is challenging due to the coastal discontinuity that is not accurately resolved...... in mesoscale numerical model. Here, we present a unique database from a coastal site in South Italy (middle of the Mediterranean area) where vertical profiles of wind speed and direction have been collected during a two-year period from a wind-lidar ZEPHIR-300® at a coastal-suburban area. We show an overview...

  10. THE NEW THREE-DIMENSIONAL VISUALIZATION METHOD OF HERITAGE SITES BY LIDAR DATA

    Directory of Open Access Journals (Sweden)

    N. Fujii

    2012-07-01

    Full Text Available We introduce a new visualization method for the three dimensional data with laser scanning from helicopter to express of the detailed landscape with "Red Relief Image Map (RRIM"and "3D-Viewer". This RRIM and 3D-Viewer’s method effectively represent 3D topographic information without any additional devices and stereopsis ability for the audience only through two dimensional medium and shows an appropriate form of every feature in the site. Chapters present what the laser scanning from helicopter is and show some examples of mounded tombs with RRIM and 3D-Viewer. This visualization technique including detailed topographical information and geographical coordinates can be directly linked to CAD and GIS system, therefore the LiDAR can easily produce a contour line, a cross section and a bird's-eye view at any place as well as measure the height of trees. This is different from other 3D topographic image with a shadow effect. Vegetation on the site is no longer obstacle to get detailed topographical information. Therefore, in Japan, this method is useful for huge mounded tombs thickly covered with trees, especially "Ryo-bo (imperial tomb"which are administrated by the Imperial Household Agency and common people can't enter. Also a cluster of small mounded tombs which extend in the vast area called "Gunshufun" is shown effectively for the location of each mounded tomb. This method is suitable for understanding the structure of the sites in any wide spread archaeological fields. Moreover, in the management of heritages it is important that these data present precise information of the surface of lands to understand the present situation of heritages. Detailed topographical information by "LiDAR and Red Relief Image Map and 3DViewer" will open a new gate for managing of cultural heritage sites in the future.

  11. Characteristics of Volcanic Stratospheric Aerosol Layer Observed by CALIOP and Ground Based Lidar at Equatorial Atmosphere Radar Site

    Science.gov (United States)

    Abo, Makoto; Shibata, Yasukuni; Nagasawa, Chikao

    2018-04-01

    We investigated the relation between major tropical volcanic eruptions in the equatorial region and the stratospheric aerosol data, which have been collected by the ground based lidar observations at at Equatorial Atmosphere Radar site between 2004 and 2015 and the CALIOP observations in low latitude between 2006 and 2015. We found characteristic dynamic behavior of volcanic stratospheric aerosol layers over equatorial region.

  12. Evaluation of Terrestrial LIDAR for Monitoring Geomorphic Change at Archeological Sites in Grand Canyon National Park, Arizona

    Science.gov (United States)

    Collins, Brian D.; Brown, Kristin M.; Fairley, Helen C.

    2008-01-01

    This report presents the results of an evaluation of terrestrial light detection and ranging (LIDAR) for monitoring geomorphic change at archeological sites located within Grand Canyon National Park, Ariz. Traditionally, topographic change-detection studies have used total station methods for the collection of data related to key measurable features of site erosion such as the location of thalwegs and knickpoints of gullies that traverse archeological sites (for example, Pederson and others, 2003). Total station methods require survey teams to walk within and on the features of interest within the archeological sites to take accurate measurements. As a result, site impacts may develop such as trailing, damage to cryptogamic crusts, and surface compaction that can exacerbate future erosion of the sites. National Park Service (NPS) resource managers have become increasingly concerned that repeated surveys for research and monitoring purposes may have a detrimental impact on the resources that researchers are trying to study and protect. Beginning in 2006, the Sociocultural Program of the U.S. Geological Survey's (USGS) Grand Canyon Monitoring and Research Center (GCMRC) initiated an evaluation of terrestrial LIDAR as a new monitoring tool that might enhance data quality and reduce site impacts. This evaluation was conducted as one part of an ongoing study to develop objective, replicable, quantifiable monitoring protocols for tracking the status and trend of variables affecting archeological site condition along the Colorado River corridor. The overall study consists of two elements: (1) an evaluation of the methodology through direct comparison to geomorphologic metrics already being collected by total station methods (this report) and (2) an evaluation of terrestrial LIDAR's ability to detect topographic change through the collection of temporally different datasets (a report on this portion of the study is anticipated early in 2009). The main goals of the first

  13. Lidar to lidar calibration

    DEFF Research Database (Denmark)

    Fernandez Garcia, Sergio; Villanueva, Héctor

    This report presents the result of the lidar to lidar calibration performed for ground-based lidar. Calibration is here understood as the establishment of a relation between the reference lidar wind speed measurements with measurement uncertainties provided by measurement standard and corresponding...... lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from the reference lidar measurements are given for information only....

  14. Micropulse diode laser trabeculoplasty -- 180-degree treatment.

    Science.gov (United States)

    Rantala, Elina; Välimäki, Juha

    2012-08-01

    To evaluate the outcome of 180° micropulse diode laser trabeculoplasty (MDLT) in patients with open-angle glaucoma. A retrospective review of 40 eyes of 29 MDLT-treated patients with a minimum follow-up time of 6 months. Successful outcome was defined as follows: (i) a ≥20% or (ii) a ≥3-mmHg decrease of intraocular pressure (IOP), no further need for laser- or incisional surgery and the number of glaucoma medication was the same or less than preoperative. These definitions will from now on be referred to as definition one and definition two. Life-table analysis showed an overall success rate of 2.5% (1/40) and 7.5% (3/40) (according to definitions one and two, respectively) after up to 19 months of follow-up. The average time for failure was by definition one 2.9 months (standard deviation, SD ± 3.5, range 1-12 months) and by definition two 3.3 months (SD ± 3.9, range 1-16 months). There were no intra- or postoperative complications caused by MDLT. Postoperative inflammatory reaction, cells and flare, was scanty. Our results suggest that 180° MDLT is a safe but ineffective treatment in patients with open-angle glaucoma. © 2010 The Authors. Acta Ophthalmologica © 2010 Acta Ophthalmologica Scandinavica Foundation.

  15. Tenneco and Greenwood Islands Disposal Sites (Mississippi) 2004 Lidar Coverage, USACE National Coastal Mapping Program

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — The Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) has performed a coastal survey along the Gulf of Mexico coastline of MS in 2004. The data...

  16. Measurements at FP3 in support of pecan scientific objectives using MPL-111 lidar

    Directory of Open Access Journals (Sweden)

    Pozsonyi Kristen

    2018-01-01

    Full Text Available This paper will report on the data collected by a Sigma Space Micropulse Lidar (MPL-111, and how these measurements, when integrated with other data, helps to inform our analysis of two cases of the Great Plains nocturnal Low-Level Jet (LLJ in the vicinity of FP3.

  17. Measurements at FP3 in support of pecan scientific objectives using MPL-111 lidar

    Science.gov (United States)

    Pozsonyi, Kristen; Midzak, Natalie; Prestine, Christina; Clark, Richard

    2018-04-01

    This paper will report on the data collected by a Sigma Space Micropulse Lidar (MPL-111), and how these measurements, when integrated with other data, helps to inform our analysis of two cases of the Great Plains nocturnal Low-Level Jet (LLJ) in the vicinity of FP3.

  18. Monitoring and Quantifying Particles Emissions around Industrial Sites with Scanning Doppler Lidar

    Science.gov (United States)

    Thobois, L.; Royer, P.; Parmentier, R.; Brooks, M.; Knoepfle, A.; Alexander, J.; Stidwell, P.; Kumar, R.

    2018-04-01

    Scanning Coherent Doppler Lidars have been used over the last decade for measuring wind for applications in wind energy [1], meteorology [2] and aviation [3]. They allow for accurate measurements of wind speeds up to a distance of 10 km based on the Doppler shift effect of aerosols. The signal reflectivity (CNR or Carrier-to-Noise Ratio) profiles can also be retrieved from the strength of the Lidar signal. In this study, we will present the developments of algorithm for retrieving aerosol optical properties like the relative attenuated backscatter coefficient and the mass concentration of particles. The use of these algorithms during one operational trial in Point Samson, Western Australia to monitor fugitive emissions over a mine will be presented. This project has been initiated by the Australian Department of Environment Regulations to better determine the impact of the Port on the neighboring town. During the trial in Summer, the strong impact of turbulence refractive index on Lidar performances has been observed. Multiple methodologies have been applied to reduce this impact with more or less success. At the end, a dedicated setup and configuration have been established that allow to properly observe the plumes of the mine with the scanning Lidar. The Lidar data has also been coupled to beta attenuation in-situ sensors for retrieving mass concentration maps. A few case of dispersion of plumes will be presented showing the necessity to combine both the wind and aerosol data.

  19. Scanning elastic lidar observations of aerosol transport in New York City

    Science.gov (United States)

    Diaz, Adrian; Dominguez, Victor; Dobryansky, Selma; Wu, Yonghua; Arend, Mark; Vladutescu, Daniela Viviana; Gross, Barry; Moshary, Fred

    2018-04-01

    In this study, spatial distribution of aerosols in New York City is observed using a scanning eyesafe 532 nm elastic-backscatter micro-pulse lidar system. Observations show dynamics of the boundary layer and inhomogeneous distribution and transport of aerosols. The data acquired are complemented with simultaneous measurements of particulate matter and wind speed and direction. Furthermore, the system observations are validated by comparing them with a colocated multi-wavelength lidar.

  20. Application of lidars for assessment of wind conditions on a bridge site

    DEFF Research Database (Denmark)

    Jakobsen, J. B.; Cheynet, Etienne; Snæbjörnsson, Jonas

    2015-01-01

    Wind measurement techniques based on remote optical sensing, extensively applied in wind energy, have been exploited in civil engineering only in a limited number of studies. The present paper introduces a novel application of wind lidars in bridge engineering, and presents the findings from...... characterization. The paper presents a promising comparison of the measurements obtained by the three different sets of instruments, and discusses their complementary value....... the pilot measurement campaign on the Lysefjord Bridge in the South-West Norway. A single long-range pulsed WindScanner lidar and two short-range continuous-wave WindScanner lidars were deployed, in addition to five sonic anemometers installed on the bridge itself, the latter for long-term wind...

  1. Bent versus straight tips in micropulsed longitudinal phacoemulsification.

    Science.gov (United States)

    Stagg, Brian C; Gupta, Isha; Cahoon, Judd; Ronquillo, Cecinio; Shi, Dallas; Zaugg, Brian; Gardiner, Gareth; Barlow, William R; Pettey, Jeff H; Aabid Farukhi, M; Jensen, Jason; Olson, Randall J

    2015-10-01

    The aim of this study was to evaluate bent and straight phacoemulsification tips to determine which tip is more efficient in removal of lens fragments, using micropulsed longitudinal ultrasound in phacoemulsification. In vitro laboratory study. The John A. Moran Eye Center Laboratories, University of Utah, Salt Lake City, Utah, was the study setting. Pig lenses hardened in a manner comparable with dense human cataracts were cut into 2-mm cubes and removed with micropulsed longitudinal ultrasound using settings previously shown to be optimally efficient (6 milliseconds on and 6 milliseconds off for a bent tip). To verify this time as most efficient for a straight tip, we also tested times of 5, 6, and 7 milliseconds time on and off. The tips were either straight or with a 20-degree bend. Twenty cubes were used for each comparative run. For the straight tip, 6 milliseconds on (1.56 ± 0.815 seconds) was significantly more efficient than 7 milliseconds on (2.45 ± 1.56 seconds, p = 0.001) and not significantly more efficient than 5 milliseconds on (1.69 ± 0.86 seconds, p = 0.43). Five milliseconds off time (1.45 ± 0.76s) was more efficient than 6 milliseconds (2.06 ± 1.37 seconds, p = 0.004) and 7 milliseconds off (2.18 ± 1.24s, p = 0.001). The straight tip was more efficient than the bent tip (1.38 ± 0.83 versus 2.93 ± 2.14 seconds, p = 0.006). Results are contrary to accepted common belief. Micropulsed longitudinal phacoemulsification is more efficient with a straight rather than a bent tip. Copyright © 2015 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

  2. LiDAR, geophysical and field surveys at Ancient Epomanduodurum site and its surrounding country (Doubs, Eastern France)

    Science.gov (United States)

    Laplaige, Clement; Bossuet, Gilles; Thivet, Matthieu

    2010-05-01

    understand the connections, both in time and in space, between human occupation and the surrounding region, not only at the Roman period and the late Iron Age, but also during prehistoric, medieval and modern periods. In that way, we have defined a square window of 80 km², surrounding the Ancient site of Epomanduodurum This study is based on the LIDAR (Light Detection And Ranging) technology, particularly adapted for the detection and location of cultural resources (ancient fields, buried structures, graves) in forested environment and a multi-data crossing, including: - Geophysical prospecting (principally magnetic, electromagnetic and electric) - Studies of ancient maps, plans (18th and 19th) and archaeological inventories in order to spot the location of vestiges and the utilisation of former soils - Aerial and satellite picture analysis - Field walking and metal detector prospection in order to precise micro topographic anomalies obtained by LiDAR survey. We received first LiDAR results during August 2009 and the use of part of this data allows us to find new sites from different periods. We will present some results, mainly in an Ancient artisanal district built on a Latenian necropolis, on hilltop sites and also on mine plant.

  3. Ancient Maya Regional Settlement and Inter-Site Analysis: The 2013 West-Central Belize LiDAR Survey

    Directory of Open Access Journals (Sweden)

    Arlen F. Chase

    2014-09-01

    Full Text Available During April and May 2013, a total of 1057 km2 of LiDAR was flown by NCALM for a consortium of archaeologists working in West-central Belize, making this the largest surveyed area within the Mayan lowlands. Encompassing the Belize Valley and the Vaca Plateau, West-central Belize is one of the most actively researched parts of the Maya lowlands; however, until this effort, no comprehensive survey connecting all settlement had been conducted. Archaeological projects have investigated at least 18 different sites within this region. Thus, a large body of archaeological research provides both the temporal and spatial parameters for the varied ancient Maya centers that once occupied this area; importantly, these data can be used to help interpret the collected LiDAR data. The goal of the 2013 LiDAR campaign was to gain information on the distribution of ancient Maya settlement and sites on the landscape and, particularly, to determine how the landscape was used between known centers. The data that were acquired through the 2013 LiDAR campaign have significance for interpreting both the composition and limits of ancient Maya political units. This paper presents the initial results of these new data and suggests a developmental model for ancient Maya polities.

  4. Verification test for three WindCube WLS7 LiDARs at the Høvsøre test site

    DEFF Research Database (Denmark)

    Gottschall, Julia; Courtney, Michael

    The report describes the procedure of testing ground-based WindCube lidars (manufactured by the French company Leosphere) at the Høvsøre test site in comparison to reference sensors mounted at a meteorological mast. Results are presented for three tested units – in detail for unit WLS7-0062, and ......-0062, and in a summary for units WLS7-0064 and WLS7-0066. The verification test covers the evaluation of measured mean wind speeds, wind directions and wind speed standard deviations. The data analysis is basically performed in terms of different kinds of regression analyses.......The report describes the procedure of testing ground-based WindCube lidars (manufactured by the French company Leosphere) at the Høvsøre test site in comparison to reference sensors mounted at a meteorological mast. Results are presented for three tested units – in detail for unit WLS7...

  5. Elevation - LIDAR Survey - Roseau County, Minnesota

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — LIDAR Data for Roseau County Minnesota. This project consists of approximately 87 square miles of LIDAR mapping in Roseau County, Minnesota at two sites: area 1,...

  6. Cloud Physics Lidar Measurements During the SAFARI-2000 Field Campaign

    Science.gov (United States)

    McGill, Matthew; Hlavka, Dennis; Hart, William; Spinhirne, James; Scott, Stan; Starr, David OC. (Technical Monitor)

    2001-01-01

    A new remote sensing instrument, the Cloud Physics Lidar (CPL) has been built for use on the ER-2 aircraft. The first deployment for CPL was the SAFARI-2000 field campaign during August-September 2000. The CPL is a three-wavelength lidar designed for studies of cirrus, subvisual cirrus, and boundary layer aerosols. The CPL utilizes a high repetition rate, low pulse energy laser with photon counting detectors. A brief description of the CPL instrument will be given, followed by examples of CPL data products. In particular, examples of aerosol backscatter, including boundary layer smoke and cirrus clouds will be shown. Resulting optical depth estimates derived from the aerosol measurements will be shown. Comparisons of the CPL optical depth and optical depth derived from microPulse Lidar and the AATS-14 sunphotomer will be shown.

  7. A Micropulse eye-safe all-fiber molecular backscatter coherent temperature lidar

    DEFF Research Database (Denmark)

    Abari, Cyrus F.; Chu, Xinzhao; Mann, Jakob

    2016-01-01

    resolution spectrum in the baseband can be acquired. Due to the presence of a structured spectra resulting from the spontaneous Rayleigh-Brillouine scattering, associated with the relevant operating regimes, an accurate estimation of the temperature can be carried out. One of the main advantages...

  8. Weibull Wind-Speed Distribution Parameters Derived from a Combination of Wind-Lidar and Tall-Mast Measurements Over Land, Coastal and Marine Sites

    DEFF Research Database (Denmark)

    Gryning, Sven-Erik; Floors, Rogier Ralph; Peña, Alfredo

    2016-01-01

    Wind-speed observations from tall towers are used in combination with observations up to 600 m in altitude from a Doppler wind lidar to study the long-term conditions over suburban (Hamburg), rural coastal (Høvsøre) and marine (FINO3) sites. The variability in the wind field among the sites is ex...... of the vertical profile of the shape parameter fits well with observations over land, coastal regions and over the sea. An applied model for the dependence of the reversal height on the surface roughness is in good agreement with the observations over land....

  9. Mapping elevations of tidal wetland restoration sites in San Francisco Bay: Comparing accuracy of aerial lidar with a singlebeam echosounder

    Science.gov (United States)

    Athearn, N.D.; Takekawa, John Y.; Jaffe, B.; Hattenbach, B.J.; Foxgrover, A.C.

    2010-01-01

    The southern edge of San Francisco Bay is surrounded by former salt evaporation ponds, where tidal flow has been restricted since the mid to late 1890s. These ponds are now the focus of a large wetland restoration project, and accurate measurement of current pond bathymetry and adjacent mud flats has been critical to restoration planning. Aerial light detection and ranging (lidar) has become a tool for mapping surface elevations, but its accuracy had rarely been assessed for wetland habitats. We used a singlebeam echosounder system we developed for surveying shallow wetlands to map submerged pond bathymetry in January of 2004 and compared those results with aerial lidar surveys in two ponds that were dry in May of 2004. From those data sets, we compared elevations for 5164 (Pond E9, 154 ha) and 2628 (Pond E14, 69 ha) echosounder and lidar points within a 0.375-m radius of each other (0.750-m diameter lidar spot size). We found that mean elevations of the lidar points were lower than the echosounder results by 5 ?? 0.1 cm in Pond E9 and 2 ?? 0.2 cm in Pond E14. Only a few points (5% in Pond E9, 2% in Pond E14) differed by more than 20 cm, and some of these values may be explained by residual water in the ponds during the lidar survey or elevation changes that occurred between surveys. Our results suggest that aerial lidar may be a very accurate and rapid way to assess terrain elevations for wetland restoration projects. ?? 2010 Coastal Education and Research Foundation.

  10. Subthreshold micropulse laser reduces anti-VEGF injection burden in patients with diabetic macular edema.

    Science.gov (United States)

    Moisseiev, Elad; Abbassi, Sam; Thinda, Sumeer; Yoon, Joseph; Yiu, Glenn; Morse, Lawrence S

    2018-01-01

    To evaluate the efficacy of micropulse laser in the early treatment of diabetic macular edema (DME) and its associated burden of anti-vascular endothelial growth factor (VEGF) injections. This retrospective comparative study compared a group of 19 eyes with DME treated with micropulse laser to a matched control group of 19 eyes with DME treated with ranibizumab injections without micropulse laser. Recorded parameters included previous medical and ocular history, previous and subsequent ranibizumab injections administered for DME, visual acuity (VA), central macular thickness throughout the follow-up period, and the occurrence of any complications. The improvement in VA was comparable in both groups, at 12 months and at the final follow-up. Patients treated with micropulse laser required significantly fewer ranibizumab injections than their controls, both at 12 months (1.7 ± 2.3 vs 5.6 ± 2.1) and by the end of the follow-up (2.6 ± 3.3 vs 9.3 ± 5.1) (plaser were encountered. Micropulse laser is a safe and effective treatment for DME, which may achieve comparable improvement in VA along with a significant reduction in the burden of anti-VEGF injections. We suggest a treatment approach for its inclusion in the early stages of DME.

  11. Application of Earth Sciencés Technology in Mapping the of Brazilian Coast: Localization, Analysis & Monitoring of the Archaeological Sites with Remote Sensing & LiDAR

    Science.gov (United States)

    Thompson Alves de Souza, Carlos Eduardo

    Application of Earth Sciencés Technology in Mapping the of Brazilian Coast: Localization, Analysis & Monitoring of the Archaeological Sites with Remote Sensing & LiDAR Carlos Eduardo Thompson Alves de Souza cethompsoniii@hotmail.com Archaeologist Member of the European Association of Archaeologists B.A.Archaeology MA.Remote Sensing Abstract The Archaeological Research in Urban Environment with the Air Light Detection and Ranging is problematic for the Overlay Layers mixed with contexts concerning the Interpretation of Archaeological Data. However, in the Underwater Archaeology the results are excellent. This paper considers the application of Remote Sensing and Air Light Detection and Ranging (LIDAR) as separate things as well as Land Archaeology and the Underwater Archaeology. European Archaeologists know very little about Brazil and the article presents an Overview of Research in Brazil with Remote Sensing in Archaeology and Light Detection and Ranging in Land Archaeology and Underwater Archaeology, because Brazil has Continental Dimensions. Braziliańs Methodology for Location, Analysis and Monitoring of Archaeological Sites is necessarily more Complex and Innovative and therefore can serve as a New Paradigm for other archaeologists involved in the Advanced Management Heritage.

  12. Calibration of Ground-based Lidar instrument

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given Ground-based Lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  13. Lidar to lidar calibration of Ground-based Lidar

    DEFF Research Database (Denmark)

    Fernandez Garcia, Sergio; Courtney, Michael

    This report presents the result of the lidar to lidar calibration performed for ground-based lidar. Calibration is here understood as the establishment of a relation between the reference lidar wind speed measurements with measurement uncertainties provided by measurement standard and corresponding...... lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from the reference lidar measurements are given for information only....

  14. Micro-pulses generation in ECR breakdown stimulated by gyrotron radiation at 37,5 GHz

    International Nuclear Information System (INIS)

    Skalyga, V.; Zorin, V.; Izotov, I.; Golubev, S.; Razin, S.; Sidorov, A.; Vodopyanov, A.

    2012-01-01

    The present work is devoted to experimental and theoretical investigation of the creation of short pulsed (< 100 μs) multicharged ion beams. The possibility of quasi-stationary generation of short pulsed beams under conditions of quasi-gasdynamic plasma confinement was shown in recent experiments. Later another way of such beams creation based on the Pre-glow effect was proposed. In present work it was demonstrated that in the case when duration of microwave (MW) pulse is less than formation time of Pre-glow peak, realization of a regime when ion current is negligible during MW pulse and intense multicharged ions flux appears only when MW ends could be possible. Such pulses after the end of MW were called micro-pulses. In the present work the generation of micro-pulses was observed in experiments with ECR discharge stimulated by gyrotron radiation at 37,5 GHz, 100 kW. In this case pulses with duration less than 30 μs were obtained. Probably the same effect was observed in GANIL where 14 GHz radiation was used and pulses with duration about 2 ms were registered. In present work it was shown that the intensity of such micro-pulse could be higher than intensity of Pre-glow peak at the same conditions but with longer MW pulse. The generation of micro-pulses of nitrogen and argon multicharged ions with current of a few mA and length about 30 μs after MW pulse with duration of 30-100 μs was demonstrated. The low level of impurities, high current density and rather high average charge make possible to consider such micro-pulse regime as a possibility for the creation of a short pulsed ion source. The paper is followed by the slides of the presentation. (authors)

  15. Elevation - LiDAR Survey - Roseau County, Minnesota

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — LIDAR Data for Roseau County Minnesota. This project consists of approximately 87 square miles of LIDAR mapping in Roseau County, Minnesota at two sites: area 1,...

  16. Evaluating the potential for site-specific modification of LiDAR DEM derivatives to improve environmental planning-scale wetland identification using Random Forest classification

    Science.gov (United States)

    O'Neil, Gina L.; Goodall, Jonathan L.; Watson, Layne T.

    2018-04-01

    Wetlands are important ecosystems that provide many ecological benefits, and their quality and presence are protected by federal regulations. These regulations require wetland delineations, which can be costly and time-consuming to perform. Computer models can assist in this process, but lack the accuracy necessary for environmental planning-scale wetland identification. In this study, the potential for improvement of wetland identification models through modification of digital elevation model (DEM) derivatives, derived from high-resolution and increasingly available light detection and ranging (LiDAR) data, at a scale necessary for small-scale wetland delineations is evaluated. A novel approach of flow convergence modelling is presented where Topographic Wetness Index (TWI), curvature, and Cartographic Depth-to-Water index (DTW), are modified to better distinguish wetland from upland areas, combined with ancillary soil data, and used in a Random Forest classification. This approach is applied to four study sites in Virginia, implemented as an ArcGIS model. The model resulted in significant improvement in average wetland accuracy compared to the commonly used National Wetland Inventory (84.9% vs. 32.1%), at the expense of a moderately lower average non-wetland accuracy (85.6% vs. 98.0%) and average overall accuracy (85.6% vs. 92.0%). From this, we concluded that modifying TWI, curvature, and DTW provides more robust wetland and non-wetland signatures to the models by improving accuracy rates compared to classifications using the original indices. The resulting ArcGIS model is a general tool able to modify these local LiDAR DEM derivatives based on site characteristics to identify wetlands at a high resolution.

  17. Pain control in orthodontics using a micropulse vibration device: A randomized clinical trial.

    Science.gov (United States)

    Lobre, Wendy D; Callegari, Brent J; Gardner, Gary; Marsh, Curtis M; Bush, Anneke C; Dunn, William J

    2016-07-01

    To investigate the relationship between a micropulse vibration device and pain perception during orthodontic treatment. This study was a parallel group, randomized clinical trial. A total of 58 patients meeting eligibility criteria were assigned using block allocation to one of two groups: an experimental group using the vibration device or a control group (n  =  29 for each group). Patients used the device for 20 minutes daily. Patients rated pain intensity on a visual analog scale at appropriate intervals during the weeks after the separator or archwire appointment. Data were analyzed using repeated measures analysis of variance at α  =  .05. During the 4-month test period, significant differences between the micropulse vibration device group and the control group for overall pain (P  =  .002) and biting pain (P  =  .003) were identified. The authors observed that perceived pain was highest at the beginning of the month, following archwire adjustment. The micropulse vibration device significantly lowered the pain scores for overall pain and biting pain during the 4-month study period.

  18. Lidar to lidar calibration phase 1

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Courtney, Michael

    This report presents a feasibility study of a lidar to lidar (L2L) calibration procedure. Phase one of the project was conducted at Høvsøre, Denmark. Two windcubes were placed next to the 116m met mast and different methods were applied to obtain the sensing height error of the lidars. The purpose...... is to find the most consistent method and use it in a potential lidar to lidar calibration procedure....

  19. Calibration of Ground -based Lidar instrument

    DEFF Research Database (Denmark)

    Villanueva, Héctor; Yordanova, Ginka

    This report presents the result of the lidar calibration performed for the given Ground-based Lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...

  20. The design, development, and test of balloonborne and groundbased lidar systems. Volume 3: Groundbased lidar systems

    Science.gov (United States)

    Shepherd, O.; Aurilio, G.; Bucknam, R. D.; Hurd, A. G.; Robertie, N. F.

    1991-06-01

    This is Volume 3 of a three volume final report on the design, development and test of balloonborne and groundbased lidar systems. Volume 1 describes the design and fabrication of a balloonborne CO2 coherent payload to measure the 10.6 micrometers backscatter from atmospheric aerosols as a function of altitude. Volume 2 describes the August 1987 flight test of Atmospheric Balloonborne Lidar Experiment, ABLE 2. In this volume we describe groundbased lidar development and measurements. A design was developed for installation of the ABLE lidar in the GL rooftop dome. A transportable shed was designed to house the ABLE lidar at the various remote measurement sites. Refurbishment and modification of the ABLE lidar were completed to permit groundbased lidar measurements of clouds and aerosols. Lidar field measurements were made at Ascension Island during SABLE 89. Lidar field measurements were made at Terciera, Azores during GABLE 90. These tasks have been successfully completed, and recommendations for further lidar measurements and data analysis have been made.

  1. Lidar measurements of boundary layer depolarization and CCSEM-EDX compositional analysis of airborne particles on collocated passive samplers throughout the forest canopy during the 2016 airborne pollen season at UMBS, Pellston, MI

    Science.gov (United States)

    Wozniak, M. C.; Steiner, A.; Ault, A. P.; Kort, E. A.; Lersch, T.; Casuccio, G.

    2017-12-01

    Observations of airborne pollen are typically made with volumetric samplers that obtain a time-averaged pollen concentration at a single point. While spatial variations in surface pollen concentrations may be known with these samplers given multiple sampling sites, real-time boundary layer transport of pollen grains cannot be determined except by particle dispersion or tracer transport models. Recently, light detection and ranging (lidar) techniques, such as depolarization, have been used to measure pollen transport and optical properties throughout the boundary layer over time. Here, we use a ground-based micro-pulse lidar (MPL) to observe boundary layer vertical profiles before, during and after the peak anemophilous (wind-driven) pollen season. The lidar depolarization ratio is measured in tandem with the normalized R-squared backscatter (NRB) intensity to determine the contribution of aspherical particles to the scatterers present throughout the boundary layer. Measurements are taken from April 15 - July 12, 2016 at the University of Michigan Biological Station (UMBS) PROPHET outdoor research lab and tower within a largely forested region. UMBS is dominated by Acer rubrum, Betula papyrifera, Pinus resinosa, Quercus rubra and Pinus strobus, all of which began flowering on 4/19, 5/3, 5/25, 5/25 and 6/14, respectively. Temperature, relative humidity and wind speed measured on site determine daytime conditions conducive to pollen dispersion from flowers. Lidar depolarization ratios between 0.08-0.14 and higher are observed in the daytime boundary layer on days shortly after the flowering dates of the aforementioned species, elevated above the background level of 0.06 or less. Lidar observations are supplemented with aerosol compositional analysis determined by computer-controlled scanning electron microscopy and energy-dispersive X-ray spectroscopy (CCSEM-EDX) on passive sampler data from below, within and above the forest canopy at PROPHET tower. Particles are

  2. Tropospheric ozone climatology at two Southern Hemisphere tropical/subtropical sites, (Reunion Island and Irene, South Africa from ozonesondes, LIDAR, and in situ aircraft measurements

    Directory of Open Access Journals (Sweden)

    G. Clain

    2009-03-01

    Full Text Available This paper presents a climatology and trends of tropospheric ozone in the Southwestern Indian Ocean (Reunion Island and South Africa (Irene and Johannesburg. This study is based on a multi-instrumental dataset: PTU-O3 ozonesondes, DIAL LIDAR and MOZAIC airborne instrumentation.

    The seasonal profiles of tropospheric ozone at Reunion Island have been calculated from two different data sets: ozonesondes and LIDAR. The two climatological profiles are similar, except in austral summer when the LIDAR profiles show greater values in the free troposphere, and in the upper troposphere when the LIDAR profiles show lower values during all seasons. These results show that the climatological value of LIDAR profiles must be discussed with care since LIDAR measurements can be performed only under clear sky conditions, and the upper limit of the profile depends on the signal strength.

    In addition, linear trends have been calculated from ozonesonde data at Reunion and Irene. Considering the whole tropospheric column, the trend is slightly positive for Reunion, and more clearly positive for Irene. Trend calculations have also been made separating the troposphere into three layers, and separating the dataset into seasons. Results show that the positive trend for Irene is governed by the lower layer that is affected by industrial pollution and biomass burning. On the contrary, for Reunion Island, the strongest trends are observed in the upper troposphere, and in winter when stratosphere-troposphere exchange is more frequently expected.

  3. IEA Wind Task 32: Wind lidar identifying and mitigating barriers to the adoption of wind lidar

    DEFF Research Database (Denmark)

    Clifton, Andrew; Clive, Peter; Gottschall, Julia

    2018-01-01

    IEA Wind Task 32 exists to identify and mitigate barriers to the adoption of lidar for wind energy applications. It leverages ongoing international research and development activities in academia and industry to investigate site assessment, power performance testing, controls and loads, and complex...... flows. Since its initiation in 2011, Task 32 has been responsible for several recommended practices and expert reports that have contributed to the adoption of ground-based, nacelle-based, and floating lidar by the wind industry. Future challenges include the development of lidar uncertainty models......, best practices for data management, and developing community-based tools for data analysis, planning of lidar measurements and lidar configuration. This paper describes the barriers that Task 32 identified to the deployment of wind lidar in each of these application areas, and the steps that have been...

  4. Initial Observations of Micropulse Elongation of Electron Beams in a SCRF Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A. H. [Fermilab; Thurman-Keup, R. [Fermilab; Edstrom Jr., D. [Fermilab; Ruan, J. [Fermilab; Santucci, J. [Fermilab

    2016-10-09

    Commissioning at the SCRF accelerator at the Fermilab Accelerator Science and Technology (FAST) Facility has included the implementation of a versatile bunch-length monitor located after the 4-dipole chicane bunch compressor for electron beam energies of 20-50 MeV and integrated charges in excess of 10 nC. The team has initially used a Hamamatsu C5680 synchroscan streak camera to assess the effects of space charge on the electron beam bunch lengths. An Al-coated Si screen was used to generate optical transition radiation (OTR) resulting from the beam’s interaction with the screen. The chicane bypass beamline allowed the measurements of the bunch length without the compression stage at the downstream beamline location using OTR and the streak camera. We have observed electron beam bunch lengths from 5 to 16 ps (sigma) for micropulse charges of 60 pC to 800 pC, respectively. We also report a compressed sub-ps micropulse case.

  5. Micropulsed Plasma Thrusters for Attitude Control of a Low-Earth-Orbiting CubeSat

    Science.gov (United States)

    Gatsonis, Nikolaos A.; Lu, Ye; Blandino, John; Demetriou, Michael A.; Paschalidis, Nicholas

    2016-01-01

    This study presents a 3-Unit CubeSat design with commercial-off-the-shelf hardware, Teflon-fueled micropulsed plasma thrusters, and an attitude determination and control approach. The micropulsed plasma thruster is sized by the impulse bit and pulse frequency required for continuous compensation of expected maximum disturbance torques at altitudes between 400 and 1000 km, as well as to perform stabilization of up to 20 deg /s and slew maneuvers of up to 180 deg. The study involves realistic power constraints anticipated on the 3-Unit CubeSat. Attitude estimation is implemented using the q method for static attitude determination of the quaternion using pairs of the spacecraft-sun and magnetic-field vectors. The quaternion estimate and the gyroscope measurements are used with an extended Kalman filter to obtain the attitude estimates. Proportional-derivative control algorithms use the static attitude estimates in order to calculate the torque required to compensate for the disturbance torques and to achieve specified stabilization and slewing maneuvers or combinations. The controller includes a thruster-allocation method, which determines the optimal utilization of the available thrusters and introduces redundancy in case of failure. Simulation results are presented for a 3-Unit CubeSat under detumbling, pointing, and pointing and spinning scenarios, as well as comparisons between the thruster-allocation and the paired-firing methods under thruster failure.

  6. Laser remote sensing of water vapor: Raman lidar development

    International Nuclear Information System (INIS)

    Goldsmith, J.E.M.; Lapp, M.; Bisson, S.E.; Melfi, S.H.; Whiteman, D.N.; Ferrare, R.A.; Evans, K.D.

    1994-01-01

    The goal of this research is the development of a critical design for a Raman lidar system optimized to match ARM Program needs for profiling atmospheric water vapor at CART sites. This work has emphasized the development of enhanced daytime capabilities using Raman lidar techniques. This abstract touches briefly on the main components of the research program, summarizing results of the efforts. A detailed Raman lidar instrument model has been developed to predict the daytime and nighttime performance capabilities of Raman lidar systems. The model simulates key characteristics of the lidar system, using realistic atmospheric profiles, modeled background sky radiance, and lidar system parameters based on current instrument capabilities. The model is used to guide development of lidar systems based on both the solar-blind concept and the narrowband, narrow field-of-view concept for daytime optimization

  7. Micropulse diode laser trabeculoplasty (MDLT: A phase II clinical study with 12 months follow-up

    Directory of Open Access Journals (Sweden)

    Antonio Maria Fea

    2008-06-01

    Full Text Available Antonio Maria Fea, Alex Bosone, Teresa Rolle, Beatrice Brogliatti, Federico Maria GrignoloIstituto di Fisiopatologia Clinica, Clinica Oculistica dell’ Università di Torino, Torino, ItalyObjective: This pilot study evaluates the pressure lowering potential of subthreshold micropulse diode laser trabeculoplasty (MDLT for a clinically meaningful duration in patients with medically uncontrolled open angle glaucoma (OAG.Design: prospective interventional case series.Participants: Thirty-two eyes of 20 consecutive patients with uncontrolled OAG (12 bilateral and 8 unilateral.Methods: Confluent subthreshold laser applications over the inferior 180° of the anterior TM using an 810 nm diode laser in a micropulse operating mode. The intraocular pressure (IOP was measured at baseline and at 1 hour, 1 day, 1 week, 3, 6, 9, and 12 months post-treatment. Flare was measured with a Kowa FM 500 flare-meter at baseline and at 3 hours, 1 day, 1 week, and 12 months post-treatment. After treatment, the patients were maintained on their pre-treatment drug regimen.Main outcome measures: Criteria for treatment response were IOP reduction ≥3 mm Hg and IOP ≤21 mm Hg within the first week after MDLT. Eyes not complying to the above criteria during the follow-up were considered treatment failure. Mean IOP change and percentage of IOP reduction during the follow-up were calculated.Results: One eye was analyzed for bilateral patients. A total of 20 eyes were thus included. Four eyes (20% did not respond to treatment during the first week. One additional eye failed at the 6 month visit. The treatment was successful in 15 eyes (75% at 12 months. The IOP was significantly lower throughout follow-up (p < 0.01. At 12 months, the mean percentage of IOP reduction in the 15 respondent eyes was 22.1% and 12 eyes (60% had IOP reduction higher than 20%. During the first two postoperative days, one eye with pigmentary glaucoma experienced a significant increase of flare

  8. Clear-air lidar dark band

    Science.gov (United States)

    Girolamo, Paolo Di; Scoccione, Andrea; Cacciani, Marco; Summa, Donato; Schween, Jan H.

    2018-04-01

    This paper illustrates measurements carried out by the Raman lidar BASIL in the frame of HOPE, revealing the presence of a clear-air dark band phenomenon (i.e. the appearance of a minimum in lidar backscatter echoes) in the upper portion of the convective boundary layer. The phenomenon is clearly distinguishable in the lidar backscatter echoes at 1064 nm. This phenomenon is attributed to the presence of lignite aerosol particles advected from the surrounding open pit mines in the vicinity of the measuring site.

  9. 2005 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Lewis County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Terrapoint collected Light Detection and Ranging (LiDAR) data for the Lewis County project of 2005. The project site covered approximately 223 square miles, divided...

  10. 2015 OLC Lidar: Chelan

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Quantum Spatial has collected Light Detection and Ranging (LiDAR) data for the Oregon LiDAR Consortium (OLC) Chelan FEMA study area. This study area is located in...

  11. LIDAR Research & Development Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The LIDAR Research and Development labs are used to investigate and improve LIDAR components such as laser sources, optical signal detectors and optical filters. The...

  12. Conically scanning lidar error in complex terrain

    Directory of Open Access Journals (Sweden)

    Ferhat Bingöl

    2009-05-01

    Full Text Available Conically scanning lidars assume the flow to be homogeneous in order to deduce the horizontal wind speed. However, in mountainous or complex terrain this assumption is not valid implying a risk that the lidar will derive an erroneous wind speed. The magnitude of this error is measured by collocating a meteorological mast and a lidar at two Greek sites, one hilly and one mountainous. The maximum error for the sites investigated is of the order of 10 %. In order to predict the error for various wind directions the flows at both sites are simulated with the linearized flow model, WAsP Engineering 2.0. The measurement data are compared with the model predictions with good results for the hilly site, but with less success at the mountainous site. This is a deficiency of the flow model, but the methods presented in this paper can be used with any flow model.

  13. Lidar calibration experiments

    DEFF Research Database (Denmark)

    Ejsing Jørgensen, Hans; Mikkelsen, T.; Streicher, J.

    1997-01-01

    detection to test the reproducibility and uncertainty of lidars. Lidar data were obtained from both single-ended and double-ended Lidar configurations. A backstop was introduced in one of the experiments and a new method was developed where information obtained from the backstop can be used in the inversion...... algorithm. Independent in-situ aerosol plume concentrations were obtained from a simultaneous tracer gas experiment with SF6, and comparisons with the two lidars were made. The study shows that the reproducibility of the lidars is within 15%, including measurements from both sides of a plume...

  14. Complex terrain and wind lidars

    Energy Technology Data Exchange (ETDEWEB)

    Bingoel, F.

    2009-08-15

    This thesis includes the results of a PhD study about complex terrain and wind lidars. The study mostly focuses on hilly and forested areas. Lidars have been used in combination with cups, sonics and vanes, to reach the desired vertical measurement heights. Several experiments are performed in complex terrain sites and the measurements are compared with two different flow models; a linearised flow model LINCOM and specialised forest model SCADIS. In respect to the lidar performance in complex terrain, the results showed that horizontal wind speed errors measured by a conically scanning lidar can be of the order of 3-4% in moderately-complex terrain and up to 10% in complex terrain. The findings were based on experiments involving collocated lidars and meteorological masts, together with flow calculations over the same terrains. The lidar performance was also simulated with the commercial software WAsP Engineering 2.0 and was well predicted except for some sectors where the terrain is particularly steep. Subsequently, two experiments were performed in forested areas; where the measurements are recorded at a location deep-in forest and at the forest edge. Both sites were modelled with flow models and the comparison of the measurement data with the flow model outputs showed that the mean wind speed calculated by LINCOM model was only reliable between 1 and 2 tree height (h) above canopy. The SCADIS model reported better correlation with the measurements in forest up to approx6h. At the forest edge, LINCOM model was used by allocating a slope half-in half out of the forest based on the suggestions of previous studies. The optimum slope angle was reported as 17 deg.. Thus, a suggestion was made to use WAsP Engineering 2.0 for forest edge modelling with known limitations and the applied method. The SCADIS model worked better than the LINCOM model at the forest edge but the model reported closer results to the measurements at upwind than the downwind and this should be

  15. Long-term profiling of mineral dust and pollution aerosol with multiwavelength polarization Raman lidar at the Central Asian site of Dushanbe, Tajikistan: case studies

    Directory of Open Access Journals (Sweden)

    J. Hofer

    2017-12-01

    Full Text Available For the first time, continuous vertically resolved aerosol measurements were performed by lidar in Tajikistan, Central Asia. Observations with the multiwavelength polarization Raman lidar PollyXT were conducted during CADEX (Central Asian Dust EXperiment in Dushanbe, Tajikistan, from March 2015 to August 2016. Co-located with the lidar, a sun photometer was also operated. The goal of CADEX is to provide an unprecedented data set on vertically resolved aerosol optical properties in Central Asia, an area highly affected by climate change but largely missing vertically resolved aerosol measurements. During the 18-month measurement campaign, mineral dust was detected frequently from ground to the cirrus level height. In this study, an overview of the measurement period is given and four typical but different example measurement cases are discussed in detail. Three of them are dust cases and one is a contrasting pollution aerosol case. Vertical profiles of the measured optical properties and the calculated dust and non-dust mass concentrations are presented. Dust source regions were identified by means of backward trajectory analyses. A lofted layer of Middle Eastern dust with an aerosol optical thickness (AOT of 0.4 and an extinction-related Ångström exponent of 0.41 was measured. In comparison, two near-ground dust cases have Central Asian sources. One is an extreme dust event with an AOT of 1.5 and Ångström exponent of 0.12 and the other one is a most extreme dust event with an AOT of above 4 (measured by sun photometer and an Ångström exponent of −0.08. The observed lidar ratios (and particle linear depolarization ratios in the presented dust cases range from 40.3 to 46.9 sr (and 0.18–0.29 at 355 nm and from 35.7 to 42.9 sr (0.31–0.35 at 532 nm wavelength. The particle linear depolarization ratios indicate almost unpolluted dust in the case of a lofted dust layer and pure dust in the near-ground dust cases. The lidar ratio

  16. Temporal characterization of FEL micropulses as function of cavity length detuning using frequency-resolved optical gating

    Energy Technology Data Exchange (ETDEWEB)

    Richman, B.A. [Stanford Univ., CA (United States); DeLong, K.W.; Trebino, R. [Sandia National Lab., Livermore, CA (United States)

    1995-12-31

    Results of frequency resolved optical gating (FROG) measurements on the Stanford mid-IR FEL system show the effect of FEL cavity length detuning on the micropulse temporal structure. The FROG technique enables the acquisition of complete and uniquely invertible amplitude and phase temporal dependence of optical pulses. Unambiguous phase and amplitude profiles are recovered from the data. The optical pulses are nearly transform limited, and the pulse length increases with cavity length detuning.

  17. New Generation Lidar Technology and Applications

    Science.gov (United States)

    Spinhirne, James D.

    1999-01-01

    Lidar has been a tool for atmospheric research for several decades. Until recently routine operational use of lidar was not known. Problems have involved a lack of appropriate technology rather than a lack of applications. Within the last few years, lidar based on a new generation of solid state lasers and detectors have changed the situation. Operational applications for cloud and aerosol research applications are now well established. In these research applications, the direct height profiling capability of lidar is typically an adjunct to other types of sensing, both passive and active. Compact eye safe lidar with the sensitivity for ground based monitoring of all significant cloud and aerosol structure and the reliability to operate full time for several years is now in routine use. The approach is known as micro pulse lidar (MPL). For MPL the laser pulse repetition rate is in the kilohertz range and the pulse energies are in the micro-Joule range. The low pulse energy permits the systems to be eye safe and reliable with solid state lasers. A number of MPL systems have been deployed since 1992 at atmospheric research sites at a variety of global locations. Accurate monitoring of cloud and aerosol vertical distribution is a critical measurement for atmospheric radiation. An airborne application of lidar cloud and aerosol profiling is retrievals of parameters from combined lidar and passive sensing involving visible, infrared and microwave frequencies. A lidar based on a large pulse, solid state diode pumped ND:YAG laser has been deployed on the NASA ER-2 high altitude research aircraft along with multi-spectral visible/IR and microwave imaging radiometers since 1993. The system has shown high reliability in an extensive series of experimental projects for cloud remote sensing. The retrieval of cirrus radiation parameters is an effective application for combined lidar and passive sensing. An approved NASA mission will soon begin long term lidar observation of

  18. The Slope Imaging Multi-Polarization Photon-Counting Lidar: Development and Performance Results

    Science.gov (United States)

    Dabney, Phillip

    2010-01-01

    The Slope Imaging Multi-polarization Photon-counting Lidar is an airborne instrument developed to demonstrate laser altimetry measurement methods that will enable more efficient observations of topography and surface properties from space. The instrument was developed through the NASA Earth Science Technology Office Instrument Incubator Program with a focus on cryosphere remote sensing. The SIMPL transmitter is an 11 KHz, 1064 nm, plane-polarized micropulse laser transmitter that is frequency doubled to 532 nm and split into four push-broom beams. The receiver employs single-photon, polarimetric ranging at 532 and 1064 nm using Single Photon Counting Modules in order to achieve simultaneous sampling of surface elevation, slope, roughness and depolarizing scattering properties, the latter used to differentiate surface types. Data acquired over ice-covered Lake Erie in February, 2009 are documenting SIMPL s measurement performance and capabilities, demonstrating differentiation of open water and several ice cover types. ICESat-2 will employ several of the technologies advanced by SIMPL, including micropulse, single photon ranging in a multi-beam, push-broom configuration operating at 532 nm.

  19. 2015 Lowndes County (GA) Lidar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: NOAA OCM Lidar for Lowndes County, GA with the option to Collect Lidar in Cook and Tift Counties, GA Lidar Data Acquisition and Processing Production Task...

  20. 2015 OLC Lidar: Wasco, WA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — WSI collected Light Detection and Ranging (LiDAR) data for the Oregon LiDAR Consortium (OLC) Wasco County, WA, study area. The Oregon LiDAR Consortium's Wasco County...

  1. A New Framework for Quantifying Lidar Uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Newman, Jennifer, F.; Clifton, Andrew; Bonin, Timothy A.; Churchfield, Matthew J.

    2017-03-24

    As wind turbine sizes increase and wind energy expands to more complex and remote sites, remote sensing devices such as lidars are expected to play a key role in wind resource assessment and power performance testing. The switch to remote sensing devices represents a paradigm shift in the way the wind industry typically obtains and interprets measurement data for wind energy. For example, the measurement techniques and sources of uncertainty for a remote sensing device are vastly different from those associated with a cup anemometer on a meteorological tower. Current IEC standards discuss uncertainty due to mounting, calibration, and classification of the remote sensing device, among other parameters. Values of the uncertainty are typically given as a function of the mean wind speed measured by a reference device. However, real-world experience has shown that lidar performance is highly dependent on atmospheric conditions, such as wind shear, turbulence, and aerosol content. At present, these conditions are not directly incorporated into the estimated uncertainty of a lidar device. In this presentation, we propose the development of a new lidar uncertainty framework that adapts to current flow conditions and more accurately represents the actual uncertainty inherent in lidar measurements under different conditions. In this new framework, sources of uncertainty are identified for estimation of the line-of-sight wind speed and reconstruction of the three-dimensional wind field. These sources are then related to physical processes caused by the atmosphere and lidar operating conditions. The framework is applied to lidar data from an operational wind farm to assess the ability of the framework to predict errors in lidar-measured wind speed.

  2. IEA Wind Task 32: Wind Lidar Identifying and Mitigating Barriers to the Adoption of Wind Lidar

    Directory of Open Access Journals (Sweden)

    Andrew Clifton

    2018-03-01

    Full Text Available IEA Wind Task 32 exists to identify and mitigate barriers to the adoption of lidar for wind energy applications. It leverages ongoing international research and development activities in academia and industry to investigate site assessment, power performance testing, controls and loads, and complex flows. Since its initiation in 2011, Task 32 has been responsible for several recommended practices and expert reports that have contributed to the adoption of ground-based, nacelle-based, and floating lidar by the wind industry. Future challenges include the development of lidar uncertainty models, best practices for data management, and developing community-based tools for data analysis, planning of lidar measurements and lidar configuration. This paper describes the barriers that Task 32 identified to the deployment of wind lidar in each of these application areas, and the steps that have been taken to confirm or mitigate the barriers. Task 32 will continue to be a meeting point for the international wind lidar community until at least 2020 and welcomes old and new participants.

  3. Increase in Central Retinal Edema after Subthreshold Diode Micropulse Laser Treatment of Chronic Central Serous Chorioretinopathy

    Directory of Open Access Journals (Sweden)

    Maciej Gawęcki

    2015-01-01

    Full Text Available Purpose. Subthreshold diode micropulse laser (SDM treatment is believed to be safe method of treating clinical entities involving retinal edema. We present a case of serous edematous reaction of the retina to SDM treatment. Methods. Case report. Results. A patient with chronic central serous chorioretinopathy (CSCR was treated with SDM Yellow multispot laser. Procedure had been preceded by careful titration of the laser power, which after achieving of the threshold parameter was decreased by 50%. The follow-up visit two days after treatment revealed significant central retinal edema and subretinal fluid. Fundus autofluorescence image showed thermal reaction from the RPE in the form of small spots of hyperfluorescence corresponding to the laser multispot pattern used for treatment. Retinal edema resolved after topical bromfenac and single intravitreal bevacizumab injection. Slight pigmentary reaction from the RPE persisted. Conclusion. In the treatment of CSCR, there is a need to significantly reduce threshold SDM power parameters or simply use very low power without titration.

  4. MPL-Net Measurements of Aerosol and Cloud Vertical Distributions at Co-Located AERONET Sites

    Science.gov (United States)

    Welton, Ellsworth J.; Campbell, James R.; Berkoff, Timothy A.; Spinhirne, James D.; Tsay, Si-Chee; Holben, Brent; Starr, David OC. (Technical Monitor)

    2002-01-01

    In the early 1990s, the first small, eye-safe, and autonomous lidar system was developed, the Micropulse Lidar (MPL). The MPL acquires signal profiles of backscattered laser light from aerosols and clouds. The signals are analyzed to yield multiple layer heights, optical depths of each layer, average extinction-to-backscatter ratios for each layer, and profiles of extinction in each layer. In 2000, several MPL sites were organized into a coordinated network, called MPL-Net, by the Cloud and Aerosol Lidar Group at NASA Goddard Space Flight Center (GSFC) using funding provided by the NASA Earth Observing System. tn addition to the funding provided by NASA EOS, the NASA CERES Ground Validation Group supplied four MPL systems to the project, and the NASA TOMS group contributed their MPL for work at GSFC. The Atmospheric Radiation Measurement Program (ARM) also agreed to make their data available to the MPL-Net project for processing. In addition to the initial NASA and ARM operated sites, several other independent research groups have also expressed interest in joining the network using their own instruments. Finally, a limited amount of EOS funding was set aside to participate in various field experiments each year. The NASA Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) project also provides funds to deploy their MPL during ocean research cruises. All together, the MPL-Net project has participated in four major field experiments since 2000. Most MPL-Net sites and field experiment locations are also co-located with sunphotometers in the NASA Aerosol Robotic Network. (AERONET). Therefore, at these locations data is collected on both aerosol and cloud vertical structure as well as column optical depth and sky radiance. Real-time data products are now available from most MPL-Net sites. Our real-time products are generated at times of AERONET aerosol optical depth (AOD) measurements. The AERONET AOD is used as input to our

  5. The design, development, and test of balloonborne and groundbased lidar systems. Volume 1: Balloonborne coherent CO2 lidar system

    Science.gov (United States)

    Shepherd, O.; Aurilio, G.; Bucknam, R. D.; Hurd, A. G.; Rappaport, S. A.

    1991-06-01

    This is Volume 1 of a three volume final report on the design, development, and test of balloonborne and groundbased lidar systems. Volume 2 describes the flight test of Atmospheric Balloonborne Lidar Experiment, ABLE 2, which successfully made atmospheric density backscatter measurements during a flight over White Sands Missile Range. Volume 3 describes groundbased lidar development and measurements, including the design of a telescope dome lidar installation, the design of a transportable lidar shed for remote field sites, and field measurements of atmospheric and cloud backscatter from Ascension Island during SABLE 89 and Terciera, Azores during GABLE 90. In this volume, Volume 1, the design and fabrication of a balloonborne CO2 coherent lidar payload are described. The purpose of this payload is to measure, from altitudes greater than 20 km, the 10.6 micrometers backscatter from atmospheric aerosols as a function of altitude. Minor modifications to the lidar would provide for aerosol velocity measurements to be made. The lidar and payload system design was completed, and major components were fabricated and assembled. These tasks have been successfully completed, and recommendations for further lidar measurements and data analysis have been made.

  6. Observations of Pc5 micropulsation-related electric field oscillations in the equatorial ionosphere

    Directory of Open Access Journals (Sweden)

    C. A. Reddy

    1994-05-01

    Full Text Available A 54.95-MHz coherent backscatter radar, an ionosonde and the magnetometer located at Trivandrum in India (8.5°N, 77°E, 0.5°N dip angle recorded large-amplitude ionospheric fluctuations and magnetic field fluctuations associated with a Pc5 micropulsation event, which occurred during an intense magnetic storm on 24 March 1991 (Ap=161. Simultaneous 100-nT-level fluctuations are also observed in the H-component at Brorfelde, Denmark (55.6°N gm and at Narsarsuaq, Greenland (70.6°N gm. Our study of the above observations shows that the E-W electric field fluctuations in the E- and F-regions and the magnetic field fluctuations at Thumba are dominated by a near-sinusoidal oscillation of 10 min during 1730-1900 IST (1200-1330 UT, the amplitude of the electric field oscillation in the equatorial electrojet (EEJ is 0.1-0.25 mV m-1 and it increases with height, while it is about 1.0 mV m-1 in the F-region, the ground-level H-component oscillation can be accounted for by the ionospheric current oscillation generated by the observed electric field oscillation in the EEJ and the H-component oscillations at Trivandrum and Brorfelde are in phase with each other. The observations are interpreted in terms of a compressional cavity mode resonance in the inner magnetosphere and the associated ionospheric electric field penetrating from high latitudes to the magnetic equator.

  7. Observations of Pc5 micropulsation-related electric field oscillations in equatorial ionosphere

    Science.gov (United States)

    Reddy, C. A.; Ravindran, Sudha; Viswanathan, K. S.; Murthy, B. V. Krishna; Rao, D. R. K.; Araki, T.

    1994-01-01

    A 54.95-MHz coherent backscatter radar, an ionosonde and the magnetometer located at Trivandrum in India (8.5 deg N, 77 deg E, 0.5 deg N dip angle) recorded large-amplitude ionospheric fluctuations and magnetic field fluctuations associated with a Pc5 micropulsation event, which occurred during an intense magnetic storm on 24 March 1991 (A(sub p) = 161). Simultaneous 100-n T-level fluctuations are also observed in the H-component at Brorfelde, Denmark (55.6 deg N gm) and at Narsarsuaq, Greenland (70.6 deg N gm). Our study of the above observations shows that the E-W electric field fluctuations in the E- and F-regions and the magnetic field fluctuations at Thumba are dominated by a near-sinusoidal oscillation of 10 min during 1730-1900 IST (1200-1330 UT), the amplitude of the electric field oscillation in the equatorial electrojet (EEJ) is 0.1-0.25 mV/m and it increases with height, while it is about 1.0 mV/m in the F-region, the ground-level H-component oscillation can be accounted for by the ionospheric current oscillation generated by the observed electric field oscillation in the EEJ and the H-component oscillations at Trivandrum and Brofelde are in phase with each other. The observations are interpreted in terms of a compressional cavity mode resonance in the inner magnetosphere and the assoicated ionospheric electric field penetrating from high latitudes to the magnetic equator.

  8. Observations of Pc5 micropulsation-related electric field oscillations in the equatorial ionosphere

    Directory of Open Access Journals (Sweden)

    C. A. Reddy

    Full Text Available A 54.95-MHz coherent backscatter radar, an ionosonde and the magnetometer located at Trivandrum in India (8.5°N, 77°E, 0.5°N dip angle recorded large-amplitude ionospheric fluctuations and magnetic field fluctuations associated with a Pc5 micropulsation event, which occurred during an intense magnetic storm on 24 March 1991 (Ap=161. Simultaneous 100-nT-level fluctuations are also observed in the H-component at Brorfelde, Denmark (55.6°N gm and at Narsarsuaq, Greenland (70.6°N gm. Our study of the above observations shows that the E-W electric field fluctuations in the E- and F-regions and the magnetic field fluctuations at Thumba are dominated by a near-sinusoidal oscillation of 10 min during 1730-1900 IST (1200-1330 UT, the amplitude of the electric field oscillation in the equatorial electrojet (EEJ is 0.1-0.25 mV m-1 and it increases with height, while it is about 1.0 mV m-1 in the F-region, the ground-level H-component oscillation can be accounted for by the ionospheric current oscillation generated by the observed electric field oscillation in the EEJ and the H-component oscillations at Trivandrum and Brorfelde are in phase with each other. The observations are interpreted in terms of a compressional cavity mode resonance in the inner magnetosphere and the associated ionospheric electric field penetrating from high latitudes to the magnetic equator.

  9. Optimizing Lidar Scanning Strategies for Wind Energy Measurements (Invited)

    Science.gov (United States)

    Newman, J. F.; Bonin, T. A.; Klein, P.; Wharton, S.; Chilson, P. B.

    2013-12-01

    Environmental concerns and rising fossil fuel prices have prompted rapid development in the renewable energy sector. Wind energy, in particular, has become increasingly popular in the United States. However, the intermittency of available wind energy makes it difficult to integrate wind energy into the power grid. Thus, the expansion and successful implementation of wind energy requires accurate wind resource assessments and wind power forecasts. The actual power produced by a turbine is affected by the wind speeds and turbulence levels experienced across the turbine rotor disk. Because of the range of measurement heights required for wind power estimation, remote sensing devices (e.g., lidar) are ideally suited for these purposes. However, the volume averaging inherent in remote sensing technology produces turbulence estimates that are different from those estimated by a sonic anemometer mounted on a standard meteorological tower. In addition, most lidars intended for wind energy purposes utilize a standard Doppler beam-swinging or Velocity-Azimuth Display technique to estimate the three-dimensional wind vector. These scanning strategies are ideal for measuring mean wind speeds but are likely inadequate for measuring turbulence. In order to examine the impact of different lidar scanning strategies on turbulence measurements, a WindCube lidar, a scanning Halo lidar, and a scanning Galion lidar were deployed at the Southern Great Plains Atmospheric Radiation Measurement (ARM) site in Summer 2013. Existing instrumentation at the ARM site, including a 60-m meteorological tower and an additional scanning Halo lidar, were used in conjunction with the deployed lidars to evaluate several user-defined scanning strategies. For part of the experiment, all three scanning lidars were pointed at approximately the same point in space and a tri-Doppler analysis was completed to calculate the three-dimensional wind vector every 1 second. In another part of the experiment, one of

  10. Lidar observations of middle atmospheric gravity wave activity over a low-latitude site (Gadanki, 13.5° N, 79.2° E

    Directory of Open Access Journals (Sweden)

    V. Sivakumar

    2006-05-01

    Full Text Available The low-latitude middle atmospheric gravity wave characteristics are presented using 310 nights of Rayleigh lidar observations made at Gadanki (13.5° N, 79.2° E over the period from March 1998 to December 2002. The gravity wave characteristics are presented in terms of vertical wave number and frequency spectra, along with the estimated potential energy for the four seasons, namely, spring, summer, autumn and winter. The computed wave number spectra for both the stratosphere and the mesosphere are found to differ significantly from a saturated model predicted spectrum. The spectra were found to be shallower at lower wave numbers and steeper at higher wave numbers with transition at ~8.85×10-4 cy/m. The computed frequency spectra seem to follow the model plot with a power law index of -5/3 above a frequency of ~2×10-4 Hz. The estimated potential energy per unit mass increases gradually up to ~60 km and then rather rapidly above this height to reach values of the order of 200J/kg at ~70 km.

  11. High-resolution energetic particle measurements at 6.6 R/sub E/ 1. Electron micropulsations

    International Nuclear Information System (INIS)

    Higbie, P.R.; Belian, R.D.; Baker, D.N.

    1978-01-01

    The three papers dealing with data from satellites 1976--059A which we present in this issue represent the first publication of data from the new series of charged particle analyzer (CPA) instruments designed to measure energetic particle fluxes at geosynchronous altitudes. This first report presents new results on electron micropulsation phenomena and includes a concise description of the instrument. We often observe highly periodic modulations which persist for times as long as 2 hours in the spin-averaged counting rate data. These flux oscillations occur most frequently in the 30- to 300-keV electron data but are occasionally seen in higher-energy electron or low-energy proton data. The pitch angle distributions of the observed modulated fluxes may be either 'cigar-shaped' or 'pancake-shaped.' Oscillations at different energies are in phase, although the gross counting rate may be changing in an energy-time dispersive manner. The occurrence distribution of these modulations in local time suggests that they are related to Pc 5 geomagnetic micropulsations observed at ground stations

  12. 2003 Oahu Coastline Lidar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — LIDAR data is remotely sensed high-resolution elevation data collected by an airborne collection platform. Using a combination of laser rangefinding, GPS positioning...

  13. Alexandrite Lidar Receiver

    National Research Council Canada - National Science Library

    Wilkerson, Thomas

    2000-01-01

    ...". The chosen vendor, Orca Photonics, In. (Redmond, WA), in close collaboration with USU personnel, built a portable, computerized lidar system that not only is suitable as a receiver for a near IR alexandrite laser, but also contains an independent Nd...

  14. LIDAR Thomson scattering

    International Nuclear Information System (INIS)

    1991-07-01

    This collection contains 21 papers on the application and development of LIDAR (Light Detection and Ranging) Thomson scattering techniques for the determination of spatially resolved electron temperature and density in magnetic confinement experiments, particularly tokamaks. Refs, figs and tabs

  15. Lidar 2009 - All Returns

    Data.gov (United States)

    Kansas Data Access and Support Center — LIDAR-derived binary (.las) files containing classified points of all returns. We have 3 classifications Unclassified, Ground, Low points. The average Ground Sample...

  16. Holographic Raman lidar

    International Nuclear Information System (INIS)

    Andersen, G.

    2000-01-01

    Full text: We have constructed a Raman lidar system that incorporates a holographic optical element. By resolving just 3 nitrogen lines in the Resonance Raman spectroscopy (RRS) spectrum, temperature fits as good as 1% at altitudes of 20km can be made in 30 minutes. Due to the narrowband selectivity of the HOE, the lidar provides measurements over a continuous 24hr period. By adding a 4th channel to capture the Rayleigh backscattered light, temperature profiles can be extended to 80km

  17. Installation report - Lidar

    DEFF Research Database (Denmark)

    Georgieva Yankova, Ginka; Villanueva, Héctor

    The report describes the installation, configuration and data transfer for the ground-based lidar. The unit is provided by a customer but is installed and operated by DTU while in this project.......The report describes the installation, configuration and data transfer for the ground-based lidar. The unit is provided by a customer but is installed and operated by DTU while in this project....

  18. Development and Deployment of a Compact Eye-Safe Scanning Differential absorption Lidar (DIAL) for Spatial Mapping of Carbon Dioxide for Monitoring/Verification/Accounting at Geologic Sequestration Sites

    Energy Technology Data Exchange (ETDEWEB)

    Repasky, Kevin

    2014-03-31

    A scanning differential absorption lidar (DIAL) instrument for monitoring carbon dioxide has been developed. The laser transmitter uses two tunable discrete mode laser diodes (DMLD) operating in the continuous wave (cw) mode with one locked to the online absorption wavelength and the other operating at the offline wavelength. Two in-line fiber optic switches are used to switch between online and offline operation. After the fiber optic switch, an acousto- optic modulator (AOM) is used to generate a pulse train used to injection seed an erbium doped fiber amplifier (EDFA) to produce eye-safe laser pulses with maximum pulse energies of 66 {micro}J, a pulse repetition frequency of 15 kHz, and an operating wavelength of 1.571 {micro}m. The DIAL receiver uses a 28 cm diameter Schmidt-Cassegrain telescope to collect that backscattered light, which is then monitored using a photo-multiplier tube (PMT) module operating in the photon counting mode. The DIAL instrument has been operated from a laboratory environment on the campus of Montana State University, at the Zero Emission Research Technology (ZERT) field site located in the agricultural research area on the western end of the Montana State University campus, and at the Big Sky Carbon Sequestration Partnership site located in north-central Montana. DIAL data has been collected and profiles have been validated using a co-located Licor LI-820 Gas Analyzer point sensor.

  19. Development of a Dynamic Lidar Uncertainty Framework

    Energy Technology Data Exchange (ETDEWEB)

    Newman, Jennifer [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Clifton, Andrew [WindForS; Bonin, Timothy [CIRES/NOAA ESRL; Choukulkar, Aditya [CIRES/NOAA ESRL; Brewer, W. Alan [NOAA ESRL; Delgado, Ruben [University of Maryland Baltimore County

    2017-08-07

    As wind turbine sizes increase and wind energy expands to more complex and remote sites, remote-sensing devices such as lidars are expected to play a key role in wind resource assessment and power performance testing. The switch to remote-sensing devices represents a paradigm shift in the way the wind industry typically obtains and interprets measurement data for wind energy. For example, the measurement techniques and sources of uncertainty for a remote-sensing device are vastly different from those associated with a cup anemometer on a meteorological tower. Current IEC standards for quantifying remote sensing device uncertainty for power performance testing consider uncertainty due to mounting, calibration, and classification of the remote sensing device, among other parameters. Values of the uncertainty are typically given as a function of the mean wind speed measured by a reference device and are generally fixed, leading to climatic uncertainty values that apply to the entire measurement campaign. However, real-world experience and a consideration of the fundamentals of the measurement process have shown that lidar performance is highly dependent on atmospheric conditions, such as wind shear, turbulence, and aerosol content. At present, these conditions are not directly incorporated into the estimated uncertainty of a lidar device. In this presentation, we describe the development of a new dynamic lidar uncertainty framework that adapts to current flow conditions and more accurately represents the actual uncertainty inherent in lidar measurements under different conditions. In this new framework, sources of uncertainty are identified for estimation of the line-of-sight wind speed and reconstruction of the three-dimensional wind field. These sources are then related to physical processes caused by the atmosphere and lidar operating conditions. The framework is applied to lidar data from a field measurement site to assess the ability of the framework to predict

  20. LiDAR error estimation with WAsP engineering

    DEFF Research Database (Denmark)

    Bingöl, Ferhat; Mann, Jakob; Foussekis, D.

    2008-01-01

    The LiDAR measurements, vertical wind profile in any height between 10 to 150m, are based on assumption that the measured wind is a product of a homogenous wind. In reality there are many factors affecting the wind on each measurement point which the terrain plays the main role. To model Li......DAR measurements and predict possible error in different wind directions for a certain terrain we have analyzed two experiment data sets from Greece. In both sites LiDAR and met. mast data have been collected and the same conditions are simulated with Riso/DTU software, WAsP Engineering 2.0. Finally measurement...

  1. 2014 OLC Lidar: Colville, WA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — WSI, a Quantum Spatial company, has collected Light Detection and Ranging (LiDAR) data for the Oregon LiDAR Consortium (OLC) Colville study area. This study area is...

  2. 2015 OLC Lidar DEM: Chelan

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Quantum Spatial has collected Light Detection and Ranging (LiDAR) data for the Oregon LiDAR Consortium (OLC) Chelan FEMA study area. This study area is located in...

  3. 2015 OLC Lidar: Okanogan WA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Quantum Spatial has collected Light Detection and Ranging (LiDAR) data for the Oregon LiDAR Consortium (OLC) Okanogan FEMA study area. This study area is located in...

  4. 2012 USGS Lidar: Juneau (AK)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This task order is for planning, acquisition, processing, and derivative products of LiDAR data to be collected for Juneau, Alaska. LiDAR data, and derivative...

  5. The design, development, and test of balloonborne and groundbased lidar systems. Volume 2: Flight test of Atmospheric Balloon Lidar Experiment, ABLE 2

    Science.gov (United States)

    Shepherd, O.; Bucknam, R. D.; Hurd, A. G.; Sheehan, W. H.

    1991-06-01

    This is Volume 3 of a three volume final report on the design, development, and test of balloonborne and groundbased lidar systems. Volume 1 describes the design and fabrication of a balloonborne CO2 coherent payload to measure the 10.6 micrometers backscatter from atmospheric aerosols as a function of altitude. Volume 2 describes the Aug. 1987 flight test of Atmospheric Balloonborne Lidar Experiment, ABLE 2. In this volume we describe groundbased lidar development and measurements. A design was developed for installation of the ABLE lidar in the GL rooftop dome. A transportable shed was designed to house the ABLE lidar at the various remote measurement sites. Refurbishment and modification of the ABLE lidar were completed to permit groundbased lidar measurements of clouds and aerosols. Lidar field measurements were made at Ascension Island during SABLE 89. Lidar field measurements were made at Terciera, Azores during GABLE 90. These tasks were successfully completed, and recommendations for further lidar measurements and data analysis were made.

  6. Detection of Wind Evolution and Lidar Trajectory Optimization for Lidar-Assisted Wind Turbine Control

    Directory of Open Access Journals (Sweden)

    David Schlipf

    2015-11-01

    Full Text Available Recent developments in remote sensing are offering a promising opportunity to rethink conventional control strategies of wind turbines. With technologies such as lidar, the information about the incoming wind field - the main disturbance to the system - can be made available ahead of time. Initial field testing of collective pitch feedforward control shows, that lidar measurements are only beneficial if they are filtered properly to avoid harmful control action. However, commercial lidar systems developed for site assessment are usually unable to provide a usable signal for real time control. Recent research shows, that the correlation between the measurement of rotor effective wind speed and the turbine reaction can be modeled and that the model can be used to optimize a scan pattern. This correlation depends on several criteria such as turbine size, position of the measurements, measurement volume, and how the wind evolves on its way towards the rotor. In this work the longitudinal wind evolution is identified with the line-of-sight measurements of a pulsed lidar system installed on a large commercial wind turbine. This is done by staring directly into the inflowing wind during operation of the turbine and fitting the coherence between the wind at different measurement distances to an exponential model taking into account the yaw misalignment, limitation to line-of-sight measurements and the pulse volume. The identified wind evolution is then used to optimize the scan trajectory of a scanning lidar for lidar-assisted feedforward control in order to get the best correlation possible within the constraints of the system. Further, an adaptive filer is fitted to the modeled correlation to avoid negative impact of feedforward control because of uncorrelated frequencies of the wind measurement. The main results of the presented work are a first estimate of the wind evolution in front of operating wind turbines and an approach which manufacturers of

  7. [Seasonal variations in the myocardial infarction incidence and possible effects of geomagnetic micropulsations on the cardiovascular system in humans].

    Science.gov (United States)

    Kleĭmenova, N G; Kozyreva, O V; Breus, T K; Rapoport, S I

    2007-01-01

    The analysis of the ambulance calls in Moscow, related to myocardial infarction (85.000 events), sudden death (71.700 events), and hypertension crises (165.500 events) over the period of 1979-1981 demonstrated their clear seasonal variations with a profound summer minimum and a winter maximum. The same results were obtained in the analysis of statistical monthly data on sudden death from infarction in Bulgaria over the period of 15 years (1970-1985). However, there are a great number of clinical and statistical studies confirming the rises in the incidence of myocardial infarction, hypertension crise, and sudden death during geomagnetic disturbances, which have maximum occurrence near equinox, not in winter. In order to explain this contradiction, we suggested that one of critical factors that affect the human cardiovascular system is geomagnetic micropulsations Pc1 having the frequency comparable with the frequency of heart rate beatings and winter maximum in their occurrence. The results of a comparative analysis of data of ambulance calls in Moscow related to myocardial infarction and sudden death and the catalog of Pc1 observations at the geophysical observatory "Borok" (Yaroslavl region) are presented. It is shown that in approximately 70% of days with an anomalously large number of ambulance calls related to myocardial infarction, Pc1 micropulsations have been registered. The probability of simultaneous occurrence of myocardial infarction and Pc1 in the winter season was 1.5 times greater than their accidental coincidence. Moreover, it was found that in winter the effects of magnetic storms and Pc1 IM(A) were much higher than in summer. We suggested that one of possible reasons for the seasonal variations in the occurrence of myocardial infarction is an increase in the production of the pineal hormone melatonin in winter which leads to an unstable state of the human organism and an increase in its sensitivity to the effect of geomagnetic pulsations.

  8. Calibration of scanning Lidar

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Courtney, Michael

    This report describes the tests carried out on a scanning lidar at the DTU Test Station for large wind turbines, Høvsøre. The tests were divided in two parts. In the first part, the purpose was to obtain wind speed calibrations at two heights against two cup anemometers mounted on a mast. Additio......This report describes the tests carried out on a scanning lidar at the DTU Test Station for large wind turbines, Høvsøre. The tests were divided in two parts. In the first part, the purpose was to obtain wind speed calibrations at two heights against two cup anemometers mounted on a mast...

  9. Vertical separation of the atmospheric aerosol components by using poliphon retrieval in polarized micro pulse lidar (P-MPL) measurements: case studies of specific climate-relevant aerosol types

    Science.gov (United States)

    Córdoba-Jabonero, Carmen; Sicard, Michaël; Ansmann, Albert; Águila, Ana del; Baars, Holger

    2018-04-01

    POLIPHON (POlarization-LIdar PHOtometer Networking) retrieval consists in the vertical separation of two/three particle components in aerosol mixtures, highlighting their relative contributions in terms of the optical properties and mass concentrations. This method is based on the specific particle linear depolarization ratio given for different types of aerosols, and is applied to the new polarized Micro-Pulse Lidar (P-MPL). Case studies of specific climate-relevant aerosols (dust particles, fire smoke, and pollen aerosols, including a clean case as reference) observed over Barcelona (Spain) are presented in order to evaluate firstly the potential of P-MPLs measurements in combination with POLIPHON for retrieving the vertical separation of those particle components forming aerosol mixtures and their properties.

  10. Evaluating Site-Specific and Generic Spatial Models of Aboveground Forest Biomass Based on Landsat Time-Series and LiDAR Strip Samples in the Eastern USA

    Science.gov (United States)

    Ram Deo; Matthew Russell; Grant Domke; Hans-Erik Andersen; Warren Cohen; Christopher Woodall

    2017-01-01

    Large-area assessment of aboveground tree biomass (AGB) to inform regional or national forest monitoring programs can be efficiently carried out by combining remotely sensed data and field sample measurements through a generic statistical model, in contrast to site-specific models. We integrated forest inventory plot data with spatial predictors from Landsat time-...

  11. An error reduction algorithm to improve lidar turbulence estimates for wind energy

    Directory of Open Access Journals (Sweden)

    J. F. Newman

    2017-02-01

    Full Text Available Remote-sensing devices such as lidars are currently being investigated as alternatives to cup anemometers on meteorological towers for the measurement of wind speed and direction. Although lidars can measure mean wind speeds at heights spanning an entire turbine rotor disk and can be easily moved from one location to another, they measure different values of turbulence than an instrument on a tower. Current methods for improving lidar turbulence estimates include the use of analytical turbulence models and expensive scanning lidars. While these methods provide accurate results in a research setting, they cannot be easily applied to smaller, vertically profiling lidars in locations where high-resolution sonic anemometer data are not available. Thus, there is clearly a need for a turbulence error reduction model that is simpler and more easily applicable to lidars that are used in the wind energy industry. In this work, a new turbulence error reduction algorithm for lidars is described. The Lidar Turbulence Error Reduction Algorithm, L-TERRA, can be applied using only data from a stand-alone vertically profiling lidar and requires minimal training with meteorological tower data. The basis of L-TERRA is a series of physics-based corrections that are applied to the lidar data to mitigate errors from instrument noise, volume averaging, and variance contamination. These corrections are applied in conjunction with a trained machine-learning model to improve turbulence estimates from a vertically profiling WINDCUBE v2 lidar. The lessons learned from creating the L-TERRA model for a WINDCUBE v2 lidar can also be applied to other lidar devices. L-TERRA was tested on data from two sites in the Southern Plains region of the United States. The physics-based corrections in L-TERRA brought regression line slopes much closer to 1 at both sites and significantly reduced the sensitivity of lidar turbulence errors to atmospheric stability. The accuracy of machine

  12. 2004 Alaska Lidar Mapping

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data sets are generated using the OPTECH ALTM 70 kHz LIDAR system mounted onboard AeroMap's twin-engine Cessna 320 aircraft. Classified data sets such as this...

  13. Calibrating nacelle lidars

    Energy Technology Data Exchange (ETDEWEB)

    Courtney, M.

    2013-01-15

    Nacelle mounted, forward looking wind lidars are beginning to be used to provide reference wind speed measurements for the power performance testing of wind turbines. In such applications, a formal calibration procedure with a corresponding uncertainty assessment will be necessary. This report presents four concepts for performing such a nacelle lidar calibration. Of the four methods, two are found to be immediately relevant and are pursued in some detail. The first of these is a line of sight calibration method in which both lines of sight (for a two beam lidar) are individually calibrated by accurately aligning the beam to pass close to a reference wind speed sensor. A testing procedure is presented, reporting requirements outlined and the uncertainty of the method analysed. It is seen that the main limitation of the line of sight calibration method is the time required to obtain a representative distribution of radial wind speeds. An alternative method is to place the nacelle lidar on the ground and incline the beams upwards to bisect a mast equipped with reference instrumentation at a known height and range. This method will be easier and faster to implement and execute but the beam inclination introduces extra uncertainties. A procedure for conducting such a calibration is presented and initial indications of the uncertainties given. A discussion of the merits and weaknesses of the two methods is given together with some proposals for the next important steps to be taken in this work. (Author)

  14. Nacelle lidar power curve

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Wagner, Rozenn

    This report describes the power curve measurements performed with a nacelle LIDAR on a given wind turbine in a wind farm and during a chosen measurement period. The measurements and analysis are carried out in accordance to the guidelines in the procedure “DTU Wind Energy-E-0019” [1]. The reporting...

  15. Lidar 2009 - IMG

    Data.gov (United States)

    Kansas Data Access and Support Center — ESRI Grids 1 meter resolution are created from the ground classified lidar points. The tiles are delivered in 5,000m by 5,000m tiles. The ESRI grids are exported to...

  16. Intercomparison of aerosol measurements performed with multi-wavelength Raman lidars, automatic lidars and ceilometers in the framework of INTERACT-II campaign

    Science.gov (United States)

    Madonna, Fabio; Rosoldi, Marco; Lolli, Simone; Amato, Francesco; Vande Hey, Joshua; Dhillon, Ranvir; Zheng, Yunhui; Brettle, Mike; Pappalardo, Gelsomina

    2018-04-01

    Following the previous efforts of INTERACT (INTERcomparison of Aerosol and Cloud Tracking), the INTERACT-II campaign used multi-wavelength Raman lidar measurements to assess the performance of an automatic compact micro-pulse lidar (MiniMPL) and two ceilometers (CL51 and CS135) in providing reliable information about optical and geometric atmospheric aerosol properties. The campaign took place at the CNR-IMAA Atmospheric Observatory (760 m a. s. l. ; 40.60° N, 15.72° E) in the framework of ACTRIS-2 (Aerosol Clouds Trace gases Research InfraStructure) H2020 project. Co-located simultaneous measurements involving a MiniMPL, two ceilometers and two EARLINET multi-wavelength Raman lidars were performed from July to December 2016. The intercomparison highlighted that the MiniMPL range-corrected signals (RCSs) show, on average, a fractional difference with respect to those of CNR-IMAA Atmospheric Observatory (CIAO) lidars ranging from 5 to 15 % below 2.0 km a.s.l. (above sea level), largely due to the use of an inaccurate overlap correction, and smaller than 5 % in the free troposphere. For the CL51, the attenuated backscatter values have an average fractional difference with respect to CIAO lidars performance is similar to the CL51 below 2.0 km a. s. l. , while in the region above 3 km a. s. l. the differences are about ±40 %. The variability of the CS135 normalization constant is within ±47 %.Finally, additional tests performed during the campaign using the CHM15k ceilometer operated at CIAO showed the clear need to investigate the CHM15k historical dataset (2010-2016) to evaluate potential effects of ceilometer laser fluctuations on calibration stability. The number of laser pulses shows an average variability of 10 % with respect to the nominal power which conforms to the ceilometer specifications. Nevertheless, laser pulses variability follows seasonal behavior with an increase in the number of laser pulses in summer and a decrease in winter. This contributes to

  17. Microperimetry and fundus autofluorescence in diabetic macular edema: subthreshold micropulse diode laser versus modified early treatment diabetic retinopathy study laser photocoagulation.

    Science.gov (United States)

    Vujosevic, Stela; Bottega, Elisa; Casciano, Margherita; Pilotto, Elisabetta; Convento, Enrica; Midena, Edoardo

    2010-06-01

    The purpose of this study was to evaluate and compare microperimetry and fundus autofluorescence (FAF) after subthreshold micropulse diode laser versus modified Early Treatment Diabetic Retinopathy Study photocoagulation for clinically significant diabetic macular edema. A prospective randomized clinical trial including 62 eyes (50 patients) with untreated, center-involving, clinically significant diabetic macular edema was performed. All patients underwent best-corrected visual acuity determination (logarithm of the minimum angle of resolution), slit-lamp biomicroscopy, FAF, optical coherence tomography, microperimetry (macular sensitivity), and fluorescein angiography before and after treatment. Best-corrected visual acuity, optical coherence tomography, microperimetry, and FAF were repeated at 1-, 3-, 6-, 9-, and 12-month follow-up examinations. Fluorescein angiography was performed at baseline and at 6 and 12 months. Before treatment, demographic and macular parameters were not different between the two treatment groups. At 12 months, best-corrected visual acuity remained stable in both groups (P = 0.41 and P = 0.82), mean central retinal thickness decreased in both groups (P = 0.0002 and P autofluorescence never changed in the micropulse diode laser group even after retreatment. In the Early Treatment Diabetic Retinopathy Study group, FAF increased up to 9 months and decreased in 6 eyes (20%) at 12 months. Micropulse diode laser seems to be as effective as modified Early Treatment Diabetic Retinopathy Study laser photocoagulation in the treatment of clinically significant diabetic macular edema. Micropulse diode laser treatment does not determine any change on FAF showing (at least) nonclinically visible damage of the retinal pigment epithelium. Microperimetry data encourage the use of a new, less aggressive laser therapeutic approach in the treatment of clinically significant diabetic macular edema.

  18. 2015 OLC Lidar DEM: Wasco, WA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — WSI collected Light Detection and Ranging (LiDAR) data for the Oregon LiDAR Consortium (OLC) Wasco County, WA, study area. The Oregon LiDAR Consortium's Wasco County...

  19. 2006 MDEQ Camp Shelby, MS Lidar Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This metadata record describes the acquisition and processing of bare earth lidar data, raw point cloud lidar data, lidar intensity data, and floodmap breaklines...

  20. Verifying Operational and Developmental Air Force Weather Cloud Analysis and Forecast Products Using Lidar Data from Department of Energy Atmospheric Radiation Measurement (ARM) Sites

    Science.gov (United States)

    Hildebrand, E. P.

    2017-12-01

    Air Force Weather has developed various cloud analysis and forecast products designed to support global Department of Defense (DoD) missions. A World-Wide Merged Cloud Analysis (WWMCA) and short term Advected Cloud (ADVCLD) forecast is generated hourly using data from 16 geostationary and polar-orbiting satellites. Additionally, WWMCA and Numerical Weather Prediction (NWP) data are used in a statistical long-term (out to five days) cloud forecast model known as the Diagnostic Cloud Forecast (DCF). The WWMCA and ADVCLD are generated on the same polar stereographic 24 km grid for each hemisphere, whereas the DCF is generated on the same grid as its parent NWP model. When verifying the cloud forecast models, the goal is to understand not only the ability to detect cloud, but also the ability to assign it to the correct vertical layer. ADVCLD and DCF forecasts traditionally have been verified using WWMCA data as truth, but this might over-inflate the performance of those models because WWMCA also is a primary input dataset for those models. Because of this, in recent years, a WWMCA Reanalysis product has been developed, but this too is not a fully independent dataset. This year, work has been done to incorporate data from external, independent sources to verify not only the cloud forecast products, but the WWMCA data itself. One such dataset that has been useful for examining the 3-D performance of the cloud analysis and forecast models is Atmospheric Radiation Measurement (ARM) data from various sites around the globe. This presentation will focus on the use of the Department of Energy (DoE) ARM data to verify Air Force Weather cloud analysis and forecast products. Results will be presented to show relative strengths and weaknesses of the analyses and forecasts.

  1. Subthreshold diode-laser micropulse photocoagulation as a primary and secondary line of treatment in management of diabetic macular edema

    Directory of Open Access Journals (Sweden)

    Othman IS

    2014-03-01

    Full Text Available Ihab Saad Othman,1 Sherif Ahmed Eissa,1 Mohamed S Kotb,1 Sherin Hassan Sadek21Cairo University, Cairo, 2Fayoum University, Al Fayoum, EgyptBackground: The purpose of this study was to evaluate subthreshold diode-laser micropulse (SDM photocoagulation as a primary and secondary line of treatment for clinically significant diabetic macular edema (CSDME.Methods: In this prospective nonrandomized case series, 220 cases of nonischemic CSDME were managed primarily and secondarily by SDM photocoagulation on a 15% duty cycle with a mean power of 828 mW and a spot size of 75–125 µm. SDM treatment was repeated at 3–4-month intervals if residual leakage was observed. Additional intravitreal pharmacologic therapy was used according to the response. Follow-up varied from 12 to 19 (mean 14±2.8 months. Novel software designed by the authors was used to record the subvisible threshold laser applications and their parameters on the fundus image of the eye. Evaluation of the results of treatment was done using fluorescein angiography and optical coherence tomography (OCT. Primary outcome measures included changes in visual acuity and foveal thickness at OCT. Secondary outcome measures included visual loss of one or more Snellen lines and laser scars detectable on fundus biomicroscopy or fluorescein angiography.Results: In the primary treatment group, there was significant improvement or stabilization of visual acuity after the first 3–4 months, which was stable thereafter. Visual acuity was stable in the secondary treatment group. A corresponding reduction of macular thickness on OCT was noted during the follow-up period in both groups. Additional therapy included repeat SDM photocoagulation, intravitreal injection of triamcinolone, and pars plana vitrectomy. Laser marks seen as changes in retinal pigment epithelium on fundus biomicroscopy and fluorescein angiography were noted in 3.3% and 5.7% of cases. Our novel software could accurately record the

  2. Lidar: air pollution applications

    International Nuclear Information System (INIS)

    Collis, R.T.H.

    1977-01-01

    This introduction to the use of lidar in air pollution applications is mainly concerned with its capability to detect and monitor atmospheric particulates by elastic backscattering. Even when quite imperceptible to the eye, such particulates may be detected at ranges of several kilometers even by lidars of modest performance. This capability is valuable in connection with air pollution in the following ways: by mapping and tracking inhomogeneities in particulate concentration, atmospheric structure and motion may be monitored; measurements of the optical properties of the atmosphere provide an indication of turbidity or of particulate number or mass concentrations; and the capability of obtaining at a single point return signals from remote atmospheric volumes makes it possible to make range-resolved measurements of gaseous concentration along the path by using the resonant absorption of energy of appropriate wavelengths

  3. Novel Methods for Measuring LiDAR

    Science.gov (United States)

    Ayrey, E.; Hayes, D. J.; Fraver, S.; Weiskittel, A.; Cook, B.; Kershaw, J.

    2017-12-01

    tested against one another using 28 different sites and over 42 different LiDAR acquisitions. The optimal model will then be used to generate regional wall-to-wall forest inventories at a 10 m resolution.

  4. 10-year statistical study of double stratopause structure as observed by lidar over a southern sub-tropical site, Reunion Island (21°S, 55°E)

    CSIR Research Space (South Africa)

    Sivakumar, V

    2006-07-01

    Full Text Available The lidar data collected for about 10 year’s period from 1994 to 2004 are used for the present study. The recorded raw data is in the form of photon count profiles with a height resolution of 300 m and time resolution of 120s. The method of deriving...

  5. 20-year LiDAR observations of stratospheric sudden warming over a mid-latitude site, Observatoire de Haute Provence (44°N, 6°E): Case study and statistical characteristics

    CSIR Research Space (South Africa)

    Charyulu, DV

    2007-11-01

    Full Text Available The present study delineates the characteristics of Stratospheric Sudden Warming (SSW) events observed over the Observatoire de Haute Provence (OHP: 44°N, 6°E). The study uses 20 years of Rayleigh LiDAR temperature measurements for the 1982...

  6. Let’s agree on the casing of Lidar

    Science.gov (United States)

    Deering, Carol; Stoker, Jason M.

    2014-01-01

    Is it lidar, Lidar, LiDAR, LIDAR, LiDar, LiDaR, or liDAR? A comprehensive review of the scientific/technical literature reveals seven different casings of this short form for light detection and ranging. And there could be more.

  7. 2006 Fulton County Georgia Lidar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Light Detection and Ranging (LiDAR) LAS dataset is a survey of Fulton County. The Fulton County LiDAR Survey project area consists of approximately 690.5 square...

  8. Can Wind Lidars Measure Turbulence?

    DEFF Research Database (Denmark)

    Sathe, Ameya; Mann, Jakob; Gottschall, Julia

    2011-01-01

    Modeling of the systematic errors in the second-order moments of wind speeds measured by continuous-wave (ZephIR) and pulsed (WindCube) lidars is presented. These lidars use the conical scanning technique to measure the velocity field. The model captures the effect of volume illumination and coni...

  9. Physical and Optical Characteristics of the October 2010 Haze Event Over Singapore: A Photometric and Lidar Analysis

    Science.gov (United States)

    Salinas, Santo V.; Chew, Boon Ning; Miettinen, Jukka; Campbell, James R.; Welton, Ellsworth J.; Reid, Jeffrey S.; Yu, Liya E.; Liew, Soo Chin

    2013-01-01

    Trans-boundary biomass burning smoke episodes have increased dramatically during the past 20-30 years and have become an annual phenomenon in the South-East-Asia region. On 15th October 2010, elevated levels of fire activity were detected by remote sensing satellites (e.g. MODIS). On the same date, measurements of fine particulate matter (PM2.5) at Singapore and Malaysia found high levels of fine mode particles in the local environment. All these observations were indicative of the initial onset of a smoke episode that lasted for several days. In this work, we investigate the temporal evolution of this smoke episode by analyzing the physical and optical properties of smoke particles with the aid of an AERONET Sun photometer, an MPLNet micropulse lidar, and surface PM2.5 measurements. Elevated levels of fire activity coupled with high aerosol optical depth and PM2.5 were observed over a period of nine days. Increased variability of parameters such as aerosol optical depth, Angstrom exponent number and its fine mode equivalents all indicated high levels of fine particulate presence in the atmosphere. Smoke particle growth due to aging, coagulation and condensation mechanisms was detected during the afternoons and over several days. Retrieved lidar ratios were compatible with the presence of fine particulate within the boundary/aerosol layer. Moreover, retrieved particle size distribution as well as single scattering albedo indicated the prevalence of the fine mode particulate regime as well as particles showing enhanced levels of absorption respectively.

  10. 2017 NOAA/OCM Unmanned Aerial System Lidar: Grand Bay NERR

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Quantum Spatial (QSI) and PrecisionHawk (PH) collected lidar for test sites within the Grand Bay National Estuarine Research Reserve (NERR) using an unmanned aerial...

  11. 2017 NOAA/OCM Unmanned Aerial System Lidar DEM: Grand Bay NERR

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Quantum Spatial (QSI) and PrecisionHawk (PH) collected lidar for test sites within the Grand Bay National Estuarine Research Reserve (NERR) using an unmanned aerial...

  12. LIDAR COMBINED SCANNING UNIT

    Directory of Open Access Journals (Sweden)

    V. V. Elizarov

    2016-11-01

    Full Text Available Subject of Research. The results of lidar combined scanning unit development for locating leaks of hydrocarbons are presented The unit enables to perform high-speed scanning of the investigated space in wide and narrow angle fields. Method. Scanning in a wide angular field is produced by one-line scanning path by means of the movable aluminum mirror with a frequency of 20Hz and amplitude of 20 degrees of swing. Narrowband scanning is performed along a spiral path by the deflector. The deflection of the beam is done by rotation of the optical wedges forming part of the deflector at an angle of ±50. The control function of the scanning node is performed by a specialized software product written in C# programming language. Main Results. This scanning unit allows scanning the investigated area at a distance of 50-100 m with spatial resolution at the level of 3 cm. The positioning accuracy of the laser beam in space is 15'. The developed scanning unit gives the possibility to browse the entire investigated area for the time not more than 1 ms at a rotation frequency of each wedge from 50 to 200 Hz. The problem of unambiguous definition of the beam geographical coordinates in space is solved at the software level according to the rotation angles of the mirrors and optical wedges. Lidar system coordinates are determined by means of GPS. Practical Relevance. Development results open the possibility for increasing the spatial resolution of scanning systems of a wide range of lidars and can provide high positioning accuracy of the laser beam in space.

  13. Making lidar more photogenic: creating band combinations from lidar information

    Science.gov (United States)

    Stoker, Jason M.

    2010-01-01

    Over the past five to ten years the use and applicability of light detection and ranging (lidar) technology has increased dramatically. As a result, an almost exponential amount of lidar data is being collected across the country for a wide range of applications, and it is currently the technology of choice for high resolution terrain model creation, 3-dimensional city and infrastructure modeling, forestry and a wide range of scientific applications (Lin and Mills, 2010). The amount of data that is being delivered across the country is impressive. For example, the U.S. Geological Survey’s (USGS) Center for Lidar Information Coordination and Knowledge (CLICK), which is a National repository of USGS and partner lidar point cloud datasets (Stoker et al., 2006), currently has 3.5 percent of the United States covered by lidar, and has approximately another 5 percent in the processing queue. The majority of data being collected by the commercial sector are from discrete-return systems, which collect billions of lidar points in an average project. There are also a lot of discussions involving a potential National-scale Lidar effort (Stoker et al., 2008).

  14. Balloonborne lidar experiment

    Science.gov (United States)

    Shepherd, O.; Aurilio, G.; Bucknam, R. D.; Brooke, R. W.; Hurd, A. G.

    1980-12-01

    The object of this contract was to design a balloonborne lidar experiment capable of performing nightime atmospheric density measurements in the 10 to 40 km altitude domain with a resolution of 100 meters. The payload includes a frequency-tripled Nd:YAG laser with outputs at 353 and 1064 nm, a telescoped receiver with PMT detectors, a command-controlled optical pointing system, and support systems, including thermal control, telemetry, command, and power. Density measurements would be made using the back-scattered 353 nm radiation data with aerosol corrections obtained from 1064 nm radiation scatterings.

  15. Compressive full waveform lidar

    Science.gov (United States)

    Yang, Weiyi; Ke, Jun

    2017-05-01

    To avoid high bandwidth detector, fast speed A/D converter, and large size memory disk, a compressive full waveform LIDAR system, which uses a temporally modulated laser instead of a pulsed laser, is studied in this paper. Full waveform data from NEON (National Ecological Observatory Network) are used. Random binary patterns are used to modulate the source. To achieve 0.15 m ranging resolution, a 100 MSPS A/D converter is assumed to make measurements. SPIRAL algorithm with canonical basis is employed when Poisson noise is considered in the low illuminated condition.

  16. In-situ Calibration of Ground -based Lidar instrument

    DEFF Research Database (Denmark)

    Georgieva Yankova, Ginka; Villanueva, Héctor

    This report presents the result of the lidar in-situ calibration performed at DTU’s test site for large wind turbine at Østerild, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertainties provided by mea...

  17. RIVM Tropospheric ozone LIDAR Measurements during TROLIX'91

    NARCIS (Netherlands)

    Apituley A

    1991-01-01

    For the intercomparison of several LIDAR systems for the vertical profiling of tropospheric ozone developed in the EUREKA/EUROTRAC subproject TESLAS a field campaign was held at the RIVM site in Bilthoven, the Netherlands, during the period from June 10 to June 28, 1991. In this report an overview

  18. Lidar detection of carbon dioxide in volcanic plumes

    Science.gov (United States)

    Fiorani, Luca; Santoro, Simone; Parracino, Stefano; Maio, Giovanni; Del Franco, Mario; Aiuppa, Alessandro

    2015-06-01

    Volcanic gases give information on magmatic processes. In particular, anomalous releases of carbon dioxide precede volcanic eruptions. Up to now, this gas has been measured in volcanic plumes with conventional measurements that imply the severe risks of local sampling and can last many hours. For these reasons and for the great advantages of laser sensing, the thorough development of volcanic lidar has been undertaken at the Diagnostics and Metrology Laboratory (UTAPRAD-DIM) of the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA). In fact, lidar profiling allows one to scan remotely volcanic plumes in a fast and continuous way, and with high spatial and temporal resolution. Two differential absorption lidar instruments will be presented in this paper: BILLI (BrIdge voLcanic LIdar), based on injection seeded Nd:YAG laser, double grating dye laser, difference frequency mixing (DFM) and optical parametric amplifier (OPA), and VULLI (VULcamed Lidar), based on injection seeded Nd:YAG laser and optical parametric oscillator (OPO). The first one is funded by the ERC (European Research Council) project BRIDGE and the second one by the ERDF (European Regional Development Fund) project VULCAMED. While VULLI has not yet been tested in a volcanic site, BILLI scanned the gas emitted by Pozzuoli Solfatara (Campi Flegrei volcanic area, Naples, Italy) during a field campaign carried out from 13 to 17 October 2014. Carbon dioxide concentration maps were retrieved remotely in few minutes in the crater area. Lidar measurements were in good agreement with well-established techniques, based on different operating principles. To our knowledge, it is the first time that carbon dioxide in a volcanic plume is retrieved by lidar, representing the first direct measurement of this kind ever performed on an active volcano and showing the high potential of laser remote sensing in geophysical research.

  19. First measurements of electron-beam transit times and micropulse elongation in a photoelectric injector at the High-Brightness Accelerator FEL (HIBAF)

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A.H.; Carlsten, B.E.; Feldman, R.B.

    1990-01-01

    Key aspects of the dynamics of a photoelectric injector (PEI) on the Los Alamos High-Brightness Accelerator FEL (HIBAF) facility have been investigated using a synchroscan streak camera. By phase-locking the streak camera sweep to the reference 108.3 MHz rf signal, the variations of micropulse temporal elongations (30 to 80% over the drive-laser pulse length) and of transit times (25 ps for a 16{degree}-phase change) were observed for the first time. These results were in good agreement with PARMELA simulations. 2 refs., 8 figs.

  20. Raman lidar water vapor profiling over Warsaw, Poland

    Science.gov (United States)

    Stachlewska, Iwona S.; Costa-Surós, Montserrat; Althausen, Dietrich

    2017-09-01

    Water vapor mixing ratio and relative humidity profiles were derived from the multi-wavelength Raman PollyXT lidar at the EARLINET site in Warsaw, using the Rayleigh molecular extinction calculation based on atmospheric temperature and pressure from three different sources: i) the standard atmosphere US 62, ii) the Global Data Assimilation System (GDAS) model output, and iii) the WMO 12374 radiosoundings launched at Legionowo. With each method, 136 midnight relative humidity profiles were obtained for lidar observations from July 2013 to August 2015. Comparisons of these profiles showed in favor of the latter method (iii), but it also indicated that the other two data sources could replace it, if necessary. Such use was demonstrated for an automated retrieval of water vapor mixing ratio from dusk until dawn on 19/20 March 2015; a case study related to an advection of biomass burning aerosol from forest fires over Ukraine. Additionally, an algorithm that applies thresholds to the radiosounding relative humidity profiles to estimate macro-physical cloud vertical structure was used for the first time on the Raman lidar relative humidity profiles. The results, based on a subset of 66 profiles, indicate that below 6 km cloud bases/tops can be successfully obtained in 53% and 76% cases from lidar and radiosounding profiles, respectively. Finally, a contribution of the lidar derived mean relative humidity to cloudy conditions within the range of 0.8 to 6.2 km, in comparison to clear-sky conditions, was estimated.

  1. Waveform LiDAR across forest biomass gradients

    Science.gov (United States)

    Montesano, P. M.; Nelson, R. F.; Dubayah, R.; Sun, G.; Ranson, J.

    2011-12-01

    Detailed information on the quantity and distribution of aboveground biomass (AGB) is needed to understand how it varies across space and changes over time. Waveform LiDAR data is routinely used to derive the heights of scattering elements in each illuminated footprint, and the vertical structure of vegetation is related to AGB. Changes in LiDAR waveforms across vegetation structure gradients can demonstrate instrument sensitivity to land cover transitions. A close examination of LiDAR waveforms in footprints across a forest gradient can provide new insight into the relationship of vegetation structure and forest AGB. In this study we use field measurements of individual trees within Laser Vegetation Imaging Sensor (LVIS) footprints along transects crossing forest to non-forest gradients to examine changes in LVIS waveform characteristics at sites with low (field AGB measurements to original and adjusted LVIS waveforms to detect the forest AGB interval along a forest - non-forest transition in which the LVIS waveform lose the ability to discern differences in AGB. Our results help identify the lower end the forest biomass range that a ~20m footprint waveform LiDAR can detect, which can help infer accumulation of biomass after disturbances and during forest expansion, and which can guide the use of LiDAR within a multi-sensor fusion biomass mapping approach.

  2. Statistical-uncertainty-based adaptive filtering of lidar signals

    International Nuclear Information System (INIS)

    Fuehrer, P. L.; Friehe, C. A.; Hristov, T. S.; Cooper, D. I.; Eichinger, W. E.

    2000-01-01

    An adaptive filter signal processing technique is developed to overcome the problem of Raman lidar water-vapor mixing ratio (the ratio of the water-vapor density to the dry-air density) with a highly variable statistical uncertainty that increases with decreasing photomultiplier-tube signal strength and masks the true desired water-vapor structure. The technique, applied to horizontal scans, assumes only statistical horizontal homogeneity. The result is a variable spatial resolution water-vapor signal with a constant variance out to a range limit set by a specified signal-to-noise ratio. The technique was applied to Raman water-vapor lidar data obtained at a coastal pier site together with in situ instruments located 320 m from the lidar. The micrometerological humidity data were used to calibrate the ratio of the lidar gains of the H 2 O and the N 2 photomultiplier tubes and set the water-vapor mixing ratio variance for the adaptive filter. For the coastal experiment the effective limit of the lidar range was found to be approximately 200 m for a maximum noise-to-signal variance ratio of 0.1 with the implemented data-reduction procedure. The technique can be adapted to off-horizontal scans with a small reduction in the constraints and is also applicable to other remote-sensing devices that exhibit the same inherent range-dependent signal-to-noise ratio problem. (c) 2000 Optical Society of America

  3. 2012 Oregon Lidar Consortium (OLC) Lidar DEM: Keno (OR)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. (WSI) collected Light Detection and Ranging (LiDAR) data of the Oregon Keno Study Area for the Oregon Department of Geology and Mineral...

  4. 2012 Oregon Lidar Consortium (OLC) Lidar: Keno (OR)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. (WSI) collected Light Detection and Ranging (LiDAR) data of the Oregon Keno Study Area for the Oregon Department of Geology and Mineral...

  5. Characterizing the Vertical Distribution of Aerosols using Ground-based Multiwavelength Lidar Data

    Science.gov (United States)

    Ferrare, R. A.; Thorsen, T. J.; Clayton, M.; Mueller, D.; Chemyakin, E.; Burton, S. P.; Goldsmith, J.; Holz, R.; Kuehn, R.; Eloranta, E. W.; Marais, W.; Newsom, R. K.; Liu, X.; Sawamura, P.; Holben, B. N.; Hostetler, C. A.

    2016-12-01

    Observations of aerosol optical and microphysical properties are critical for developing and evaluating aerosol transport model parameterizations and assessing global aerosol-radiation impacts on climate. During the Combined HSRL And Raman lidar Measurement Study (CHARMS), we investigated the synergistic use of ground-based Raman lidar and High Spectral Resolution Lidar (HSRL) measurements to retrieve aerosol properties aloft. Continuous (24/7) operation of these co-located lidars during the ten-week CHARMS mission (mid-July through September 2015) allowed the acquisition of a unique, multiwavelength ground-based lidar dataset for studying aerosol properties above the Southern Great Plains (SGP) site. The ARM Raman lidar measured profiles of aerosol backscatter, extinction and depolarization at 355 nm as well as profiles of water vapor mixing ratio and temperature. The University of Wisconsin HSRL simultaneously measured profiles of aerosol backscatter, extinction and depolarization at 532 nm and aerosol backscatter at 1064 nm. Recent advances in both lidar retrieval theory and algorithm development demonstrate that vertically-resolved retrievals using such multiwavelength lidar measurements of aerosol backscatter and extinction can help constrain both the aerosol optical (e.g. complex refractive index, scattering, etc.) and microphysical properties (e.g. effective radius, concentrations) as well as provide qualitative aerosol classification. Based on this work, the NASA Langley Research Center (LaRC) HSRL group developed automated algorithms for classifying and retrieving aerosol optical and microphysical properties, demonstrated these retrievals using data from the unique NASA/LaRC airborne multiwavelength HSRL-2 system, and validated the results using coincident airborne in situ data. We apply these algorithms to the CHARMS multiwavelength (Raman+HSRL) lidar dataset to retrieve aerosol properties above the SGP site. We present some profiles of aerosol effective

  6. 2009 SCDRN Lidar: Florence County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The South Carolina Department of Natural Resources (SCDNR) contracted with Sanborn to provide LiDAR mapping services for Florence County, SC. Utilizing multi-return...

  7. 2006 FEMA Lidar: Hawaiian Islands

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The FEMA Task Order 26 LiDAR data set was collected by Airborne 1 Corporation of El Segundo, California in September - December of 2006 for URS Corp.

  8. 2009 SCDNR Charleston County Lidar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Photoscience completed the original collection and classification of the multiple return LiDAR of Charleston County, South Carolina in the winter of 2006-2007. In...

  9. 2009 Chatham County Georgia Lidar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — LiDAR generated point cloud acquired in spring 2009 for Chatham County, Georgia for the Metropolitan Planning Commission. The data are classified as follows: Class 1...

  10. 2014 NJMC Lidar: Hackensack Meadowlands

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In February 2014, Quantum Spatial, Inc. (QSI) was contracted by the New Jersey Meadowlands Commission (NJMC) to collect Light Detection and Ranging (LiDAR) data in...

  11. Alabama 2003 Lidar Coverage, USACE

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — The Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) has performed a coastal survey along the Gulf of Mexico in the summer of 2003. The data...

  12. 2014 Mobile County, AL Lidar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Atlantic was contracted to acquire high resolution topographic LiDAR (Light Detection and Ranging) data located in Mobile County, Alabama. The intent was to collect...

  13. 2008 City of Baltimore Lidar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In the spring of 2008, the City of Baltimore expressed an interest to upgrade the City GIS Database with mapping quality airborne LiDAR data. The City of Baltimore...

  14. 2013 USGS Lidar: Norfolk (VA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Laser Mapping Specialist, Inc (LMSI) and The Atlantic Group (Atlantic) provided high accuracy, calibrated multiple return LiDAR for roughly 1,130 square miles around...

  15. 2009 SCDNR Horry County Lidar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sanborn Map Company completed the original classification of the multiple return LiDAR of Horry County, South Carolina in 2009. In 2013, Dewberry was tasked with...

  16. LIDAR and atmosphere remote sensing

    CSIR Research Space (South Africa)

    Venkataraman, S

    2008-05-01

    Full Text Available using state of the art Light Detection And Ranging (LiDAR) instrumentation and other active and passive remote sensing tools. First “Lidar Field Campaign” • 2-day measurement campaign at University of Pretoria • First 23-hour continuous measurement... head2rightCirrus cloud morphology and dynamics. Atmospheric Research in Southern Africa and Indian Ocean (ARSAIO) Slide 24 © CSIR 2008 www.csir.co.za Middle atmosphere dynamics and thermal structure: comparative studies from...

  17. Balloonborne lidar payloads for remote sensing

    Science.gov (United States)

    Shepherd, O.; Aurilio, G.; Hurd, A. G.; Rappaport, S. A.; Reidy, W. P.; Rieder, R. J.; Bedo, D. E.; Swirbalus, R. A.

    1994-02-01

    A series of lidar experiments has been conducted using the Atmospheric Balloonborne Lidar Experiment payload (ABLE). These experiments included the measurement of atmospheric Rayleigh and Mie backscatter from near space (approximately 30 km) and Raman backscatter measurements of atmospheric constituents as a function of altitude. The ABLE payload consisted of a frequency-tripled Nd:YAG laser transmitter, a 50 cm receiver telescope, and filtered photodetectors in various focal plane configurations. The payload for lidar pointing, thermal control, data handling, and remote control of the lidar system. Comparison of ABLE performance with that of a space lidar shows significant performance advantages and cost effectiveness for balloonborne lidar systems.

  18. Statistical correction of lidar-derived digital elevation models with multispectral airborne imagery in tidal marshes

    Science.gov (United States)

    Buffington, Kevin J.; Dugger, Bruce D.; Thorne, Karen M.; Takekawa, John Y.

    2016-01-01

    Airborne light detection and ranging (lidar) is a valuable tool for collecting large amounts of elevation data across large areas; however, the limited ability to penetrate dense vegetation with lidar hinders its usefulness for measuring tidal marsh platforms. Methods to correct lidar elevation data are available, but a reliable method that requires limited field work and maintains spatial resolution is lacking. We present a novel method, the Lidar Elevation Adjustment with NDVI (LEAN), to correct lidar digital elevation models (DEMs) with vegetation indices from readily available multispectral airborne imagery (NAIP) and RTK-GPS surveys. Using 17 study sites along the Pacific coast of the U.S., we achieved an average root mean squared error (RMSE) of 0.072 m, with a 40–75% improvement in accuracy from the lidar bare earth DEM. Results from our method compared favorably with results from three other methods (minimum-bin gridding, mean error correction, and vegetation correction factors), and a power analysis applying our extensive RTK-GPS dataset showed that on average 118 points were necessary to calibrate a site-specific correction model for tidal marshes along the Pacific coast. By using available imagery and with minimal field surveys, we showed that lidar-derived DEMs can be adjusted for greater accuracy while maintaining high (1 m) resolution.

  19. Lidar-based Research and Innovation at DTU Wind Energy - a Review

    Science.gov (United States)

    Mikkelsen, T.

    2014-06-01

    As wind turbines during the past decade have increased in size so have the challenges met by the atmospheric boundary-layer meteorologists and the wind energy society to measure and characterize the huge-volume wind fields surpassing and driving them. At the DTU Wind Energy test site "Østerild" for huge wind turbines, the hub-height of a recently installed 8 MW Vestas V164 turbine soars 143 meters up above the ground, and its rotor of amazing 164 meters in diameter make the turbine tips flicker 225 meters into the sky. Following the revolution in photonics-based telecommunication at the turn of the Millennium new fibre-based wind lidar technologies emerged and DTU Wind Energy, at that time embedded within Rise National Laboratory, began in collaboration with researchers from wind lidar companies to measure remote sensed wind profiles and turbulence structures within the atmospheric boundary layer with the emerging, at that time new, all-fibre-based 1.55 μ coherent detection wind lidars. Today, ten years later, DTU Wind Energy routinely deploys ground-based vertical profilers instead of met masts for high-precision measurements of mean wind profiles and turbulence profiles. At the departments test site "Høvsøre" DTU Wind Energy also routinely calibrate and accredit wind lidar manufactures wind lidars. Meanwhile however, new methodologies for power curve assessment based on ground-based and nacelle based lidars have also emerged. For improving the turbines power curve assessments and for advancing their control with feed-forward wind measurements experience has also been gained with wind lidars installed on turbine nacelles and integrated into the turbines rotating spinners. A new mobile research infrastructure WindScanner.dk has also emerged at DTU Wind Energy. Wind and turbulence fields are today scanned from sets of three simultaneously in space and time synchronized scanning lidars. One set consists of three fast scanning continuous-wave based wind lidars

  20. Enlarged pores treated with a combination of Q-switched and micropulsed 1064 nm Nd:YAG laser with and without topical carbon suspension: A simultaneous split-face trial

    OpenAIRE

    Chung, HJ; Goo, BC; Lee, HJ; Roh, MR; Chung, KY

    2011-01-01

    Background and aims: Enlarged facial pores remain one of the major cosmetic concerns among Asian females. This study attempted to assess and compare the efficacy of a combination of the Q-switched and quasi long-pulsed (micropulsed) Nd:YAG laser to reduce the size of the enlarged pores with and without an exogenous photoenhancer.

  1. Cirrus and aerosol lidar profilometer - analysis and results

    Energy Technology Data Exchange (ETDEWEB)

    Spinhirne, J.D.; Scott, V.S. [NASA Goddard Space Flight Center, Greenbelt, MD (United States); Reagan, J.A.; Galbraith, A. [Univ. of Arizona, Tucson, AZ (United States)

    1996-04-01

    A cloud and aerosol lidar set from over a year of near continuous operation of a micro pulse lidar (MPL) instrument at the Cloud and Radiation Testbed (CART) site has been established. MPL instruments are to be included in the Ames Research Center (ARC) instrument compliments for the SW Pacific and Arctic ARM sites. Operational processing algorithms are in development for the data sets. The derived products are to be cloud presence and classification, base height, cirrus thickness, cirrus optical thickness, cirrus extinction profile, aerosol optical thickness and profile, and planetary boundary layer (PBL) height. A cloud presence and base height algorithm is in use, and a data set from the CART site is available. The scientific basis for the algorithm development of the higher level data products and plans for implementation are discussed.

  2. 2015 OLC Lidar DEM: Big Wood, ID

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Quantum Spatial has collected Light Detection and Ranging (LiDAR) data for the Oregon LiDAR Consortium (OLC) Big Wood 2015 study area. This study area is located in...

  3. Iowa LiDAR Mapping Project

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — This is collection level metadata for LAS and ASCII data files from the statewide Iowa Lidar Project. The Iowa Light Detection and Ranging (LiDAR) Project collects...

  4. 2007 South Carolina DNR Lidar: Dorchester County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Woolpert Inc. conducted a LiDAR survey to acquire LiDAR capable of producing a DEM for orthophoto rectification and able to support 2-foot contour specifications....

  5. 2015 OLC FEMA Lidar: Snake River, ID

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Quantum Spatial has collected Light Detection and Ranging (LiDAR) data for the Oregon LiDAR Consortium (OLC) Snake River FEMA study area. This study area is located...

  6. 2007 South Carolina DNR Lidar: Anderson County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The LiDAR data acquisition was executed in 5 sessions, from March 7 to March 9, 2007. The airborne GPS (ABGPS) base stations supporting the LiDAR acquisition...

  7. 2011 South Carolina DNR Lidar: York County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Towill Inc. collected LiDAR for over 3,500 square miles in York, Pickens, Anderson, and Oconee Counties in South Carolina. This metadata covers the LiDAR produced...

  8. 2014 PSLC Lidar: City of Redmond

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In February 2014, Quantum Spatial (QSI) was contracted by the Puget Sound LiDAR Consortium (PSLC) to collect Light Detection and Ranging (LiDAR) data for the City of...

  9. 2008 St. Johns County, FL Countywide Lidar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne terrestrial LiDAR was collected for St. Johns County, FL. System Parameters/Flight Plan. The LiDAR system acquisition parameters were developed based on a...

  10. 2006 Volusia County Florida LiDAR

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is the lidar data for Volusia County, Florida, approximately 1,432 square miles, acquired in early March of 2006. A total of 143 flight lines of Lidar...

  11. 2009 Bayfield County Lake Superior Lidar Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The LIDAR survey presents digital elevation data sets of a bald earth surface model and 2ft interval contours covering Bayfield County, Wisconsin. The LIDAR data was...

  12. 2014 OLC Lidar DEM: Colville, WA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — WSI, a Quantum Spatial company, has collected Light Detection and Ranging (LiDAR) data for the Oregon LiDAR Consortium (OLC) Colville study area. This study area is...

  13. 2014 Horry County, South Carolina Lidar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is comprised of lidar point cloud data. This project required lidar data to be acquired over Horry County, South Carolina. The total area of the Horry...

  14. 2010 ARRA Lidar: 4 Southeast Counties (MI)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: Southeast Michigan LiDAR LiDAR Data Acquisition and Processing Production Task- Monroe, St. Clair, Macomb, and Livingston Counties SEMCOG CONTRACT:...

  15. 2015 Oregon Department Forestry Lidar: Northwest OR

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — GeoTerra, Inc. was selected by Oregon Department of Forestry to provide Lidar remote sensing data including LAZ files of the classified Lidar points and surface...

  16. 2007 USGS Lidar: Canyon Fire (CA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This Southern California Light Detection and Ranging (LiDAR) data is to provide high accuracy LIDAR data. These datasets will be the initial acquisition to support...

  17. Remote sensing of methane emissions by combining optical similitude absorption spectroscopy (OSAS and lidar

    Directory of Open Access Journals (Sweden)

    Galtier Sandrine

    2018-01-01

    Full Text Available Monitoring the emission of gases is difficult to achieve in industrial sites and in environments presenting poor infrastructures. Hence, robust methodologies should be developed and coupled to Lidar technology to allow remote sensing of gas emission. OSAS is a new methodology to evaluate gas concentration emission from spectrally integrated differential absorption measurements. Proof of concept of OSAS-Lidar for CH4 emission monitoring is here presented.

  18. Remote sensing of methane emissions by combining optical similitude absorption spectroscopy (OSAS) and lidar

    Science.gov (United States)

    Galtier, Sandrine; Anselmo, Christophe; Welschinger, Jean-Yves; Cariou, Jean-Pierre; Sivignon, Jean-François; Miffre, Alain; Rairoux, Patrick

    2018-04-01

    Monitoring the emission of gases is difficult to achieve in industrial sites and in environments presenting poor infrastructures. Hence, robust methodologies should be developed and coupled to Lidar technology to allow remote sensing of gas emission. OSAS is a new methodology to evaluate gas concentration emission from spectrally integrated differential absorption measurements. Proof of concept of OSAS-Lidar for CH4 emission monitoring is here presented.

  19. Generic methodology for calibrating profiling nacelle lidars

    DEFF Research Database (Denmark)

    Borraccino, Antoine; Courtney, Michael; Wagner, Rozenn

    Improving power performance assessment by measuring at different heights has been demonstrated using ground-based profiling LIDARs. More recently, nacelle-mounted lidars studies have shown promising capabilities to assess power performance. Using nacelle lidars avoids the erection of expensive me...

  20. Lidar extinction measurement in the mid infrared

    Science.gov (United States)

    Mitev, Valentin; Babichenko, S.; Borelli, R.; Fiorani, L.; Grigorov, I.; Nuvoli, M.; Palucci, A.; Pistilli, M.; Puiu, Ad.; Rebane, Ott; Santoro, S.

    2014-11-01

    We present a lidar measurement of atmospheric extinction coefficient. The measurement is performed by inversion of the backscatter lidar signal at wavelengths 3'000nm and 3'500nm. The inversion of the backscatter lidar signal was performed with constant extinction-to-backscatter ration values of 104 and exponential factor 0.1.

  1. Lidar sounding of volcanic plumes

    Science.gov (United States)

    Fiorani, Luca; Aiuppa, Alessandro; Angelini, Federico; Borelli, Rodolfo; Del Franco, Mario; Murra, Daniele; Pistilli, Marco; Puiu, Adriana; Santoro, Simone

    2013-10-01

    Accurate knowledge of gas composition in volcanic plumes has high scientific and societal value. On the one hand, it gives information on the geophysical processes taking place inside volcanos; on the other hand, it provides alert on possible eruptions. For this reasons, it has been suggested to monitor volcanic plumes by lidar. In particular, one of the aims of the FP7 ERC project BRIDGE is the measurement of CO2 concentration in volcanic gases by differential absorption lidar. This is a very challenging task due to the harsh environment, the narrowness and weakness of the CO2 absorption lines and the difficulty to procure a suitable laser source. This paper, after a review on remote sensing of volcanic plumes, reports on the current progress of the lidar system.

  2. The impact of lidar elevation uncertainty on mapping intertidal habitats on barrier islands

    Science.gov (United States)

    Enwright, Nicholas M.; Wang, Lei; Borchert, Sinéad M.; Day, Richard H.; Feher, Laura C.; Osland, Michael J.

    2018-01-01

    While airborne lidar data have revolutionized the spatial resolution that elevations can be realized, data limitations are often magnified in coastal settings. Researchers have found that airborne lidar can have a vertical error as high as 60 cm in densely vegetated intertidal areas. The uncertainty of digital elevation models is often left unaddressed; however, in low-relief environments, such as barrier islands, centimeter differences in elevation can affect exposure to physically demanding abiotic conditions, which greatly influence ecosystem structure and function. In this study, we used airborne lidar elevation data, in situ elevation observations, lidar metadata, and tide gauge information to delineate low-lying lands and the intertidal wetlands on Dauphin Island, a barrier island along the coast of Alabama, USA. We compared three different elevation error treatments, which included leaving error untreated and treatments that used Monte Carlo simulations to incorporate elevation vertical uncertainty using general information from lidar metadata and site-specific Real-Time Kinematic Global Position System data, respectively. To aid researchers in instances where limited information is available for error propagation, we conducted a sensitivity test to assess the effect of minor changes to error and bias. Treatment of error with site-specific observations produced the fewest omission errors, although the treatment using the lidar metadata had the most well-balanced results. The percent coverage of intertidal wetlands was increased by up to 80% when treating the vertical error of the digital elevation models. Based on the results from the sensitivity analysis, it could be reasonable to use error and positive bias values from literature for similar environments, conditions, and lidar acquisition characteristics in the event that collection of site-specific data is not feasible and information in the lidar metadata is insufficient. The methodology presented in

  3. Lidar configurations for wind turbine control

    DEFF Research Database (Denmark)

    Mirzaei, Mahmood; Mann, Jakob

    2016-01-01

    Lidar sensors have proved to be very beneficial in the wind energy industry. They can be used for yaw correction, feed-forward pitch control and load verification. However, the current lidars are expensive. One way to reduce the price is to use lidars with few measurement points. Finding the best...... by the lidar is compared against the effective wind speed on a wind turbine rotor both theoretically and through simulations. The study provides some results to choose the best configuration of the lidar with few measurement points....

  4. High-Rate Data-Capture for an Airborne Lidar System

    Science.gov (United States)

    Valett, Susan; Hicks, Edward; Dabney, Philip; Harding, David

    2012-01-01

    A high-rate data system was required to capture the data for an airborne lidar system. A data system was developed that achieved up to 22 million (64-bit) events per second sustained data rate (1408 million bits per second), as well as short bursts (less than 4 s) at higher rates. All hardware used for the system was off the shelf, but carefully selected to achieve these rates. The system was used to capture laser fire, single-photon detection, and GPS data for the Slope Imaging Multi-polarization Photo-counting Lidar (SIMPL). However, the system has applications for other laser altimeter systems (waveform-recording), mass spectroscopy, xray radiometry imaging, high-background- rate ranging lidar, and other similar areas where very high-speed data capture is needed. The data capture software was used for the SIMPL instrument that employs a micropulse, single-photon ranging measurement approach and has 16 data channels. The detected single photons are from two sources those reflected from the target and solar background photons. The instrument is non-gated, so background photons are acquired for a range window of 13 km and can comprise many times the number of target photons. The highest background rate occurs when the atmosphere is clear, the Sun is high, and the target is a highly reflective surface such as snow. Under these conditions, the total data rate for the 16 channels combined is expected to be approximately 22 million events per second. For each photon detection event, the data capture software reads the relative time of receipt, with respect to a one-per-second absolute time pulse from a GPS receiver, from an event timer card with 0.1-ns precision, and records that information to a RAID (Redundant Array of Independent Disks) storage device. The relative time of laser pulse firings must also be read and recorded with the same precision. Each of the four event timer cards handles the throughput from four of the channels. For each detection event, a flag is

  5. Semiconductor Laser Wind Lidar for Turbine Control

    DEFF Research Database (Denmark)

    Hu, Qi

    This thesis describes an experimentally oriented study of continuous wave (CW) coherent Doppler lidar system design. The main application is remote wind sensing for active wind turbine control using nacelle mounted lidar systems; and the primary focus is to devise an industrial instrument that can...... historical overview within the topic of wind lidar systems. Both the potential and the challenges of an industrialized wind lidar has been addressed here. Furthermore, the basic concept behind the heterodyne detection and a brief overview of the lidar signal processing is explained; and a simple...... investigation of the telescope truncation and lens aberrations is conducted, both numerically and experimentally. It is shown that these parameters dictate the spatial resolution of the lidar system, and have profound impact on the SNR. In this work, an all-semiconductor light source is used in the lidar design...

  6. Lidar Observations of Tropospheric Aerosols Over Northeastern South Africa During the ARREX and SAFARI-2000 Dry Season Experiments

    Science.gov (United States)

    Campbell, James R.; Welton, Ellsworth J.; Spinhirne, James D.; Ji, Qiang; Tsay, Si-Chee; Piketh, Stuart J.; Barenbrug, Marguerite; Holben, Brent; Starr, David OC. (Technical Monitor)

    2002-01-01

    During the ARREX-1999 and SAFARI-2000 Dry Season experiments a micropulse lidar (523 nm) instrument was operated at the Skukuza Airport in northeastern South Africa. The Mar was collocated with a diverse array of passive radiometric equipment. For SAFARI-2000 the processed Mar data yields a daytime time-series of layer mean/derived aerosol optical properties, including extinction-to-backscatter ratios and vertical extinction cross-section profile. Combined with 523 run aerosol optical depth and spectral Angstrom exponent calculations from available CIMEL sun-photometer data and normalized broadband flux measurements the temporal evolution of the near surface aerosol layer optical properties is analyzed for climatological trends. For the densest smoke/haze events the extinction-to-backscatter ratio is found to be between 60-80/sr, and corresponding Angstrom exponent calculations near and above 1.75. The optical characteristics of an evolving smoke event from SAFARI-2000 are extensively detailed. The advecting smoke was embedded within two distinct stratified thermodynamic layers, causing the particulate mass to advect over the instrument array in an incoherent manner on the afternoon of its occurrence. Surface broadband flux forcing due to the smoke is calculated, as is the evolution in the vertical aerosol extinction profile as measured by the Han Finally, observations of persistent elevated aerosol during ARREX-1999 are presented and discussed. The lack of corroborating observations the following year makes these observation; both unique and noteworthy in the scope of regional aerosol transport over southern Africa.

  7. Lidar aboveground vegetation biomass estimates in shrublands: Prediction, uncertainties and application to coarser scales

    Science.gov (United States)

    Li, Aihua; Dhakal, Shital; Glenn, Nancy F.; Spaete, Luke P.; Shinneman, Douglas; Pilliod, David S.; Arkle, Robert; McIlroy, Susan

    2017-01-01

    Our study objectives were to model the aboveground biomass in a xeric shrub-steppe landscape with airborne light detection and ranging (Lidar) and explore the uncertainty associated with the models we created. We incorporated vegetation vertical structure information obtained from Lidar with ground-measured biomass data, allowing us to scale shrub biomass from small field sites (1 m subplots and 1 ha plots) to a larger landscape. A series of airborne Lidar-derived vegetation metrics were trained and linked with the field-measured biomass in Random Forests (RF) regression models. A Stepwise Multiple Regression (SMR) model was also explored as a comparison. Our results demonstrated that the important predictors from Lidar-derived metrics had a strong correlation with field-measured biomass in the RF regression models with a pseudo R2 of 0.76 and RMSE of 125 g/m2 for shrub biomass and a pseudo R2 of 0.74 and RMSE of 141 g/m2 for total biomass, and a weak correlation with field-measured herbaceous biomass. The SMR results were similar but slightly better than RF, explaining 77–79% of the variance, with RMSE ranging from 120 to 129 g/m2 for shrub and total biomass, respectively. We further explored the computational efficiency and relative accuracies of using point cloud and raster Lidar metrics at different resolutions (1 m to 1 ha). Metrics derived from the Lidar point cloud processing led to improved biomass estimates at nearly all resolutions in comparison to raster-derived Lidar metrics. Only at 1 m were the results from the point cloud and raster products nearly equivalent. The best Lidar prediction models of biomass at the plot-level (1 ha) were achieved when Lidar metrics were derived from an average of fine resolution (1 m) metrics to minimize boundary effects and to smooth variability. Overall, both RF and SMR methods explained more than 74% of the variance in biomass, with the most important Lidar variables being associated with vegetation structure

  8. 2013 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Tulalip Partnership

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In October 2012, WSI (Watershed Sciences, Inc.) was contracted by the Puget Sound LiDAR Consortium (PSLC)to collect Light Detection and Ranging (LiDAR) data on a...

  9. 2014 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Willapa Valley (Delivery 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In January, 2014 WSI, a Quantum Spatial (QSI) company, was contracted by the Puget Sound LiDAR Consortium (PSLC) to collect Light Detection and Ranging (LiDAR) data...

  10. 2013 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Saddle Mountain

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In October 2013, WSI, a Quantum Spatial Company (QSI), was contracted by the Puget Sound LiDAR Consortium (PSLC) to collect Light Detection and Ranging (LiDAR) data...

  11. 2015 Puget Sound LiDAR Consortium (PSLC) LiDAR: WA DNR Lands (P2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In June 2014, WSI, a Quantum Spatial Inc. (QSI) company, was contracted by the Puget Sound LiDAR Consortium (PSLC) to collect Light Detection and Ranging (LiDAR)...

  12. 2015 Puget Sound LiDAR Consortium (PSLC) LiDAR: WA DNR Lands (P1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In June 2014, WSI, a Quantum Spatial Inc. (QSI) company, was contracted by the Puget Sound LiDAR Consortium (PSLC) to collect Light Detection and Ranging (LiDAR)...

  13. 2012 MEGIS Topographic Lidar: Statewide Lidar Project Area 1 (Aroostook), Maine

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — LiDAR data is a remotely sensed high resolution elevation data collected by an airborne platform. The LiDAR sensor uses a combination of laser range finding, GPS...

  14. 2009 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Lewis County, Washington

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. (WSI) collected Light Detection and Ranging (LiDAR) data for the Lewis County survey area for the Puget Sound LiDAR Consortium. This data...

  15. 2012 MEGIS Topographic Lidar: Statewide Lidar Project Areas 2 and 3 (Mid-Coastal Cleanup), Maine

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — LiDAR data is a remotely sensed high resolution elevation data collected by an airborne platform. The LiDAR sensor uses a combination of laser range finding, GPS...

  16. Advancing Lidar Sensors Technologies for Next Generation Landing Missions

    Science.gov (United States)

    Amzajerdian, Farzin; Hines, Glenn D.; Roback, Vincent E.; Petway, Larry B.; Barnes, Bruce W.; Brewster, Paul F.; Pierrottet, Diego F.; Bulyshev, Alexander

    2015-01-01

    Missions to solar systems bodies must meet increasingly ambitious objectives requiring highly reliable "precision landing", and "hazard avoidance" capabilities. Robotic missions to the Moon and Mars demand landing at pre-designated sites of high scientific value near hazardous terrain features, such as escarpments, craters, slopes, and rocks. Missions aimed at paving the path for colonization of the Moon and human landing on Mars need to execute onboard hazard detection and precision maneuvering to ensure safe landing near previously deployed assets. Asteroid missions require precision rendezvous, identification of the landing or sampling site location, and navigation to the highly dynamic object that may be tumbling at a fast rate. To meet these needs, NASA Langley Research Center (LaRC) has developed a set of advanced lidar sensors under the Autonomous Landing and Hazard Avoidance Technology (ALHAT) project. These lidar sensors can provide precision measurement of vehicle relative proximity, velocity, and orientation, and high resolution elevation maps of the surface during the descent to the targeted body. Recent flights onboard Morpheus free-flyer vehicle have demonstrated the viability of ALHAT lidar sensors for future landing missions to solar system bodies.

  17. Lidar investigations of atmospheric aerosols over Sofia

    International Nuclear Information System (INIS)

    Dreischuh, T.; Deleva, A.; Peshev, Z.; Grigorov, I.; Kolarov, G.; Stoyanov, D.

    2016-01-01

    An overview is given of the laser remote sensing of atmospheric aerosols and related processes over the Sofia area performed in the Institute of Electronics, Bulgarian Academy of Sciences, during the last three years. Results from lidar investigations of the optical characteristics of atmospheric aerosols obtained in the frame of the European Aerosol Research Lidar Network, as well as from the lidar mapping of near-surface aerosol fields for remote monitoring of atmospheric pollutants are presented and discussed in this paper.

  18. Lidar data used in the COFIN project

    DEFF Research Database (Denmark)

    Ejsing Jørgensen, Hans; Nielsen, Morten

    1999-01-01

    This report presents the Lidar data used in the COFIN project. The Lidar data have been obtained from several ground level dispersion experiments over flat and complex terrain. The method for treating the data and the conditons under which the data wereobtained are described in detail. Finally we...... describe the Tools to extract and visualize the Lidar data. Data, report, and visualisation tools are available on the Risø FTP server....

  19. Doppler Lidar Vertical Velocity Statistics Value-Added Product

    Energy Technology Data Exchange (ETDEWEB)

    Newsom, R. K. [DOE ARM Climate Research Facility, Washington, DC (United States); Sivaraman, C. [DOE ARM Climate Research Facility, Washington, DC (United States); Shippert, T. R. [DOE ARM Climate Research Facility, Washington, DC (United States); Riihimaki, L. D. [DOE ARM Climate Research Facility, Washington, DC (United States)

    2015-07-01

    Accurate height-resolved measurements of higher-order statistical moments of vertical velocity fluctuations are crucial for improved understanding of turbulent mixing and diffusion, convective initiation, and cloud life cycles. The Atmospheric Radiation Measurement (ARM) Climate Research Facility operates coherent Doppler lidar systems at several sites around the globe. These instruments provide measurements of clear-air vertical velocity profiles in the lower troposphere with a nominal temporal resolution of 1 sec and height resolution of 30 m. The purpose of the Doppler lidar vertical velocity statistics (DLWSTATS) value-added product (VAP) is to produce height- and time-resolved estimates of vertical velocity variance, skewness, and kurtosis from these raw measurements. The VAP also produces estimates of cloud properties, including cloud-base height (CBH), cloud frequency, cloud-base vertical velocity, and cloud-base updraft fraction.

  20. Imaging Flash Lidar for Safe Landing on Solar System Bodies and Spacecraft Rendezvous and Docking

    Science.gov (United States)

    Amzajerdian, Farzin; Roback, Vincent E.; Bulyshev, Alexander E.; Brewster, Paul F.; Carrion, William A; Pierrottet, Diego F.; Hines, Glenn D.; Petway, Larry B.; Barnes, Bruce W.; Noe, Anna M.

    2015-01-01

    NASA has been pursuing flash lidar technology for autonomous, safe landing on solar system bodies and for automated rendezvous and docking. During the final stages of the landing from about 1 kilometer to 500 meters above the ground, the flash lidar can generate 3-Dimensional images of the terrain to identify hazardous features such as craters, rocks, and steep slopes. The onboard flight computer can then use the 3-D map of terrain to guide the vehicle to a safe location. As an automated rendezvous and docking sensor, the flash lidar can provide relative range, velocity, and bearing from an approaching spacecraft to another spacecraft or a space station. NASA Langley Research Center has developed and demonstrated a flash lidar sensor system capable of generating 16,000 pixels range images with 7 centimeters precision, at 20 Hertz frame rate, from a maximum slant range of 1800 m from the target area. This paper describes the lidar instrument and presents the results of recent flight tests onboard a rocket-propelled free-flyer vehicle (Morpheus) built by NASA Johnson Space Center. The flights were conducted at a simulated lunar terrain site, consisting of realistic hazard features and designated landing areas, built at NASA Kennedy Space Center specifically for this demonstration test. This paper also provides an overview of the plan for continued advancement of the flash lidar technology aimed at enhancing its performance to meet both landing and automated rendezvous and docking applications.

  1. GRIP LIDAR ATMOSPHERIC SENSING EXPERIMENT (LASE) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GRIP Lidar Atmospheric Sensing Experiment (LASE) dataset was collected by NASA's Lidar Atmospheric Sensing Experiment (LASE) system, which is an airborne...

  2. NAMMA LIDAR ATMOSPHERIC SENSING EXPERIMENT (LASE) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA's Lidar Atmospheric Sensing Experiment (LASE) system using the DIAL (Differential Absorption Lidar) system was operated during the NASA African Monsoon...

  3. SAR and LIDAR fusion: experiments and applications

    Science.gov (United States)

    Edwards, Matthew C.; Zaugg, Evan C.; Bradley, Joshua P.; Bowden, Ryan D.

    2013-05-01

    In recent years ARTEMIS, Inc. has developed a series of compact, versatile Synthetic Aperture Radar (SAR) systems which have been operated on a variety of small manned and unmanned aircraft. The multi-frequency-band SlimSAR has demonstrated a variety of capabilities including maritime and littoral target detection, ground moving target indication, polarimetry, interferometry, change detection, and foliage penetration. ARTEMIS also continues to build upon the radar's capabilities through fusion with other sensors, such as electro-optical and infrared camera gimbals and light detection and ranging (LIDAR) devices. In this paper we focus on experiments and applications employing SAR and LIDAR fusion. LIDAR is similar to radar in that it transmits a signal which, after being reflected or scattered by a target area, is recorded by the sensor. The differences are that a LIDAR uses a laser as a transmitter and optical sensors as a receiver, and the wavelengths used exhibit a very different scattering phenomenology than the microwaves used in radar, making SAR and LIDAR good complementary technologies. LIDAR is used in many applications including agriculture, archeology, geo-science, and surveying. Some typical data products include digital elevation maps of a target area and features and shapes extracted from the data. A set of experiments conducted to demonstrate the fusion of SAR and LIDAR data include a LIDAR DEM used in accurately processing the SAR data of a high relief area (mountainous, urban). Also, feature extraction is used in improving geolocation accuracy of the SAR and LIDAR data.

  4. Enlarged pores treated with a combination of Q-switched and micropulsed 1064 nm Nd:YAG laser with and without topical carbon suspension: A simultaneous split-face trial.

    Science.gov (United States)

    Chung, Hj; Goo, Bc; Lee, Hj; Roh, Mr; Chung, Ky

    2011-01-01

    Enlarged facial pores remain one of the major cosmetic concerns among Asian females. This study attempted to assess and compare the efficacy of a combination of the Q-switched and quasi long-pulsed (micropulsed) Nd:YAG laser to reduce the size of the enlarged pores with and without an exogenous photoenhancer. In twenty five female subjects mean age 34.04 yr and skin type II-IV, a carbon lotion as a photoenhancer was applied on one side of the face (Method 1) and the other side was used as the control (Method 2). The entire face was then treated with a single pass of the 1064 nm Nd:YAG laser in the micropulsed mode, pulse fluence and width of 2.3 J/cm(2) and 300 µsec, respectively. Multiple passes were then delivered in the Q-switched mode (2.5 J/cm(2) and 5 nsec). Three weeks after the final treatment, 75% of the subjects showed improvement with method 1 whereas 67% showed improvement with method 2. No adverse side effects were reported with either method. Although histological confirmation was not performed, we were able to prove both subjectively and objectively that the use of the combination of the micropulsed and Q-switched modes of the Nd:YAG laser was useful in reducing pore size, and that the photoenhancer improved the efficacy.

  5. Quantifying Vegetation Structure with Lightweight, Rapid-Scanning Terrestrial Lidar

    Science.gov (United States)

    Paynter, I.; Genest, D.; Saenz, E. J.; Strahler, A. H.; Li, Z.; Peri, F.; Schaaf, C.

    2016-12-01

    Light Detection and Ranging (lidar) is proving a competent technology for observing vegetation structure. Terrestrial laser scanners (TLS) are ground-based instruments which utilize hundreds of thousands to millions of lidar observations to provide detailed structural and reflective information of their surroundings. TLS has enjoyed initial success as a validation tool for satellite and airborne estimates of vegetation structure, and are producing independent estimates with increasing accuracy. Reconstruction techniques for TLS observations of vegetation have also improved rapidly, especially for trees. However, uncertainties and challenges still remain in TLS modelling of vegetation structure, especially in geometrically complex ecosystems such as tropical forests (where observation extent and density is hampered by occlusion) and highly temporally dynamic coastal ecosystems (such as saltmarshes and mangroves), where observations may be restricted to narrow microstates. Some of these uncertainties can be mitigated, and challenges met, through the use of lidar instruments optimized for favorable deployment logistics through low weight, rapid scanning, and improved durability. We have conducted studies of vegetation structure in temperate and tropical forests, saltmarshes and mangroves, utilizing a highly portable TLS with considerable deployment flexibility, the Compact Biomass Lidar (CBL). We show results from studies in the temperate Long Term Ecological Research site of Harvard Forest (MA, USA); the tropical forested long-term Carbono sites of La Selva Biological Station (Sarapiqui, Costa Rica); and the saltmarsh LTER of Plum Island (MA, USA). These results demonstrate the improvements to observations in these ecosystems which are facilitated by the specifications of the CBL (and similar TLS) which are optimized for favorable deployment logistics and flexibility. We show the benefits of increased numbers of scanning positions, and specialized deployment

  6. Three-dimension imaging lidar

    Science.gov (United States)

    Degnan, John J. (Inventor)

    2007-01-01

    This invention is directed to a 3-dimensional imaging lidar, which utilizes modest power kHz rate lasers, array detectors, photon-counting multi-channel timing receivers, and dual wedge optical scanners with transmitter point-ahead correction to provide contiguous high spatial resolution mapping of surface features including ground, water, man-made objects, vegetation and submerged surfaces from an aircraft or a spacecraft.

  7. Lidar observations of marine boundary-layer winds and heights: a preliminary study

    DEFF Research Database (Denmark)

    Peña, Alfredo; Gryning, Sven-Erik; Floors, Rogier Ralph

    2015-01-01

    the highest data availability (among the three sites) and a very good agreement with the observations of wind speed and direction from cup anemometers and vanes from the platform's tower. The wind lidar was also able to perform measurements under a winter storm where 10-s gusts were observed above 60 m s 1......Here we describe a nearly 1-yr meteorological campaign, which was carried out at the FINO3 marine research platform on the German North Sea, where a pulsed wind lidar and a ceilometer were installed besides the platform's 105-m tower and measured winds and the aerosol backscatter in the entire...... marine atmospheric boundary layer. The campaign was the last phase of a research project, in which the vertical wind profile in the atmospheric boundary layer was firstly investigated on a coastal and a semi-urban site. At FINO3 the wind lidar, which measures the wind speed up to 2000 m, shows...

  8. Lidar and Hyperspectral Remote Sensing for the Analysis of Coniferous Biomass Stocks and Fluxes

    Science.gov (United States)

    Halligan, K. Q.; Roberts, D. A.

    2006-12-01

    Airborne lidar and hyperspectral data can improve estimates of aboveground carbon stocks and fluxes through their complimentary responses to vegetation structure and biochemistry. While strong relationships have been demonstrated between lidar-estimated vegetation structural parameters and field data, research is needed to explore the portability of these methods across a range of topographic conditions, disturbance histories, vegetation type and climate. Additionally, research is needed to evaluate contributions of hyperspectral data in refining biomass estimates and determination of fluxes. To address these questions we are a conducting study of lidar and hyperspectral remote sensing data across sites including coniferous forests, broadleaf deciduous forests and a tropical rainforest. Here we focus on a single study site, Yellowstone National Park, where tree heights, stem locations, above ground biomass and basal area were mapped using first-return small-footprint lidar data. A new method using lidar intensity data was developed for separating the terrain and vegetation components in lidar data using a two-scale iterative local minima filter. Resulting Digital Terrain Models (DTM) and Digital Canopy Models (DCM) were then processed to retrieve a diversity of vertical and horizontal structure metrics. Univariate linear models were used to estimate individual tree heights while stepwise linear regression was used to estimate aboveground biomass and basal area. Three small-area field datasets were compared for their utility in model building and validation of vegetation structure parameters. All structural parameters were linearly correlated with lidar-derived metrics, with higher accuracies obtained where field and imagery data were precisely collocated . Initial analysis of hyperspectral data suggests that vegetation health metrics including measures of live and dead vegetation and stress indices may provide good indicators of carbon flux by mapping vegetation

  9. Development of lidar techniques for environmental studies

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Mats

    1996-09-01

    The lidar group in Lund has performed many DIAL measurements with a mobile lidar system that was first described in 1987. The lidar system is based on a Nd:YAG-pumped dye laser. During the last few years the lidar group has focused on fluorescence imaging and mercury measurements in the troposphere. In 1994 we performed two campaigns: one fluorescence imaging measurement campaign outside Avignon, France and one unique lidar campaign at a mercury mine in Almaden, Spain. Both campaigns are described in this thesis. This thesis also describes how the mobile lidar system was updated with the graphical programming language LabVIEW to obtain a user friendly lidar system. The software controls the lidar system and analyses measured data. The measurement results are shown as maps of species concentration. All electronics and the major parts of the program are described. A new graphical technique to estimate wind speed from plumes is also discussed. First measurements have been performed with the new system. 31 refs, 19 figs, 1 tab

  10. 2013 NRCS-USGS Lidar: Lauderdale (MS)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME:NRCS LAUDERDALE MS 0.7M NPS LIDAR. LiDAR Data Acquisition and Processing Production Task. USGS Contract No. G10PC00057. Task Order No. G12PD000125 Woolpert...

  11. Infrastructure Investment Protection with LiDAR

    Science.gov (United States)

    2012-10-15

    The primary goal of this research effort was to explore the wide variety of uses of LiDAR technology and to evaluate their : applicability to NCDOT practices. NCDOT can use this information about LiDAR in determining how and when the : technology can...

  12. The ITER Thomson scattering core LIDAR diagnostic

    NARCIS (Netherlands)

    Naylor, G.A.; Scannell, R.; Beurskens, M.; Walsh, M.J.; Pastor, I.; Donné, A.J.H.; Snijders, B.; Biel, W.; Meszaros, B.; Giudicotti, L.; Pasqualotto, R.; Marot, L.

    2012-01-01

    The central electron temperature and density of the ITER plasma may be determined by Thomson scattering. A LIDAR topology is proposed in order to minimize the port access required of the ITER vacuum vessel. By using a LIDAR technique, a profile of the electron temperature and density can be

  13. Saginaw Bay, MI LiDAR

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME:(NRCS) Saginaw Bay, MI LiDAR LiDAR Data Acquisition and Processing Production Task USGS Contract No. G10PC00057 Task Order No. G11PD01254 Woolpert Order...

  14. 2012 USGS Lidar: Elwha River (WA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: Elwha River, WA LiDAR LiDAR Data Acquisition and Processing Production Task USGS Contract No. G10PC00057 Task Order No. G11PD01088 Woolpert Order No....

  15. 2006 South Carolina DNR Lidar: Aiken County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The LiDAR data acquisition was executed in five sessions, on March 15, 16 & 17, 2006, using a Leica ALS50 LiDAR System. Specific details about the ALS50 system...

  16. 2014 USGS/NRCS Lidar: Central MS

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: USGS-NRCS Laurel MS 0.7m NPS LIDAR Lidar Data Acquisition and Processing Production Task USGS Contract No. G10PC00057 Task Order No. G13PD01086 Woolpert...

  17. The long term stability of lidar calibrations

    DEFF Research Database (Denmark)

    Courtney, Michael; Gayle Nygaard, Nicolai

    Wind lidars are now used extensively for wind resource measurements. One of the requirements for the data to be accepted in support of project financing (so-called ‘banka-bility’) is to demonstrate the long-term stability of lidar cali-brations. Calibration results for six Leosphere WindCube li...

  18. Airborne Lidar Simulator for the Lidar Surface Topography (LIST) Mission

    Science.gov (United States)

    Yu, Anthony W.; Krainak, Michael A.; Abshire, James B.; Cavanaugh, John; Valett, Susan; Ramos-Izquierdo, Luis

    2010-01-01

    In 2007, the National Research Council (NRC) completed its first decadal survey for Earth science at the request of NASA, NOAA, and USGS. The Lidar Surface Topography (LIST) mission is one of fifteen missions recommended by NRC, whose primary objectives are to map global topography and vegetation structure at 5 m spatial resolution, and to acquire global surface height mapping within a few years. NASA Goddard conducted an initial mission concept study for the LIST mission in 2007, and developed the initial measurement requirements for the mission.

  19. Pointing Verification Method for Spaceborne Lidars

    Directory of Open Access Journals (Sweden)

    Axel Amediek

    2017-01-01

    Full Text Available High precision acquisition of atmospheric parameters from the air or space by means of lidar requires accurate knowledge of laser pointing. Discrepancies between the assumed and actual pointing can introduce large errors due to the Doppler effect or a wrongly assumed air pressure at ground level. In this paper, a method for precisely quantifying these discrepancies for airborne and spaceborne lidar systems is presented. The method is based on the comparison of ground elevations derived from the lidar ranging data with high-resolution topography data obtained from a digital elevation model and allows for the derivation of the lateral and longitudinal deviation of the laser beam propagation direction. The applicability of the technique is demonstrated by using experimental data from an airborne lidar system, confirming that geo-referencing of the lidar ground spot trace with an uncertainty of less than 10 m with respect to the used digital elevation model (DEM can be obtained.

  20. VEHICLE LOCALIZATION BY LIDAR POINT CORRELATION IMPROVED BY CHANGE DETECTION

    Directory of Open Access Journals (Sweden)

    A. Schlichting

    2016-06-01

    Full Text Available LiDAR sensors are proven sensors for accurate vehicle localization. Instead of detecting and matching features in the LiDAR data, we want to use the entire information provided by the scanners. As dynamic objects, like cars, pedestrians or even construction sites could lead to wrong localization results, we use a change detection algorithm to detect these objects in the reference data. If an object occurs in a certain number of measurements at the same position, we mark it and every containing point as static. In the next step, we merge the data of the single measurement epochs to one reference dataset, whereby we only use static points. Further, we also use a classification algorithm to detect trees. For the online localization of the vehicle, we use simulated data of a vertical aligned automotive LiDAR sensor. As we only want to use static objects in this case as well, we use a random forest classifier to detect dynamic scan points online. Since the automotive data is derived from the LiDAR Mobile Mapping System, we are able to use the labelled objects from the reference data generation step to create the training data and further to detect dynamic objects online. The localization then can be done by a point to image correlation method using only static objects. We achieved a localization standard deviation of about 5 cm (position and 0.06° (heading, and were able to successfully localize the vehicle in about 93 % of the cases along a trajectory of 13 km in Hannover, Germany.

  1. Vehicle Localization by LIDAR Point Correlation Improved by Change Detection

    Science.gov (United States)

    Schlichting, A.; Brenner, C.

    2016-06-01

    LiDAR sensors are proven sensors for accurate vehicle localization. Instead of detecting and matching features in the LiDAR data, we want to use the entire information provided by the scanners. As dynamic objects, like cars, pedestrians or even construction sites could lead to wrong localization results, we use a change detection algorithm to detect these objects in the reference data. If an object occurs in a certain number of measurements at the same position, we mark it and every containing point as static. In the next step, we merge the data of the single measurement epochs to one reference dataset, whereby we only use static points. Further, we also use a classification algorithm to detect trees. For the online localization of the vehicle, we use simulated data of a vertical aligned automotive LiDAR sensor. As we only want to use static objects in this case as well, we use a random forest classifier to detect dynamic scan points online. Since the automotive data is derived from the LiDAR Mobile Mapping System, we are able to use the labelled objects from the reference data generation step to create the training data and further to detect dynamic objects online. The localization then can be done by a point to image correlation method using only static objects. We achieved a localization standard deviation of about 5 cm (position) and 0.06° (heading), and were able to successfully localize the vehicle in about 93 % of the cases along a trajectory of 13 km in Hannover, Germany.

  2. Calibration Methods for a Space Borne Backscatter Lidar

    NARCIS (Netherlands)

    Kunz, G.J.

    1996-01-01

    Lidar returns from cloud decks and from the Earth's surface are useful for calibrating single scatter lidar signals from space. To this end analytical methods (forward and backward) are presented for inverting lidar waveforms in terms of the path integrated lidar retum and the transmission losses

  3. Measurement and Study of Lidar Ratio by Using a Raman Lidar in Central China

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2016-05-01

    Full Text Available We comprehensively evaluated particle lidar ratios (i.e., particle extinction to backscatter ratio at 532 nm over Wuhan in Central China by using a Raman lidar from July 2013 to May 2015. We utilized the Raman lidar data to obtain homogeneous aerosol lidar ratios near the surface through the Raman method during no-rain nights. The lidar ratios were approximately 57 ± 7 sr, 50 ± 5 sr, and 22 ± 4 sr under the three cases with obviously different pollution levels. The haze layer below 1.8 km has a large particle extinction coefficient (from 5.4e-4 m−1 to 1.6e-4 m−1 and particle backscatter coefficient (between 1.1e-05 m−1sr−1 and 1.7e-06 m−1sr−1 in the heavily polluted case. Furthermore, the particle lidar ratios varied according to season, especially between winter (57 ± 13 sr and summer (33 ± 10 sr. The seasonal variation in lidar ratios at Wuhan suggests that the East Asian monsoon significantly affects the primary aerosol types and aerosol optical properties in this region. The relationships between particle lidar ratios and wind indicate that large lidar ratio values correspond well with weak winds and strong northerly winds, whereas significantly low lidar ratio values are associated with prevailing southwesterly and southerly wind.

  4. Measurement and Study of Lidar Ratio by Using a Raman Lidar in Central China.

    Science.gov (United States)

    Wang, Wei; Gong, Wei; Mao, Feiyue; Pan, Zengxin; Liu, Boming

    2016-05-18

    We comprehensively evaluated particle lidar ratios (i.e., particle extinction to backscatter ratio) at 532 nm over Wuhan in Central China by using a Raman lidar from July 2013 to May 2015. We utilized the Raman lidar data to obtain homogeneous aerosol lidar ratios near the surface through the Raman method during no-rain nights. The lidar ratios were approximately 57 ± 7 sr, 50 ± 5 sr, and 22 ± 4 sr under the three cases with obviously different pollution levels. The haze layer below 1.8 km has a large particle extinction coefficient (from 5.4e-4 m(-1) to 1.6e-4 m(-1)) and particle backscatter coefficient (between 1.1e-05 m(-1)sr(-1) and 1.7e-06 m(-1)sr(-1)) in the heavily polluted case. Furthermore, the particle lidar ratios varied according to season, especially between winter (57 ± 13 sr) and summer (33 ± 10 sr). The seasonal variation in lidar ratios at Wuhan suggests that the East Asian monsoon significantly affects the primary aerosol types and aerosol optical properties in this region. The relationships between particle lidar ratios and wind indicate that large lidar ratio values correspond well with weak winds and strong northerly winds, whereas significantly low lidar ratio values are associated with prevailing southwesterly and southerly wind.

  5. Test of ground-based Lidar instrument WLS200S-10

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula

    This report presents the result of the test performed for the given Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. The test aims at establishing a relation between the reference wind measurements and corresponding lidar wind indications, and evaluating a set of quality...

  6. Test of ground-based Lidar instrument WLS200S-11

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula

    This report presents the result of the test performed for the given Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. The test aims at establishing a relation between the reference wind measurements and corresponding lidar wind indications, and evaluating a set of quality...

  7. Test of ground-based Lidar instrument WLS7-106

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula

    This report presents the result of the test performed for the given Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. The test aims at establishing a relation between the reference wind measurements and corresponding lidar wind indications, and evaluating a set of quality...

  8. Test of ground-based lidar instrument WLS7-159

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Wagner, Rozenn

    This report presents the result of the test performed for the given Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. The test aims at establishing a relation between the reference wind measurements and corresponding lidar wind indications, and evaluating a set of quality...

  9. Calibration of ground-based Lidar instrument WLS7-73

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain...

  10. Improving Aerosol and Visibility Forecasting Capabilities Using Current and Future Generations of Satellite Observations

    Science.gov (United States)

    2015-08-27

    using ground observations from the NASA Aerosol Robotic Network (AERGNET) and the Micropulse Lidar Network (MPLNET). APPROACH To achieve the...as well as column-integrated x from one High Spectral Resolution Lidar (HSRL) site at Huntsville, AL during the NASA Studies of Emissions and...which was built in FY14, has been tested with GOES-13 data. Figure la shows the gridded (l0xl0 Latitude, Longitude) GOES radiance data from cloud

  11. Improving salt marsh digital elevation model accuracy with full-waveform lidar and nonparametric predictive modeling

    Science.gov (United States)

    Rogers, Jeffrey N.; Parrish, Christopher E.; Ward, Larry G.; Burdick, David M.

    2018-03-01

    Salt marsh vegetation tends to increase vertical uncertainty in light detection and ranging (lidar) derived elevation data, often causing the data to become ineffective for analysis of topographic features governing tidal inundation or vegetation zonation. Previous attempts at improving lidar data collected in salt marsh environments range from simply computing and subtracting the global elevation bias to more complex methods such as computing vegetation-specific, constant correction factors. The vegetation specific corrections can be used along with an existing habitat map to apply separate corrections to different areas within a study site. It is hypothesized here that correcting salt marsh lidar data by applying location-specific, point-by-point corrections, which are computed from lidar waveform-derived features, tidal-datum based elevation, distance from shoreline and other lidar digital elevation model based variables, using nonparametric regression will produce better results. The methods were developed and tested using full-waveform lidar and ground truth for three marshes in Cape Cod, Massachusetts, U.S.A. Five different model algorithms for nonparametric regression were evaluated, with TreeNet's stochastic gradient boosting algorithm consistently producing better regression and classification results. Additionally, models were constructed to predict the vegetative zone (high marsh and low marsh). The predictive modeling methods used in this study estimated ground elevation with a mean bias of 0.00 m and a standard deviation of 0.07 m (0.07 m root mean square error). These methods appear very promising for correction of salt marsh lidar data and, importantly, do not require an existing habitat map, biomass measurements, or image based remote sensing data such as multi/hyperspectral imagery.

  12. Aerosol observation using multi-wavelength Mie-Raman lidars of the Ad-Net and aerosol component analysis

    Science.gov (United States)

    Nishizawa, Tomoaki; Sugimoto, Nobuo; Shimizu, Atsushi; Uno, Itsushi; Hara, Yukari; Kudo, Rei

    2018-04-01

    We deployed multi-wavelength Mie-Raman lidars (MMRL) at three sites of the AD-Net and have conducted continuous measurements using them since 2013. To analyze the MMRL data and better understand the externally mixing state of main aerosol components (e.g., dust, sea-salt, and black carbon) in the atmosphere, we developed an integrated package of aerosol component retrieval algorithms, which have already been developed or are being developed, to estimate vertical profiles of the aerosol components. This package applies to the other ground-based lidar network data (e.g., EARLINET) and satellite-borne lidar data (e.g., CALIOP/CALIPSO and ATLID/EarthCARE) as well as the other lidar data of the AD-Net.

  13. Aerosol observation using multi-wavelength Mie-Raman lidars of the Ad-Net and aerosol component analysis

    Directory of Open Access Journals (Sweden)

    Nishizawa Tomoaki

    2018-01-01

    Full Text Available We deployed multi-wavelength Mie-Raman lidars (MMRL at three sites of the AD-Net and have conducted continuous measurements using them since 2013. To analyze the MMRL data and better understand the externally mixing state of main aerosol components (e.g., dust, sea-salt, and black carbon in the atmosphere, we developed an integrated package of aerosol component retrieval algorithms, which have already been developed or are being developed, to estimate vertical profiles of the aerosol components. This package applies to the other ground-based lidar network data (e.g., EARLINET and satellite-borne lidar data (e.g., CALIOP/CALIPSO and ATLID/EarthCARE as well as the other lidar data of the AD-Net.

  14. The lidar dark band: An oddity of the radar bright band analogy

    Energy Technology Data Exchange (ETDEWEB)

    Sassen, K. [Univ. of Utah, Salt Lake City, UT (United States)

    1996-04-01

    Although much has sbeen learned from independent radar and lidar studies of atmospheric precipitations, occasionally supported by aircraft profiling, what has been lacking is combined optical, microwave, and insitu observations of the melting layer. Fortunately, the rainshowers on April 21, 1994, during the Remote Cloud Sensing intensive obervations Period (RCSIOP) at the Southern Great Plains Cloud and radiation Testbed (CART) site provided an opportunity for coordinated dual-wavelength University of Utah Polarization Diversity Lidar, University of Massachusetts Cloud Profiling Radar System Doppler Radar, and the University of North Dakota Citation aircraft measurements.

  15. Radar and Lidar Radar DEM

    Science.gov (United States)

    Liskovich, Diana; Simard, Marc

    2011-01-01

    Using radar and lidar data, the aim is to improve 3D rendering of terrain, including digital elevation models (DEM) and estimates of vegetation height and biomass in a variety of forest types and terrains. The 3D mapping of vegetation structure and the analysis are useful to determine the role of forest in climate change (carbon cycle), in providing habitat and as a provider of socio-economic services. This in turn will lead to potential for development of more effective land-use management. The first part of the project was to characterize the Shuttle Radar Topography Mission DEM error with respect to ICESat/GLAS point estimates of elevation. We investigated potential trends with latitude, canopy height, signal to noise ratio (SNR), number of LiDAR waveform peaks, and maximum peak width. Scatter plots were produced for each variable and were fitted with 1st and 2nd degree polynomials. Higher order trends were visually inspected through filtering with a mean and median filter. We also assessed trends in the DEM error variance. Finally, a map showing how DEM error was geographically distributed globally was created.

  16. What Good is Raman Water Vapor Lidar?

    Science.gov (United States)

    Whitman, David

    2011-01-01

    Raman lidar has been used to quantify water vapor in the atmosphere for various scientific studies including mesoscale meteorology and satellite validation. Now the international networks of NDACC and GRUAN have interest in using Raman water vapor lidar for detecting trends in atmospheric water vapor concentrations. What are the data needs for addressing these very different measurement challenges. We will review briefly the scientific needs for water vapor accuracy for each of these three applications and attempt to translate that into performance specifications for Raman lidar in an effort to address the question in the title of "What good is Raman water vapor Iidar."

  17. Multiangle lidar observations of the Atmosphere

    Science.gov (United States)

    Lalitkumar Prakash, Pawar; Choukiker, Yogesh Kumar; Raghunath, K.

    2018-04-01

    Atmospheric Lidars are used extensively to get aerosol parameters like backscatter coefficient, backscatter ratio etc. National Atmospheric Research Laboratory, Gadanki (13°N, 79°E), India has a powerful lidar which has alt-azimuth capability. Inversion method is applied to data from observations of lidar system at different azimuth and elevation angles. Data Analysis is described and Observations in 2D and 3D format are discussed. Presence of Cloud and the variation of backscatter parameters are seen in an interesting manner.

  18. Multiangle lidar observations of the Atmosphere

    Directory of Open Access Journals (Sweden)

    Lalitkumar Prakash Pawar

    2018-01-01

    Full Text Available Atmospheric Lidars are used extensively to get aerosol parameters like backscatter coefficient, backscatter ratio etc. National Atmospheric Research Laboratory, Gadanki (13°N, 79°E, India has a powerful lidar which has alt-azimuth capability. Inversion method is applied to data from observations of lidar system at different azimuth and elevation angles. Data Analysis is described and Observations in 2D and 3D format are discussed. Presence of Cloud and the variation of backscatter parameters are seen in an interesting manner.

  19. Wind measurement via direct detection lidar

    Science.gov (United States)

    Afek, I.; Sela, N.; Narkiss, N.; Shamai, G.; Tsadka, S.

    2013-10-01

    Wind sensing Lidar is considered a promising technology for high quality wind measurements required for various applications such as hub height wind resource assessment, power curve measurements and advanced, real time, forward looking turbine control. Until recently, the only available Lidar technology was based on coherent Doppler shift detection, whose market acceptance has been slow primarily due to its exuberant price. Direct detection Lidar technology provides an alternative to remote sensing of wind by incorporating high precision measurement, a robust design and an affordable price tag.

  20. Detectors for LIDAR type Thomson scattering diagnostics

    International Nuclear Information System (INIS)

    Hirsch, K.

    1991-04-01

    A report on the capability of the microchannel plate photomultiplier type (ITT F4128) presently used at the JET LIDAR Thomson Scattering System is given. Detailed investigation on time response, low noise amplification, shutter ratio, gating behaviour, linear mode of operation and saturation pulse recovery carried out during the design phase for LIDAR are presented. New investigation with respect to dc- and gated operation showed no measurable changes in sensitivity of this MCP photomultiplier. Comparing this type of detector with other MCP photomultipliers and with streak cameras some detection schemes for future LIDAR type diagnostic are proposed. (orig.)

  1. Detecting wind turbine wakes with nacelle lidars

    DEFF Research Database (Denmark)

    Held, D. P.; Larvol, A.; Mann, Jakob

    2017-01-01

    variance is used as a detection parameter for wakes. A one month long measurement campaign, where a continuous-wave lidar on a turbine has been exposed to multiple wake situations, is used to test the detection capabilities. The results show that it is possible to identify situation where a downstream...... turbine is in wake by comparing the peak widths. The used lidar is inexpensive and brings instalments on every turbine within economical reach. Thus, the information gathered by the lidars can be used for improved control at wind farm level....

  2. LIDAR for atmosphere research over Africa

    CSIR Research Space (South Africa)

    Sivakumar, V

    2008-11-01

    Full Text Available d’aéronomie, CNRS, Paris, France 1Email: SVenkataraman@csir.co.za – www.csir.co.za K-6665 [www.kashangroup.com] Lidar for atmospheric studies: The CSIR’s laser research into monitoring various pollutants in the lower atmosphere via... to lidar applications for atmosphere studies including pollutant monitoring. The following salient features emanated from the survey: • Around 80% of the lidars are in the northern hemisphere • Of the 20% in the southern hemisphere region...

  3. Employing lidar to detail vegetation canopy architecture for prediction of aeolian transport

    Science.gov (United States)

    Sankey, Joel B.; Law, Darin J.; Breshears, David D.; Munson, Seth M.; Webb, Robert H.

    2013-01-01

    The diverse and fundamental effects that aeolian processes have on the biosphere and geosphere are commonly generated by horizontal sediment transport at the land surface. However, predicting horizontal sediment transport depends on vegetation architecture, which is difficult to quantify in a rapid but accurate manner. We demonstrate an approach to measure vegetation canopy architecture at high resolution using lidar along a gradient of dryland sites ranging from 2% to 73% woody plant canopy cover. Lidar-derived canopy height, distance (gaps) between vegetation elements (e.g., trunks, limbs, leaves), and the distribution of gaps scaled by vegetation height were correlated with canopy cover and highlight potentially improved horizontal dust flux estimation than with cover alone. Employing lidar to estimate detailed vegetation canopy architecture offers promise for improved predictions of horizontal sediment transport across heterogeneous plant assemblages.

  4. Correction of elevation offsets in multiple co-located lidar datasets

    Science.gov (United States)

    Thompson, David M.; Dalyander, P. Soupy; Long, Joseph W.; Plant, Nathaniel G.

    2017-04-07

    IntroductionTopographic elevation data collected with airborne light detection and ranging (lidar) can be used to analyze short- and long-term changes to beach and dune systems. Analysis of multiple lidar datasets at Dauphin Island, Alabama, revealed systematic, island-wide elevation differences on the order of 10s of centimeters (cm) that were not attributable to real-world change and, therefore, were likely to represent systematic sampling offsets. These offsets vary between the datasets, but appear spatially consistent within a given survey. This report describes a method that was developed to identify and correct offsets between lidar datasets collected over the same site at different times so that true elevation changes over time, associated with sediment accumulation or erosion, can be analyzed.

  5. Specular and diffuse object extraction from a LiDAR derived Digital Surface Model (DSM)

    International Nuclear Information System (INIS)

    Saraf, N M; Hamid, J R A; Kamaruddin, M H

    2014-01-01

    This paper intents to investigate the indifferent behaviour quantitatively of target objects of interest due to specular and diffuse reflectivity based on generated LiDAR DSM of the study site in Ampang, Kuala Lumpur. The LiDAR data to be used was initially checked for its reliability and accuracy. The point cloud LiDAR data was converted to raster to allow grid analysis of the next process of generating the DSM and DTM. Filtering and masking were made removing the features of interest (i.e. building and tree) and other unwanted above surface features. A normalised DSM and object segmentation approach were conducted on the trees and buildings separately. Error assessment and findings attained were highlighted and documented. The result of LiDAR verification certified that the data is reliable and useable. The RMSE obtained is within the tolerance value of horizontal and vertical accuracy (x, y, z) i.e. 0.159 m, 0.211 m 0.091 m respectively. Building extraction inclusive of roof top based on slope and contour analysis undertaken indicate the capability of the approach while single tree extraction through aspect analysis appears to preserve the accuracy of the extraction accordingly. The paper has evaluated the suitable methods of extracting non-ground features and the effective segmentation of the LiDAR data

  6. LIDAR optical rugosity of coral reefs in Biscayne National Park, Florida

    Science.gov (United States)

    Brock, J.C.; Wright, C.W.; Clayton, T.D.; Nayegandhi, A.

    2004-01-01

    The NASA Experimental Advanced Airborne Research Lidar (EAARL), a temporal waveform-resolving, airborne, green wavelength LIDAR (light detection and ranging), is designed to measure the submeter-scale topography of shallow reef substrates. Topographic variability is a prime component of habitat complexity, an ecological factor that both expresses and controls the abundance and distribution of many reef organisms. Following the acquisition of EAARL coverage over both mid-platform patch reefs and shelf-margin bank reefs within Biscayne National Park in August 2002, EAARL-based optical indices of topographic variability were evaluated at 15 patch reef and bank reef sites. Several sites were selected to match reefs previously evaluated in situ along underwater video and belt transects. The analysis used large populations of submarine topographic transects derived from the examination of closely spaced laser spot reflections along LIDAR raster scans. At all 15 sites, each LIDAR transect was evaluated separately to determine optical rugosity (Rotran), and the average elevation difference between adjacent points (Av(??E ap)). Further, the whole-site mean and maximum values of Ro tran and Av(??Eap) for the entire population of transects at each analysis site, along with their standard deviations, were calculated. This study revealed that the greater habitat complexity of inshore patch reefs versus outer bank reefs results in relative differences in topographic complexity that can be discerned in the laser returns. Accordingly, LIDAR sensing of optical rugosity is proposed as a complementary new technique for the rapid assessment of shallow coral reefs. ?? Springer-Verlag 2004.

  7. Progress towards an Autonomous Field Deployable Diode-Laser-Based Differential Absorption Lidar (DIAL for Profiling Water Vapor in the Lower Troposphere

    Directory of Open Access Journals (Sweden)

    Kevin S. Repasky

    2013-11-01

    Full Text Available A laser transmitter has been developed and incorporated into a micro-pulse differential absorption lidar (DIAL for water vapor profiling in the lower troposphere as an important step towards long-term autonomous field operation. The laser transmitter utilizes two distributed Bragg reflector (DBR diode lasers to injection seed a pulsed tapered semiconductor optical amplifier (TSOA, and is capable of producing up to 10 mJ of pulse energy with a 1 ms pulse duration and a 10 kHz pulse repetition frequency. The on-line wavelength of the laser transmitter can operate anywhere along the water vapor absorption feature centered at 828.187 nm (in vacuum depending on the prevailing atmospheric conditions, while the off-line wavelength operates at 828.287 nm. This laser transmitter has been incorporated into a DIAL instrument utilizing a 35.6 cm Schmidt-Cassegrain telescope and fiber coupled avalanche photodiode (APD operating in the photon counting mode. The performance of the DIAL instrument was demonstrated over a ten-day observation period. During this observation period, data from radiosondes were used to retrieve water vapor number density profiles for comparisons with the number density profiles retrieved from the DIAL data.

  8. Lidar-based Research and Innovation at DTU Wind Energy – a Review

    International Nuclear Information System (INIS)

    Mikkelsen, T

    2014-01-01

    As wind turbines during the past decade have increased in size so have the challenges met by the atmospheric boundary-layer meteorologists and the wind energy society to measure and characterize the huge-volume wind fields surpassing and driving them. At the DTU Wind Energy test site ''Østerild'' for huge wind turbines, the hub-height of a recently installed 8 MW Vestas V164 turbine soars 143 meters up above the ground, and its rotor of amazing 164 meters in diameter make the turbine tips flicker 225 meters into the sky. Following the revolution in photonics-based telecommunication at the turn of the Millennium new fibre-based wind lidar technologies emerged and DTU Wind Energy, at that time embedded within Rise National Laboratory, began in collaboration with researchers from wind lidar companies to measure remote sensed wind profiles and turbulence structures within the atmospheric boundary layer with the emerging, at that time new, all-fibre-based 1.55 μ coherent detection wind lidars. Today, ten years later, DTU Wind Energy routinely deploys ground-based vertical profilers instead of met masts for high-precision measurements of mean wind profiles and turbulence profiles. At the departments test site ''Høvsøre'' DTU Wind Energy also routinely calibrate and accredit wind lidar manufactures wind lidars. Meanwhile however, new methodologies for power curve assessment based on ground-based and nacelle based lidars have also emerged. For improving the turbines power curve assessments and for advancing their control with feed-forward wind measurements experience has also been gained with wind lidars installed on turbine nacelles and integrated into the turbines rotating spinners. A new mobile research infrastructure WindScanner.dk has also emerged at DTU Wind Energy. Wind and turbulence fields are today scanned from sets of three simultaneously in space and time synchronized scanning lidars. One set consists of three fast

  9. AUTOMATED RECONSTRUCTION OF WALLS FROM AIRBORNE LIDAR DATA FOR COMPLETE 3D BUILDING MODELLING

    Directory of Open Access Journals (Sweden)

    Y. He

    2012-07-01

    Full Text Available Automated 3D building model generation continues to attract research interests in photogrammetry and computer vision. Airborne Light Detection and Ranging (LIDAR data with increasing point density and accuracy has been recognized as a valuable source for automated 3D building reconstruction. While considerable achievements have been made in roof extraction, limited research has been carried out in modelling and reconstruction of walls, which constitute important components of a full building model. Low point density and irregular point distribution of LIDAR observations on vertical walls render this task complex. This paper develops a novel approach for wall reconstruction from airborne LIDAR data. The developed method commences with point cloud segmentation using a region growing approach. Seed points for planar segments are selected through principle component analysis, and points in the neighbourhood are collected and examined to form planar segments. Afterwards, segment-based classification is performed to identify roofs, walls and planar ground surfaces. For walls with sparse LIDAR observations, a search is conducted in the neighbourhood of each individual roof segment to collect wall points, and the walls are then reconstructed using geometrical and topological constraints. Finally, walls which were not illuminated by the LIDAR sensor are determined via both reconstructed roof data and neighbouring walls. This leads to the generation of topologically consistent and geometrically accurate and complete 3D building models. Experiments have been conducted in two test sites in the Netherlands and Australia to evaluate the performance of the proposed method. Results show that planar segments can be reliably extracted in the two reported test sites, which have different point density, and the building walls can be correctly reconstructed if the walls are illuminated by the LIDAR sensor.

  10. Frequency Stepped Pulse Train Modulated Wind Sensing Lidar

    DEFF Research Database (Denmark)

    Olesen, Anders Sig; Pedersen, Anders Tegtmeier; Rottwitt, Karsten

    2011-01-01

    of frequency shifts corresponding to a specific distance. The spatial resolution depends on the repetition rate of the pulses in the pulse train. Directional wind measurements are shown and compared to a CW lidar measurement. The carrier to noise ratio of the FSPT lidar compared to a CW lidar is discussed......In this paper a wind sensing lidar utilizing a Frequency Stepped Pulse Train (FSPT) is demonstrated. One of the advantages in the FSTP lidar is that it enables direct measurement of wind speed as a function of distance from the lidar. Theoretically the FSPT lidar continuously produces measurements...... as is the case with a CW lidar, but at the same time with a spatial resolution, and without the range ambiguity originating from e.g. clouds. The FSPT lidar utilizes a frequency sweeping source for generation of the FSPT. The source generates a pulse train where each pulse has an optical carrier frequency...

  11. 2010 Northwestern Hawaiian Islands Lidar - Midway Atoll

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. Geological Survey (USGS) contracted with Hawaii-based Aerial Surveying, Inc. to collect lidar-derived elevation data over the low-lying areas within the...

  12. 2010 Northwestern Hawaiian Islands Lidar - Laysan Island

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. Geological Survey (USGS) contracted with Hawaii-based Aerial Surveying, Inc. to collect lidar-derived elevation data over the low-lying areas within the...

  13. 2012 OLC Lidar: West Metro, Oregon

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — WSI has collected Light Detection and Ranging (LiDAR) data of the Oregon West Metro Study Area for the Oregon Department of Geology and Mineral Industries (DOGAMI)....

  14. 2012 OLC Lidar DEM: West Metro, Oregon

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — WSI has collected Light Detection and Ranging (LiDAR) data of the Oregon West Metro Study Area for the Oregon Department of Geology and Mineral Industries (DOGAMI)....

  15. 2013 South Carolina DNR Lidar: Greenville County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Group provided high accuracy, calibrated multiple return LiDAR for roughly 1,510 square miles covering both Greenville and Spartanburg counties, South...

  16. 2006 NOAA Bathymetric Lidar: Puerto Rico (Southwest)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set (Project Number OPR-I305-KRL-06) depicts depth values (mean 5 meter gridded) collected using LiDAR (Light Detection & Ranging) from the shoreline...

  17. USGS Atchafalaya 2 LiDAR

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Light Detection and Ranging (LiDAR) dataset is a survey of the Atchafalaya Basin project area. The entire survey area for Atchafalaya encompasses approximately...

  18. 2004 Harrison County, Mississippi Lidar Mapping

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This metadata record describes the topographic mapping of Harrison County, Mississippi in March of 2004. Products generated include lidar point clouds in .LAS format...

  19. 2015 Cook & Tift County (GA) Lidar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: NOAA OCM Tift and Cook Counties GA Lidar Data Acquisition and Processing Production Task NOAA Contract No. EA133C-11-CQ-0010 Woolpert Order No. 75271...

  20. 2010 ARRA Lidar: Golden Gate (CA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Golden Gate LiDAR Project is a cooperative project sponsored by the US Geological Survey (USGS) and San Francisco State University (SFSU) that has resulted in...

  1. 2012 USGS Lidar: Brooks Camp (AK)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. Geological Survey (USGS) had a requirement for high resolution Lidar needed for mapping the Brooks Camp region of Katmai National Park in Alaska....

  2. 2005 Oahu/Maui Lidar Mapping Project

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — LIDAR data is remotely sensed high-resolution elevation data collected by an airborne collection platform. Using a combination of laser rangefinding, GPS positioning...

  3. 2004 USGS Lidar: San Francisco Bay (CA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Lidar (Light detection and ranging) discrete-return point cloud data are available in the American Society for Photogrammetry and Remote Sensing (ASPRS) LAS format....

  4. 2010 ARRA Lidar: Eleven County Virginia

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Terrapoint and LMSI collected LiDAR for over 2,572 square miles in Northumberland, Lancaster, Middlesex, King and Queen, Matthews, Gloucester, James City,...

  5. 2012 South Carolina DNR Lidar: Edgefield County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Towill Inc. collected LiDAR for over 3,300 square miles in Calhoun, Aiken, Barnwell, Edgefield, McCormick, and Abbeville counties in South Carolina. This metadata...

  6. 2007 Sumpter Powder River Mine Lidar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. (WS) collected Light Detection and Ranging (LiDAR) data for the USDA Forest Service on September 17, 2007. The project covers an 8-mile...

  7. 2009 - 2011 OLC Lidar DEM: Deschutes (OR)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. collected Light Detection and Ranging (LiDAR) data of the Deschutes Study Area for the Oregon Department of Geology and Mineral Industries...

  8. 2008 USGS New Jersey Lidar: Somerset County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data support the general geospatial needs of the USGS and other federal agencies. LiDAR data is remotely sensed high-resolution elevation data collected by an...

  9. 2016 USGS Lidar: Maine QL2

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Product: This lidar data set includes classified LAS files, breaklines, digital elevation models (DEMs), intensity imagery, and contours. Geographic Extent: Four...

  10. 2013 South Carolina DNR Lidar: Beaufort County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — LMSI provided high accuracy, calibrated multiple return LiDAR for roughly 785 square miles covering Beaufort County, South Carolina. The nominal point spacing for...

  11. 2004 FEMA Lidar: Blackstone (MA & RI)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The LIDAR-derived data was collected in the Blackstone River area. This data supports the Federal Emergency Management Agency's specifications for mapping...

  12. Nonlinear filtering for LIDAR signal processing

    Directory of Open Access Journals (Sweden)

    D. G. Lainiotis

    1996-01-01

    Full Text Available LIDAR (Laser Integrated Radar is an engineering problem of great practical importance in environmental monitoring sciences. Signal processing for LIDAR applications involves highly nonlinear models and consequently nonlinear filtering. Optimal nonlinear filters, however, are practically unrealizable. In this paper, the Lainiotis's multi-model partitioning methodology and the related approximate but effective nonlinear filtering algorithms are reviewed and applied to LIDAR signal processing. Extensive simulation and performance evaluation of the multi-model partitioning approach and its application to LIDAR signal processing shows that the nonlinear partitioning methods are very effective and significantly superior to the nonlinear extended Kalman filter (EKF, which has been the standard nonlinear filter in past engineering applications.

  13. 2011 USGS Lidar: Orange County (CA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — LiDAR (Light Detection and Ranging) discrete-return point cloud data are available in the American Society for Photogrammetry and Remote Sensing (ASPRS) LAS format....

  14. 2012 South Carolina DNR Lidar: Calhoun County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Towill Inc. collected LiDAR for over 3,300 square miles in Calhoun, Aiken, Barnwell, Edgefield, McCormick, and Abbeville counties in South Carolina. This metadata...

  15. 2011 FEMA Lidar: Southern Virginia Cities

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Dewberry collected LiDAR for ~3,341 square miles in various Virginia Counties, a part of Worcester County, and Hooper's Island. The acquisition was performed by...

  16. 2013 South Carolina DNR Lidar: Spartanburg County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Group provided high accuracy, calibrated multiple return LiDAR for roughly 1,510 square miles covering both Greenville and Spartanburg counties, South...

  17. 2010 USGS Lidar: Salton Sea (CA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The USGS Salton Sea project encompasses a 5-kilometer buffer around the Salton Sea, California. Dewberry classified LiDAR for a project boundary that touches 623...

  18. 2014 USACE NCMP Topobathy Lidar DEM: Oregon

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These Digital Elevation Model (DEM) files contain rasterized topobathy lidar elevations at a 1 m grid size, generated from data collected by the Coastal Zone Mapping...

  19. 2010 South Carolina DNR Lidar: Sumter County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Provide high density LiDAR elevation data map of Sumter County, SC. Provide Bare Earth DEM (vegetation removal) of Sumter County, SC.

  20. 2010 South Carolina DNR Lidar: Richland County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Provide high density LiDAR elevation data map of Richland County, SC. Provide Bare Earth DEM (vegetation removal) of Richland County, SC.

  1. 2015 City of Portland, Maine, Lidar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — 2015 City of Portland Maine Lidar Data Acquisition and Processing Woolpert Order No. 75564 Contractor: Woolpert, Inc. This task is for a high resolution data set of...

  2. 2016 Martin County QL2 Lidar (FL)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Martin County FL QL2 Lidar Acquisition and Processing Production Task Task Order No. G14PS00574 Woolpert Order No. 76001 Contractor: Woolpert, Inc. This task is for...

  3. VT Data - Lidar 1ft Contours

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) This metadata applies to contours derived from Quality Level 2 (QL2) Lidar 'collections' with a resolution (RESCLASS) of 0.7m. For an overview of...

  4. 2009 - 2011 OLC Lidar: Deschutes (OR)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. collected Light Detection and Ranging (LiDAR) data of the Deschutes Study Area for the Oregon Department of Geology and Mineral Industries...

  5. 2005 NCFMP Lidar: NC Statewide Phase 3

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne LIDAR terrain mapping data acquired March through April 2005. These data sets may represent a single geographic tile of a larger, county/sub-county data...

  6. 2015 NOAA Lidar: Pelekane Watershed (HI)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This metadata describes the Digital Elevation Model (DEM) 1 meter products derived from the airborne LiDAR data collected in August of 2015 for the Pelekane...

  7. 2006 FEMA Lidar: Rhode Island Coastline

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — LIDAR data is remotely sensed high-resolution elevation data collected by an airborne collection platform. By positioning laser range finding with the use of 1...

  8. 2010 South Carolina DNR Lidar: Kershaw County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Provide high density LiDAR elevation data map of Kershaw County, SC. Provide Bare Earth DEM (vegetation removal) of Kershaw County, SC.

  9. 2010 Northwestern Hawaiian Islands Lidar - Kure Atoll

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. Geological Survey (USGS) contracted with Hawaii-based Aerial Surveying, Inc. to collect lidar-derived elevation data over the low-lying areas within the...

  10. 2010 Northwestern Hawaiian Islands Lidar - Lisianki Island

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. Geological Survey (USGS) contracted with Hawaii-based Aerial Surveying, Inc. to collect lidar-derived elevation data over the low-lying areas within the...

  11. 2003 NCFMP Lidar: NC Statewide Phase 2

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne LIDAR terrain mapping data acquired January through March 2003. Point data (XYZ) in ASCII format. Horizontal datum NAD83(1995) North Carolina State Plane...

  12. The influence of water/air cooling on collateral tissue damage using a diode laser with an innovative pulse design (micropulsed mode)-an in vitro study.

    Science.gov (United States)

    Beer, F; Körpert, W; Buchmair, A G; Passow, H; Meinl, A; Heimel, P; Moritz, A

    2013-05-01

    Since the diode laser is a good compromise for the daily use in dental offices, finding usage in numerous dental indications (e.g., surgery, periodontics, and endodontics), the minimization of the collateral damage in laser surgery is important to improve the therapeutical outcome. The aim of this study was to investigate the effect of water/air cooling on the collateral thermal soft tissue damage of 980-nm diode laser incisions. A total of 36 mechanically executed laser cuts in pork liver were made with a 980-nm diode laser in micropulsed mode with three different settings of water/air cooling and examined by histological assessment to determine the area and size of carbonization, necrosis, and reversible tissue damage as well as incision depth and width. In our study, clearly the incision depth increased significantly under water/air cooling (270.9 versus 502.3 μm-test group 3) without significant changes of incision width. In test group 2, the total area of damage was significantly smaller than in the control group (in this group, the incision depth increases by 65 %). In test group 3, the total area of damage was significantly higher (incision depth increased by 85 %), but the bigger part of it represented a reversible tissue alteration leaving the amount of irreversible damage almost the same as in the control group. This first pilot study clearly shows that water/air cooling in vitro has an effect on collateral tissue damage. Further studies will have to verify, if the reduced collateral damage we have proved in this study can lead to accelerated wound healing. Reduction of collateral thermal damage after diode laser incisions is clinically relevant for promoted wound healing.

  13. Lidar instruments for ESA Earth observation missions

    Science.gov (United States)

    Hélière, Arnaud; Armandillo, Errico; Durand, Yannig; Culoma, Alain; Meynart, Roland

    2017-11-01

    The idea of deploying a lidar system on an Earthorbiting satellite stems from the need for continuously providing profiles of our atmospheric structure with high accuracy and resolution and global coverage. Interest in this information for climatology, meteorology and the atmospheric sciences in general is huge. Areas of application range from the determination of global warming and greenhouse effects, to monitoring the transport and accumulation of pollutants in the different atmospheric regions (such as the recent fires in Southeast Asia), to the assessment of the largely unknown microphysical properties and the structural dynamics of the atmosphere itself. Spaceborne lidar systems have been the subject of extensive investigations by the European Space Agency since mid 1970's, resulting in mission and instrument concepts, such as ATLID, the cloud backscatter lidar payload of the EarthCARE mission, ALADIN, the Doppler wind lidar of the Atmospheric Dynamics Mission (ADM) and more recently a water vapour Differential Absorption Lidar considered for the WALES mission. These studies have shown the basic scientific and technical feasibility of spaceborne lidars, but they have also demonstrated their complexity from the instrument viewpoint. As a result, the Agency undertook technology development in order to strengthen the instrument maturity. This is the case for ATLID, which benefited from a decade of technology development and supporting studies and is now studied in the frame of the EarthCARE mission. ALADIN, a Direct Detection Doppler Wind Lidar operating in the Ultra -Violet, will be the 1st European lidar to fly in 2007 as payload of the Earth Explorer Core Mission ADM. WALES currently studied at the level of a phase A, is based upon a lidar operating at 4 wavelengths in near infrared and aims to profile the water vapour in the lower part of the atmosphere with high accuracy and low bias. Lastly, the European Space Agency is extending the lidar instrument field

  14. Evaluating UAV and LiDAR Retrieval of Snow Depth in a Coniferous Forest in Arizona

    Science.gov (United States)

    Van Leeuwen, W. J. D.; Broxton, P.; Biederman, J. A.

    2017-12-01

    Remote sensing of snow depth and cover in forested environments is challenging. Trees interfere with the remote sensing of snowpack below the canopy and cause large variations in the spatial distribution of the snowpack itself (e.g. between below canopy environments to shaded gaps to open clearings). The distribution of trees and topographic variation make it challenging to monitor the snowpack with in-situ observations. Airborne LiDAR has improved our ability to monitor snowpack over large areas in montane and forested environments because of its high sampling rate and ability to penetrate the canopy. However, these LiDAR flights can be too expensive and time-consuming to process, making it hard to use them for real-time snow monitoring. In this research, we evaluate Structure from Motion (SfM) as an alternative to Airborne LiDAR to generate high-resolution snow depth data in forested environments. This past winter, we conducted a snow field campaign over Arizona's Mogollon Rim where we acquired aerial LiDAR, multi-angle aerial photography from a UAV, and extensive field observations of snow depth at two sites. LiDAR and SFM derived snow depth maps were generated by comparing "snow-on" and "snow-off" LiDAR and SfM data. The SfM- and LiDAR-generated snow depth maps were similar at a site with fewer trees, though there were more discrepancies at a site with more trees. Both compared reasonably well with the field observations at the sparser forested site, with poorer agreement at the denser forested site. Finally, although the SfM produced point clouds with much higher point densities than the aerial LiDAR, the SfM was not able to produce meaningful snow depth estimates directly underneath trees and had trouble in areas with deep shadows. Based on these findings, we are optimizing our UAV data acquisition strategies for this upcoming field season. We are using these data, along with high-resolution hydrological modeling, to gain a better understanding of how

  15. Effect of multiple scattering on lidar measurements

    International Nuclear Information System (INIS)

    Cohen, A.

    1977-01-01

    The lidar equation in its standard form involves the assumption that the scattered irradiance reaching the lidar receiver has been only singly scattered. However, in the cases of scattering from clouds and thick aerosol layers, it is shown that multiple scattering cannot be neglected. An experimental method for the detection of multiple scattering by depolarization measurement techniques is discussed. One method of theoretical calculations of double-scattering is presented and discussed

  16. Foredune Classification and Storm Response: Automated Analysis of Terrestrial Lidar DEMs

    Science.gov (United States)

    2015-06-15

    since Hurricane Sandy. 041 20/3/2015 4 Figure 1. A. The study site in Duck , NC showing the alongshore coordinates of the local coordinate...waves on March 10: Hs = 4.8 m at 16 sec Coastal Lidar and Radar Imaging System (CLARIS) Nor’easter Storm Conditions Study Site: Duck , NC...Engineer Research and Development Center, Coastal & Hydraulics Laboratory, Coastal Observation & Analysis Branch, 1261 Duck Rd, Duck , NC 27949, USA

  17. Heterodyne lidar for chemical sensing

    International Nuclear Information System (INIS)

    Oldenborg, Richard C.; Tiee, Joe J.; Shimada, Tsutomu; Wilson, Carl W.; Remelius, Dennis K.; Fox, Jay; Swim, Cynthia

    2004-01-01

    The overall objective is to assess the detection performance of LWIR (long wavelength infrared) coherent Lidar systems that potentially possess enhanced effluent detection capabilities. Previous work conducted by Los Alamos has demonstrated that infrared DIfferential Absorption Lidar (DIAL) is capable of detecting chemicals in plumes from long standoff ranges. Our DIAL approach relied on the reflectivity of topographical targets to provide a strong return signal. With the inherent advantage of applying heterodyne transceivers to approach single-photon detection in LWIR, it is projected that marked improvements in detection range or in spatial coverage can be attained. In some cases, the added photon detection sensitivity could be utilized for sensing 'soft targets', such as atmospheric and threat aerosols where return signal strength is drastically reduced, as opposed to topographical targets. This would allow range resolved measurements and could lead to the mitigation of the limiting source of noise due to spectral/spatial/temporal variability of the ground scene. The ability to distinguish normal variations in the background from true chemical signatures is crucial to the further development of sensitive remote chemical sensing technologies. One main difficulty in demonstrating coherent DIAL detection is the development of suitable heterodyne transceivers that can achieve rapid multi-wavelength tuning required for obtaining spectral signature information. LANL has recently devised a novel multi-wavelength heterodyne transceiver concept that addresses this issue. A 5-KHz prototype coherent CO 2 transceiver has been constructed and is being now used to help address important issues in remote CBW agent standoff detection. Laboratory measurements of signal-to-noise ratio (SNR) will be reported. Since the heterodyne detection scheme fundamentally has poor shot-to-shot signal statistics, in order to achieve sensitive detection limits, favorable averaging statistics

  18. Lidar-based biomass assessment for the Yukon River Basin

    Science.gov (United States)

    Peterson, B.; Wylie, B. K.; Stoker, J.; Nossov, D.

    2010-12-01

    lidar data set and are expected to result in improved biomass products for the YRB as they have been shown to be highly predictive of biomass in other biomes. The results of this project represent the first step in a larger effort to collect lidar and field data for various study sites across the YRB for biomass estimations to train large-scale mapping efforts using Landsat imagery and radar data. Bond-Lamberty, B., C. Wang, and S.T. Gower. 2002. Aboveground and belowground biomass and sapwood area allometric equations for six boreal tree species of northern Manitoba. Canadian Journal of Forest Research 32: 1441-1450. Mack, M., K. Treseder, K. Manies, J. Harden, E. Schuur, J. Vogel, J. Randerson, and F.S. Chapin III. 2008. Recovery of Aboveground Plant Biomass and Productivity After Fire in Mesic and Dry Black Spruce Forests of Interior Alaska, Ecosystems v.11:209-225. Yarie, J., E. Kane, and M. Mack. 2007. Aboveground Biomass Equations for the Trees of Interior Alaska. AFES Bulletin 115.

  19. Utilizing LiDAR Datasets From Experimental Watersheds to Advance Ecohydrological Understanding in Seasonally Snow-Covered Forests

    Science.gov (United States)

    Harpold, A. A.; Broxton, P. D.; Guo, Q.; Barlage, M. J.; Gochis, D. J.

    2014-12-01

    The Western U.S. is strongly reliant on snowmelt from forested areas for ecosystem services and downstream populations. The ability to manage water resources from snow-covered forests faces major challenges from drought, disturbance, and regional changes in climate. An exciting avenue for improving ecohydrological process understanding is Light Detection and Ranging (LiDAR) because the technology simultaneously observes topography, forest properties, and snow/ice at high-resolution (100 km2). The availability and quality of LiDAR datasets is increasing rapidly, however they remain under-utilized for process-based ecohydrology investigations. This presentation will illustrate how LiDAR datasets from the Critical Zone Observatory (CZO) network have been applied to advance ecohydrological understanding through direct empirical analysis, as well as model parameterization and verification. Direct analysis of the datasets has proved fruitful for pre- and post-disturbance snow distribution estimates and interpreting in-situ snow depth measurements across sites. In addition, we illustrate the potential value of LiDAR to parameterize and verify of physical models with two examples. First, we use LiDAR to parameterize a land surface model, Noah multi-parameterization (Noah-MP), to investigate the sensitivity of modeled water and energy fluxes to high-resolution forest information. Second, we present a Snow Physics and Laser Mapping (SnowPALM) model that is parameterized with LiDAR information at its native 1-m scale. Both modeling studies demonstrate the value of LiDAR for representing processes with greater fidelity. More importantly, the increased model fidelity led to different estimates of water and energy fluxes at larger, watershed scales. Creating a network of experimental watersheds with LiDAR datasets offers the potential to test theories and models in previously unexplored ways.

  20. Model of the Correlation between Lidar Systems and Wind Turbines for Lidar-Assisted Control

    DEFF Research Database (Denmark)

    Schlipf, David; Cheng, Po Wen; Mann, Jakob

    2013-01-01

    - or spinner-based lidar system. If on the one hand, the assumed correlation is overestimated, then the uncorrelated frequencies of the preview will cause unnecessary control action, inducing undesired loads. On the other hand, the benefits of the lidar-assisted controller will not be fully exhausted......, if correlated frequencies are filtered out. To avoid these miscalculations, this work presents a method to model the correlation between lidar systems and wind turbines using Kaimal wind spectra. The derived model accounts for different measurement configurations and spatial averaging of the lidar system......Investigations of lidar-assisted control to optimize the energy yield and to reduce loads of wind turbines have increased significantly in recent years. For this kind of control, it is crucial to know the correlation between the rotor effective wind speed and the wind preview provided by a nacelle...

  1. Geospatial revolution and remote sensing LiDAR in Mesoamerican archaeology

    Science.gov (United States)

    Chase, Arlen F.; Fisher, Christopher T.; Leisz, Stephen J.; Weishampel, John F.

    2012-01-01

    The application of light detection and ranging (LiDAR), a laser-based remote-sensing technology that is capable of penetrating overlying vegetation and forest canopies, is generating a fundamental shift in Mesoamerican archaeology and has the potential to transform research in forested areas world-wide. Much as radiocarbon dating that half a century ago moved archaeology forward by grounding archaeological remains in time, LiDAR is proving to be a catalyst for an improved spatial understanding of the past. With LiDAR, ancient societies can be contextualized within a fully defined landscape. Interpretations about the scale and organization of densely forested sites no longer are constrained by sample size, as they were when mapping required laborious on-ground survey. The ability to articulate ancient landscapes fully permits a better understanding of the complexity of ancient Mesoamerican urbanism and also aids in modern conservation efforts. The importance of this geospatial innovation is demonstrated with newly acquired LiDAR data from the archaeological sites of Caracol, Cayo, Belize and Angamuco, Michoacán, Mexico. These data illustrate the potential of technology to act as a catalytic enabler of rapid transformational change in archaeological research and interpretation and also underscore the value of on-the-ground archaeological investigation in validating and contextualizing results. PMID:22802623

  2. Geospatial revolution and remote sensing LiDAR in Mesoamerican archaeology.

    Science.gov (United States)

    Chase, Arlen F; Chase, Diane Z; Fisher, Christopher T; Leisz, Stephen J; Weishampel, John F

    2012-08-07

    The application of light detection and ranging (LiDAR), a laser-based remote-sensing technology that is capable of penetrating overlying vegetation and forest canopies, is generating a fundamental shift in Mesoamerican archaeology and has the potential to transform research in forested areas world-wide. Much as radiocarbon dating that half a century ago moved archaeology forward by grounding archaeological remains in time, LiDAR is proving to be a catalyst for an improved spatial understanding of the past. With LiDAR, ancient societies can be contextualized within a fully defined landscape. Interpretations about the scale and organization of densely forested sites no longer are constrained by sample size, as they were when mapping required laborious on-ground survey. The ability to articulate ancient landscapes fully permits a better understanding of the complexity of ancient Mesoamerican urbanism and also aids in modern conservation efforts. The importance of this geospatial innovation is demonstrated with newly acquired LiDAR data from the archaeological sites of Caracol, Cayo, Belize and Angamuco, Michoacán, Mexico. These data illustrate the potential of technology to act as a catalytic enabler of rapid transformational change in archaeological research and interpretation and also underscore the value of on-the-ground archaeological investigation in validating and contextualizing results.

  3. Vertical profiles of atmospheric fluorescent aerosols observed by a mutil-channel lidar spectrometer system

    Science.gov (United States)

    Huang, Z.; Huang, J.; Zhou, T.; Sugimoto, N.; Bi, J.

    2015-12-01

    Zhongwei Huang1*, Jianping Huang1, Tian Zhou1, Nobuo Sugimoto2, Jianrong Bi1 and Jinsen Shi11Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou, China. 2Atmospheric Environment Division, National Institutes for Environmental Studies, Tsukuba, Japan Email: huangzhongwei@lzu.edu.cn Abstract Atmospheric aerosols have a significant impact on regional and globe climate. The challenge in quantifying aerosol direct radiative forcing and aerosol-cloud interactions arises from large spatial and temporal heterogeneity of aerosol concentrations, compositions, sizes, shape and optical properties (IPCC, 2007). Lidar offers some remarkable advantages for determining the vertical structure of atmospheric aerosols and their related optical properties. To investigate the characterization of atmospheric aerosols (especially bioaerosols) with high spatial and temporal resolution, we developed a Raman/fluorescence/polarization lidar system employed a multi-channel spectrometer, with capabilities of providing measurements of Raman scattering and laser-induced fluorescence excitation at 355 nm from atmospheric aerosols. Meanwhile, the lidar system operated polarization measurements both at 355nm and 532nm wavelengths, aiming to obtain more information of aerosols. It employs a high power pulsed laser and a received telescope with 350mm diameter. The receiver could simultaneously detect a wide fluorescent spectrum about 178 nm with spectral resolution 5.7 nm, mainly including an F/3.7 Crossed Czerny-Turner spectrograph, a grating (1200 gr/mm) and a PMT array with 32 photocathode elements. Vertical structure of fluorescent aerosols in the atmosphere was observed by the developed lidar system at four sites across northwest China, during 2014 spring field observation that conducted by Lanzhou University. It has been proved that the developed lidar could detect the fluorescent aerosols with high temporal and

  4. 2013-2014 USGS Lidar: Olympic Peninsula (WA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: USGS Olympic Peninsula Washington LIDAR LiDAR Data Acquisition and Processing Production Task USGS Contract No. G10PC00057 Task Order No. G13PD00849...

  5. 2015 OLC FEMA Lidar DEM: Snake River, ID

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Quantum Spatial has collected Light Detection and Ranging (LiDAR) data for the Oregon LiDAR Consortium (OLC) Snake River FEMA study area. This study area is located...

  6. GRIP DOPPLER AEROSOL WIND LIDAR (DAWN) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GRIP Doppler Aerosol WiNd Lidar (DAWN) Dataset was collected by the Doppler Aerosol WiNd (DAWN), a pulsed lidar, which operated aboard a NASA DC-8 aircraft...

  7. NAMMA LIDAR ATMOSPHERIC SENSING EXPERIMENT (LASE) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The NAMMA Lidar Atmospheric Sensing Experiment (LASE) dataset used the LASE system using the Differential Absorption Lidar (DIAL) system was operated during the NASA...

  8. 2009 - 2011 CA Coastal Conservancy Coastal Lidar Project

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Light Detection and Ranging (LiDAR) data is remotely sensed high-resolution elevation data collected by an airborne collection platform. This LiDAR dataset is a...

  9. 2014 USGS CMGP Lidar: Post Sandy (Long Island, NY)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: Long Island New York Sandy LIDAR lidar Data Acquisition and Processing Production Task USGS Contract No. G10PC00057 Task Order No. G14PD00296 Woolpert...

  10. Multi-wavelength Ocean Profiling and Atmospheric Lidar

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to build and demonstrate the world's first multi-wavelength ocean-profiling high spectral resolution lidar (HSRL). The lidar will provide profiles of...

  11. Occurrence and characteristics of mutual interference between LIDAR scanners

    Science.gov (United States)

    Kim, Gunzung; Eom, Jeongsook; Park, Seonghyeon; Park, Yongwan

    2015-05-01

    The LIDAR scanner is at the heart of object detection of the self-driving car. Mutual interference between LIDAR scanners has not been regarded as a problem because the percentage of vehicles equipped with LIDAR scanners was very rare. With the growing number of autonomous vehicle equipped with LIDAR scanner operated close to each other at the same time, the LIDAR scanner may receive laser pulses from other LIDAR scanners. In this paper, three types of experiments and their results are shown, according to the arrangement of two LIDAR scanners. We will show the probability that any LIDAR scanner will interfere mutually by considering spatial and temporal overlaps. It will present some typical mutual interference scenario and report an analysis of the interference mechanism.

  12. 2006 FEMA New Jersey Flood Mitigation Lidar: Highlands Area

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Light Detection and Ranging (LiDAR) data is remotely sensed high-resolution elevation data collected by an airborne collection platform. LiDAR was flown for...

  13. 2012 NOAA Fisheries Topographic Lidar: Bridge Creek, Oregon

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is an LAZ (compressed LAS) format file containing LIDAR point cloud data. This data set is an LAZ (compressed LAS) format file containing LIDAR point...

  14. 2010 USGS Lidar: Southeastern Michigan (Hillsdale, Jackson, Lenawee Counties)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: Lake Erie LiDAR Priority Area 1 LiDAR Data Acquisition and Processing Production Task- Jackson, Hillsdale, and Lenawee Counties USGS Contract No....

  15. 2012 NRCS-USGS Tupelo, MS Lidar Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — LiDAR data is a remotely sensed high resolution elevation data collected by an airborne platform. The LiDAR sensor uses a combination of laser range finding, GPS...

  16. 2008 Florida Division of Emergency Management Lidar: Middle Suwannee River

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — LiDAR Survey for the Suwannee River Water Management District (SRWMD), Florida. The LiDAR aerial acquisition was conducted in January of 2008, and the breaklines and...

  17. 2015 Oregon Department Forestry Lidar DEM: Northwest OR

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — GeoTerra, Inc. was selected by Oregon Department of Forestry to provide Lidar remote sensing data including LAZ files of the classified Lidar points and surface...

  18. Wind turbine wake visualization and characteristics analysis by Doppler lidar.

    Science.gov (United States)

    Wu, Songhua; Liu, Bingyi; Liu, Jintao; Zhai, Xiaochun; Feng, Changzhong; Wang, Guining; Zhang, Hongwei; Yin, Jiaping; Wang, Xitao; Li, Rongzhong; Gallacher, Daniel

    2016-05-16

    Wind power generation is growing fast as one of the most promising renewable energy sources that can serve as an alternative to fossil fuel-generated electricity. When the wind turbine generator (WTG) extracts power from the wind, the wake evolves and leads to a considerable reduction in the efficiency of the actual power generation. Furthermore, the wake effect can lead to the increase of turbulence induced fatigue loads that reduce the life time of WTGs. In this work, a pulsed coherent Doppler lidar (PCDL) has been developed and deployed to visualize wind turbine wakes and to characterize the geometry and dynamics of wakes. As compared with the commercial off-the-shelf coherent lidars, the PCDL in this work has higher updating rate of 4 Hz and variable physical spatial resolution from 15 to 60 m, which improves its capability to observation the instantaneous turbulent wind field. The wind speed estimation method from the arc scan technique was evaluated in comparison with wind mast measurements. Field experiments were performed to study the turbulent wind field in the vicinity of operating WTGs in the onshore and offshore wind parks from 2013 to 2015. Techniques based on a single and a dual Doppler lidar were employed for elucidating main features of turbine wakes, including wind velocity deficit, wake dimension, velocity profile, 2D wind vector with resolution of 10 m, turbulence dissipation rate and turbulence intensity under different conditions of surface roughness. The paper shows that the PCDL is a practical tool for wind energy research and will provide a significant basis for wind farm site selection, design and optimization.

  19. Sporadic and Thermospheric Enhanced Sodium Layers Observed by a Lidar Chain over China

    Science.gov (United States)

    Xue, X.

    2013-12-01

    We report the statistical features of sporadic sodium layers (SSLs) and the thermospheric enhanced sodium layers (TeSLs) observed by a lidar chain located at Beijing (40.2N,116.2E), Hefei (31.8N, 117.3E), Wuhan (30.5N, 114.4E), and Haikou (19.5N, 109.1E). The average SSL occurrence rate was approximately 46.0, 12.3, 13.8, and 15.0 hr per SSL at Beijing, Hefei, Wuhan, and Haikou, respectively. However, the TeSLs occurred relatively infrequently and were more likely to appear at low and high latitudinal sites. Both the SSLs and TeSLs at four lidar sites showed evident summer enhancements and correlated well with Es (foEs>4MHz). The co-observations of SSLs at three lidar site pairs, i.e., Hefei -- Beijing, Hefei -- Wuhan and Hefei -- Beijing, indicated that a large-scale SSL extended horizontally for at least a few hundred kilometers and exhibited a tidal-induced modulation. Moreover, the SSLs were better correlated for the Hefei -- Wuhan and Hefei -- Haikou pairs than the Hefei -- Beijing pair, which suggested a difference in the dynamical/chemical process in mesosphere and lower thermosphere (MLT) between the Beijing site and the other sites.

  20. 2012 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Quinault River Watershed, Washington (Delivery 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. (WSI) collected Light Detection and Ranging (LiDAR) data on the Quinault watershed survey area for the Puget Sound LiDAR Consortium. This...

  1. 2014 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Cedar River Watershed (Delivery 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In September 2013, WSI, a Quantum Spatial company (QSI), was contracted by the Puget Sound LiDAR Consortium (PSLC) to collect Light Detection and Ranging (LiDAR)...

  2. 2014 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Cedar River Watershed (Delivery 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In September 2013, WSI, a Quantum Spatial company (QSI), was contracted by the Puget Sound LiDAR Consortium (PSLC) to collect Light Detection and Ranging (LiDAR)...

  3. Applications of KHZ-CW Lidar in Ecological Entomology

    Science.gov (United States)

    Malmqvist, Elin; Brydegaard, Mikkel

    2016-06-01

    The benefits of kHz lidar in ecological entomology are explained. Results from kHz-measurements on insects, carried out with a CW-lidar system, employing the Scheimpflug principle to obtain range resolution, are presented. A method to extract insect events and analyze the large amount of lidar data is also described.

  4. Augmented Reality Based Doppler Lidar Data Visualization: Promises and Challenges

    Directory of Open Access Journals (Sweden)

    Cherukuru N. W.

    2016-01-01

    As a proof of concept, we used the lidar data from a recent field campaign and developed a smartphone application to view the lidar scan in augmented reality. In this paper, we give a brief methodology of this feasibility study, present the challenges and promises of using AR technology in conjunction with Doppler wind lidars.

  5. Charactering lidar optical subsystem using four quadrants method

    Science.gov (United States)

    Tian, Xiaomin; Liu, Dong; Xu, Jiwei; Wang, Zhenzhu; Wang, Bangxin; Wu, Decheng; Zhong, Zhiqing; Xie, Chenbo; Wang, Yingjian

    2018-02-01

    Lidar is a kind of active optical remote sensing instruments , can be applied to sound atmosphere with a high spatial and temporal resolution. Many parameter of atmosphere can be get by using different inverse algorithm with lidar backscatter signal. The basic setup of a lidar consist of a transmitter and a receiver. To make sure the quality of lidar signal data, the lidar must be calibrated before being used to measure the atmospheric variables. It is really significant to character and analyze lidar optical subsystem because a well equiped lidar optical subsystem contributes to high quality lidar signal data. we pay close attention to telecover test to character and analyze lidar optical subsystem.The telecover test is called four quadrants method consisting in dividing the telescope aperture in four quarants. when a lidar is well configured with lidar optical subsystem, the normalized signal from four qudrants will agree with each other on some level. Testing our WARL-II lidar by four quadrants method ,we find the signals of the four basically consistent with each other both in near range and in far range. But in detail, the signals in near range have some slight distinctions resulting from overlap function, some signals distinctions are induced by atmospheric instability.

  6. Fractal properties and denoising of lidar signals from cirrus clouds

    NARCIS (Netherlands)

    Heuvel, J.C. van den; Driesenaar, M.L.; Lerou, R.J.L.

    2000-01-01

    Airborne lidar signals of cirrus clouds are analyzed to determine the cloud structure. Climate modeling and numerical weather prediction benefit from accurate modeling of cirrus clouds. Airborne lidar measurements of the European Lidar in Space Technology Experiment (ELITE) campaign were analyzed by

  7. Lightweight Inexpensive Ozone Lidar Telescope Using a Plastic Fresnel Lens

    Science.gov (United States)

    DeYoung, Russell J.; Notari, Anthony; Carrion, William; Pliutau, Denis

    2014-01-01

    An inexpensive lightweight ozone lidar telescope was designed, constructed and operated during an ozone lidar field campaign. This report summarizes the design parameters and performance of the plastic Fresnel lens telescope and shows the ozone lidar performance compared to Zemax calculations.

  8. 3D pulsed chaos lidar system.

    Science.gov (United States)

    Cheng, Chih-Hao; Chen, Chih-Ying; Chen, Jun-Da; Pan, Da-Kung; Ting, Kai-Ting; Lin, Fan-Yi

    2018-04-30

    We develop an unprecedented 3D pulsed chaos lidar system for potential intelligent machinery applications. Benefited from the random nature of the chaos, conventional CW chaos lidars already possess excellent anti-jamming and anti-interference capabilities and have no range ambiguity. In our system, we further employ self-homodyning and time gating to generate a pulsed homodyned chaos to boost the energy-utilization efficiency. Compared to the original chaos, we show that the pulsed homodyned chaos improves the detection SNR by more than 20 dB. With a sampling rate of just 1.25 GS/s that has a native sampling spacing of 12 cm, we successfully achieve millimeter-level accuracy and precision in ranging. Compared with two commercial lidars tested side-by-side, namely the pulsed Spectroscan and the random-modulation continuous-wave Lidar-lite, the pulsed chaos lidar that is in compliance with the class-1 eye-safe regulation shows significantly better precision and a much longer detection range up to 100 m. Moreover, by employing a 2-axis MEMS mirror for active laser scanning, we also demonstrate real-time 3D imaging with errors of less than 4 mm in depth.

  9. Atmospheric Turbulence Estimates from a Pulsed Lidar

    Science.gov (United States)

    Pruis, Matthew J.; Delisi, Donald P.; Ahmad, Nash'at N.; Proctor, Fred H.

    2013-01-01

    Estimates of the eddy dissipation rate (EDR) were obtained from measurements made by a coherent pulsed lidar and compared with estimates from mesoscale model simulations and measurements from an in situ sonic anemometer at the Denver International Airport and with EDR estimates from the last observation time of the trailing vortex pair. The estimates of EDR from the lidar were obtained using two different methodologies. The two methodologies show consistent estimates of the vertical profiles. Comparison of EDR derived from the Weather Research and Forecast (WRF) mesoscale model with the in situ lidar estimates show good agreement during the daytime convective boundary layer, but the WRF simulations tend to overestimate EDR during the nighttime. The EDR estimates from a sonic anemometer located at 7.3 meters above ground level are approximately one order of magnitude greater than both the WRF and lidar estimates - which are from greater heights - during the daytime convective boundary layer and substantially greater during the nighttime stable boundary layer. The consistency of the EDR estimates from different methods suggests a reasonable ability to predict the temporal evolution of a spatially averaged vertical profile of EDR in an airport terminal area using a mesoscale model during the daytime convective boundary layer. In the stable nighttime boundary layer, there may be added value to EDR estimates provided by in situ lidar measurements.

  10. Linear LIDAR versus Geiger-mode LIDAR: impact on data properties and data quality

    Science.gov (United States)

    Ullrich, A.; Pfennigbauer, M.

    2016-05-01

    LIDAR has become the inevitable technology to provide accurate 3D data fast and reliably even in adverse measurement situations and harsh environments. It provides highly accurate point clouds with a significant number of additional valuable attributes per point. LIDAR systems based on Geiger-mode avalanche photo diode arrays, also called single photon avalanche photo diode arrays, earlier employed for military applications, now seek to enter the commercial market of 3D data acquisition, advertising higher point acquisition speeds from longer ranges compared to conventional techniques. Publications pointing out the advantages of these new systems refer to the other category of LIDAR as "linear LIDAR", as the prime receiver element for detecting the laser echo pulses - avalanche photo diodes - are used in a linear mode of operation. We analyze the differences between the two LIDAR technologies and the fundamental differences in the data they provide. The limitations imposed by physics on both approaches to LIDAR are also addressed and advantages of linear LIDAR over the photon counting approach are discussed.

  11. Long-term Aerosol Lidar Measurements At CNR-IMAA

    Science.gov (United States)

    Mona, L.; Amodeo, A.; D'Amico, G.; Pandolfi, M.; Pappalardo, G.

    2006-12-01

    Actual estimations of the aerosol effect on the radiation budget are affected by a large uncertainties mainly due to the high inhomogeneity and variability of atmospheric aerosol, in terms of concentration, shape, size distribution, refractive index and vertical distribution. Long-term measurements of vertical profiles of aerosol optical properties are needed to reduce these uncertainties. At CNR-IMAA (40° 36'N, 15° 44' E, 760 m above sea level), a lidar system for aerosol study is operative since May 2000 in the framework of EARLINET (European Aerosol Research Lidar Network). Until August 2005, it provided independent measurements of aerosol extinction and backscatter at 355 nm and aerosol backscatter profiles at 532 nm. After an upgrade of the system, it provides independent measurements of aerosol extinction and backscatter profiles at 355 and 532 nm, and of aerosol backscatter profiles at 1064 nm and depolarization ratio at 532 nm. For these measurements, lidar ratio at 355 and 532 nm and Angstrom exponent profiles at 355/532 nm are also obtained. Starting on May 2000, systematic measurements are performed three times per week according to the EARLINET schedule and further measurements are performed in order to investigate particular events, like dust intrusions, volcanic eruptions and forest fires. A climatological study has been carried out in terms of the seasonal behavior of the PBL height and of the aerosol optical properties calculated inside the PBL itself. In the free troposphere, an high occurrences of Saharan dust intrusions (about 1 day of Saharan dust intrusion every 10 days) has been observed at CNR-IMAA because of the short distance from the Sahara region. During 6 years of observations, very peculiar cases of volcanic aerosol emitted by Etna volcano and aerosol released by large forest fires burning occurred in Alaska and Canada have been observed in the free troposphere at our site. Particular attention is devoted to lidar ratio both for the

  12. Evaluation of the Wind Flow Variability Using Scanning Doppler Lidar Measurements

    Science.gov (United States)

    Sand, S. C.; Pichugina, Y. L.; Brewer, A.

    2016-12-01

    Better understanding of the wind flow variability at the heights of the modern turbines is essential to accurately assess of generated wind power and efficient turbine operations. Nowadays the wind energy industry often utilizes scanning Doppler lidar to measure wind-speed profiles at high spatial and temporal resolution.The study presents wind flow features captured by scanning Doppler lidars during the second Wind Forecast and Improvement Project (WFIP 2) sponsored by the Department of Energy (DOE) and National Oceanic and Atmospheric Administration (NOAA). This 18-month long experiment in the Columbia River Basin aims to improve model wind forecasts complicated by mountain terrain, coastal effects, and numerous wind farms.To provide a comprehensive dataset to use for characterizing and predicting meteorological phenomena important to Wind Energy, NOAA deployed scanning, pulsed Doppler lidars to two sites in Oregon, one at Wasco, located upstream of all wind farms relative to the predominant westerly flow in the region, and one at Arlington, located in the middle of several wind farms.In this presentation we will describe lidar scanning patterns capable of providing data in conical, or vertical-slice modes. These individual scans were processed to obtain 15-min averaged profiles of wind speed and direction in real time. Visualization of these profiles as time-height cross sections allows us to analyze variability of these parameters with height, time and location, and reveal periods of rapid changes (ramp events). Examples of wind flow variability between two sites of lidar measurements along with examples of reduced wind velocity downwind of operating turbines (wakes) will be presented.

  13. Excess noise in Lidar Thomson scattering methods

    International Nuclear Information System (INIS)

    Smith, R J; Drake, L A P; Lestz, J B

    2012-01-01

    Fundamental detection limits for the Lidar Thomson scattering technique and in particular pulsed polarimetry are presented for the first time for the long wavelength limit of incoherent Thomson scattering. Pulsed polarimetry generalizes Lidar Thomson scattering to include local magnetic field sensing. The implication for these techniques is explored for two experimental regimes where shot limited detection no longer applies: tokamaks of ITER size and cm-size wire Z pinch plasmas of High Energy Density (HED) science. The utility and importance of developing Lidar Thomson scattering at longer wavelengths for the magnetic fusion program is illustrated by a study of sightline (local) polarimetry measurements on a 15MA ITER scenario. Polarimetric measurements in the far infrared regime are shown to reach sensitivities that are instructive and useful but with a complex behaviour that make spatially resolved measurements all but mandatory.

  14. Atmospheric lidar: Legal, scientific and technological aspects

    International Nuclear Information System (INIS)

    Barbini, R.; Colao, F.; Fiorani, L.; Palucci, A.

    2000-01-01

    The Atmospheric Lidar is one of the systems of the Mobile Laboratory of Laser Remote Sensing under development at the ENEA Research Center of Frascati. This technical report addresses the legislative, scientific and technological aspects that are the basis for the identification of the requirements, the definition of the architecture and the fixation of the specifications of the Atmospheric Lidar. The problems of air pollution are introduced in section 2. A summary of the Italian laws on that topic is then given. Section 4 provides a survey of the atmospheric measurements that can be achieved with the lidar. The sensitivity in the monitoring of pollutants is discussed in section 5. The other systems of the Mobile Laboratory of Laser Remote Sensing are shortly described in section 6. The last section is devoted to conclusions and perspectives [it

  15. Fusion of LiDAR and aerial imagery for the estimation of downed tree volume using Support Vector Machines classification and region based object fitting

    Science.gov (United States)

    Selvarajan, Sowmya

    downed tree classification with fused LiDAR and aerial image. The classified tree pixels are utilized in the object based region fitting technique to compute the diameter and height of the downed trees and the volume of the trees are estimated. (Full text of this dissertation may be available via the University of Florida Libraries web site. Please check http://www.uflib.ufl.edu/etd.html)

  16. Light Detection and Ranging (LIDAR) From Space - Laser Altimeters

    Science.gov (United States)

    Sun, Xiaoli

    2016-01-01

    Light detection and ranging, or lidar, is like radar but atoptical wavelengths. The principle of operation and theirapplications in remote sensing are similar. Lidars havemany advantages over radars in instrument designs andapplications because of the much shorter laser wavelengthsand narrower beams. The lidar transmitters and receiveroptics are much smaller than radar antenna dishes. Thespatial resolution of lidar measurement is much finer thanthat of radar because of the much smaller footprint size onground. Lidar measurements usually give a better temporalresolution because the laser pulses can be much narrowerthan radio frequency (RF) signals. The major limitation oflidar is the ability to penetrate clouds and ground surfaces.

  17. Complex Urban LiDAR Data Set

    OpenAIRE

    Jeong, Jinyong; Cho, Younggun; Shin, Young-Sik; Roh, Hyunchul; Kim, Ayoung

    2018-01-01

    This paper presents a Light Detection and Ranging (LiDAR) data set that targets complex urban environments. Urban environments with high-rise buildings and congested traffic pose a significant challenge for many robotics applications. The presented data set is unique in the sense it is able to capture the genuine features of an urban environment (e.g. metropolitan areas, large building complexes and underground parking lots). Data of two-dimensional (2D) and threedimensional (3D) LiDAR, which...

  18. LIDAR, Point Clouds, and their Archaeological Applications

    Energy Technology Data Exchange (ETDEWEB)

    White, Devin A [ORNL

    2013-01-01

    It is common in contemporary archaeological literature, in papers at archaeological conferences, and in grant proposals to see heritage professionals use the term LIDAR to refer to high spatial resolution digital elevation models and the technology used to produce them. The goal of this chapter is to break that association and introduce archaeologists to the world of point clouds, in which LIDAR is only one member of a larger family of techniques to obtain, visualize, and analyze three-dimensional measurements of archaeological features. After describing how point clouds are constructed, there is a brief discussion on the currently available software and analytical techniques designed to make sense of them.

  19. Lidar for Wind and Optical Turbulence Profiling

    Directory of Open Access Journals (Sweden)

    Fastig Shlomo

    2018-01-01

    Full Text Available A field campaign for the comparison investigation of systems to measure wind and optical turbulence profiles was conducted in northern Germany. The experimental effort was to compare the performance of the LIDAR, SODAR-RASS and ultrasonic anemometers for the measurement of the above mentioned atmospheric parameters. Soreq's LIDAR is a fiber laser based system demonstrator for the vertical profiling of the wind and turbulence, based on the correlation of aerosol density variations. It provides measurements up to 350m with 20m resolution.

  20. Wind Lidar Activities in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, Andrew; Newman, Jennifer; St. Pe, Alexandra; Iungo, G. Valerio; Wharton, Sonia; Herges, Tommy; Filippelli, Matthew; Pontbriand, Philippe; Osler, Evan

    2017-06-28

    IEA Wind Task 32 seeks to identify and mitigate the barriers to the adoption of lidar for wind energy applications. This work is partly achieved by sharing experience across researchers and practitioners in the United States and worldwide. This presentation is a short summary of some wind lidar-related activities taking place in the country, and was presented by Andrew Clifton at the Task 32 meeting in December 2016 in his role as the U.S. Department of Energy-nominated country representative to the task.

  1. Development of atmospheric polarization LIDAR System

    International Nuclear Information System (INIS)

    Ghalumyan, A.S.; Ghazaryan, V.R.

    2016-01-01

    LIDAR (Light Detection And Ranging) system sensitive to the polarization of the backscattered signal is being developed in Yerevan Physics Institute. The system is designed primarily for remote sensing of the atmospheric electric fields. At present, the system is being tuned for measuring vertical atmospheric backscatter profiles of aerosols and hydrometeors, analyze the depolarization ratio of elastic backscattered laser beams and investigate the influence of external factors on the beam polarization. In this paper, we describe the complete LIDAR system – the laser transmitter, receiving telescope and the polarization separator. The data acquisition and processing techniques are also described. (author)

  2. Cloud fraction and cloud base measurements from scanning Doppler lidar during WFIP-2

    Science.gov (United States)

    Bonin, T.; Long, C.; Lantz, K. O.; Choukulkar, A.; Pichugina, Y. L.; McCarty, B.; Banta, R. M.; Brewer, A.; Marquis, M.

    2017-12-01

    The second Wind Forecast Improvement Project (WFIP-2) consisted of an 18-month field deployment of a variety of instrumentation with the principle objective of validating and improving NWP forecasts for wind energy applications in complex terrain. As a part of the set of instrumentation, several scanning Doppler lidars were installed across the study domain to primarily measure profiles of the mean wind and turbulence at high-resolution within the planetary boundary layer. In addition to these measurements, Doppler lidar observations can be used to directly quantify the cloud fraction and cloud base, since clouds appear as a high backscatter return. These supplementary measurements of clouds can then be used to validate cloud cover and other properties in NWP output. Herein, statistics of the cloud fraction and cloud base height from the duration of WFIP-2 are presented. Additionally, these cloud fraction estimates from Doppler lidar are compared with similar measurements from a Total Sky Imager and Radiative Flux Analysis (RadFlux) retrievals at the Wasco site. During mostly cloudy to overcast conditions, estimates of the cloud radiating temperature from the RadFlux methodology are also compared with Doppler lidar measured cloud base height.

  3. CALIPSO-Inferred Aerosol Direct Radiative Effects: Bias Estimates Using Ground-Based Raman Lidars

    Science.gov (United States)

    Thorsen, Tyler; Fu, Qiang

    2016-01-01

    Observational constraints on the change in the radiative energy budget caused by the presence of aerosols, i.e. the aerosol direct radiative effect (DRE), have recently been made using observations from the Cloud- Aerosol Lidar and Infrared Pathfinder Satellite (CALIPSO). CALIPSO observations have the potential to provide improved global estimates of aerosol DRE compared to passive sensor-derived estimates due to CALIPSO's ability to perform vertically-resolved aerosol retrievals over all surface types and over cloud. In this study we estimate the uncertainties in CALIPSO-inferred aerosol DRE using multiple years of observations from the Atmospheric Radiation Measurement (ARM) program's Raman lidars (RL) at midlatitude and tropical sites. Examined are assumptions about the ratio of extinction-to-backscatter (i.e. the lidar ratio) made by the CALIPSO retrievals, which are needed to retrieve the aerosol extinction profile. The lidar ratio is shown to introduce minimal error in the mean aerosol DRE at the top-of-atmosphere and surface. It is also shown that CALIPSO is unable to detect all radiatively-significant aerosol, resulting in an underestimate in the magnitude of the aerosol DRE by 30-50%. Therefore, global estimates of the aerosol DRE inferred from CALIPSO observations are likely too weak.

  4. Assessment of particle emissions inventories in northeastern U.S., using remote sensing, Lidar technology, air pollution sensors, and a Lagrangian particle dispersion model

    Science.gov (United States)

    Barrera, Y.; Swofsy, S. C.; Li, L.; Hegarty, J. D.; Nehrkorn, T.; Koutrakis, P.

    2017-12-01

    In the most recent issue of the New England Journal of Medicine, a new study found that 95% of Medicare beneficiaries over the age of 65 showed an increased risk of mortality, even at fine particulate matter (PM2.5) levels below the National Ambient Air Quality Standards (NAAQS). This new finding suggests that although a state may be designated under attainment for meeting the primary and secondary PM2.5 NAAQS, sensitive populations dispersed throughout the region may still be experiencing adverse health effects. To conduct accurate public health impact assessments, reliable information regarding PM2.5 concentrations in cities are required at high spatial and temporal resolutions. A newly developed particle emissions inventory using remote sensing (PEIRS) captured both primary and secondary formation in northeastern U.S. at a 1km x 1km spatial resolution during the period 2002-2014 (Tang et al., 2017). The PEIRS annual emissions inventory used the MODIS satellite to fill-in the spatial gaps where, EPA monitoring stations were not available. However, simulations of the planetary boundary layer (PBL) were a key factor in estimating PM2.5 concentrations on the ground and hence, testing PEIRS products with observationally based quantifications are critical. Recent advances in light ranging and detection (Lidar) technology allow us to estimate PBL heights in cities. This study combines information from a network of Mini Micropulse Lidar (MPL) instruments, meteorological and air pollution measuring sensors, and a Lagrangian particle dispersion model to test the performance of PEIRS at the neighborhood and urban scale. MPL observations were processed using image recognition and fuzzy logic to estimate PBL heights that were inputted into PEIRS to predict daily PM2.5 concentrations. To compare vertical distribution of aerosols, we use our LPDM model "footprints" to predict vertical profiles of PM2.5 distribution at our Lidar locations. Our model-data assimilation improved

  5. A categorical, improper probability method for combining NDVI and LiDAR elevation information for potential cotton precision agricultural applications

    Science.gov (United States)

    An algorithm is presented to fuse the Normalized Difference Vegetation Index (NDVI) with Light Detection and Ranging (LiDAR) elevation data to produce a map potentially useful for the site-specific scouting and pest management of several insect pests. In cotton, these pests include the Tarnished Pl...

  6. MPL-net at ARM Sites

    Science.gov (United States)

    Spinhirne, J. D.; Welton, E. J.; Campbell, J. R.; Berkoff, T. A.; Starr, David OC. (Technical Monitor)

    2002-01-01

    The NASA MPL-net project goal is consistent data products of the vertical distribution of clouds and aerosol from globally distributed lidar observation sites. The four ARM micro pulse lidars are a basis of the network to consist of over twelve sites. The science objective is ground truth for global satellite retrievals and accurate vertical distribution information in combination with surface radiation measurements for aerosol and cloud models. The project involves improvement in instruments and data processing and cooperation with ARM and other partners.

  7. 2000 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Kitsap Peninsula, Washington

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TerraPoint surveyed and created this data for the Puget Sound LiDAR Consortium under contract. The area surveyed is approximately 1,146 square miles and covers part...

  8. 2003 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Snohomish County, Washington

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TerraPoint surveyed and created this data for the Puget Sound LiDAR Consortium under contract. The area surveyed is approximately 167 square miles and covers a...

  9. 2011 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Rattlesnake

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. (WSI) collected Light Detection and Ranging (LiDAR) data on six days between September 15th and November 5th, and from November 6th - 13th,...

  10. 2005 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: North Puget Sound Lowlands

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Terrapoint collected Light Detection and Ranging (LiDAR) data contributing to the Puget Sound Lowlands project of 2005. Arlington, City of Snohomish, Snohomish...

  11. 2005 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Lower Columbia River

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Terrapoint, on behalf of multiple agencies, collected topographic lidar of the Lower Columbia River area. Field data collection took place between the dates of...

  12. 2003 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Lewis County, Washington

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TerraPoint surveyed and created this data for the Puget Sound LiDAR Consortium under contract. The area surveyed is approximately 100 square miles and covers part of...

  13. 2013 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Nooksack

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In July 2012, WSI (Watershed Sciences, Inc.) was contracted by the Puget Sound LiDARConsortium (PSLC) to collect Light Detection and Ranging (LiDAR) data on a...

  14. 2005 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Olympic Peninsula

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Terrapoint collected Light Detection and Ranging (LiDAR) data for the Olympic Peninsula project of 2005, totaling approximately 114.59 sq mi: 24.5 for Clallam...

  15. 2012 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Upper Naches River, Washington

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. (WSI) collected Light Detection and Ranging (LiDAR) data of the Upper Naches River Valley and Nile Slide area of interest on September 30th,...

  16. 2013 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Entiat

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In October 2012, WSI (Watershed Sciences, Inc.) was contracted by the Puget Sound LiDARConsortium (PSLC) to collect Light Detection and Ranging (LiDAR) data for the...

  17. Field evaluation of remote wind sensing technologies: Shore-based and buoy mounted LIDAR systems

    Energy Technology Data Exchange (ETDEWEB)

    Herrington, Thomas [Stevens Inst. of Technology, Hoboken, NJ (United States)

    2017-11-03

    will be transferred to the Garrad Hassan (a subcontractor to Fishermen’s Energy) for incorporation in to the validation database, which is accessible to other scientific team members. Data collection times and durations will be determined by the PI and Co-PIs in consultation with instrument engineers to ensure the capture of data representative of the expected range of mid-Atlantic atmospheric conditions (e.g., temperature, moisture, coastal low pressure systems, tropical systems, rain, snow, fog). The collection and processing of the data is a function of site specific measurement requirements (Kelley et.al. 2007; Hannon et.al. 2008). To determine the optimal profiles of wind speed and direction from the LIDAR radial velocities as a function of azimuth angle, rigorous estimates of the bias and random error of each radial velocity estimate are required. Lockheed Martin Coherent Technologies, Inc., under contract with Fishermen’s Energy, will provide analyses of raw and processed data using various scan patterns to determine optimal performance settings for the pulsed scanning LIDAR. Once optimized, appropriate processing and analyses techniques will be evaluated by Garrad Hassan for use in validating the accuracy of the LIDAR wind field measurements against the standard anemometer measurements from the meteorological masts. The most attractive capability of the scanning LIDAR is the ability to provide high spatial resolution observations in a three-dimensional volume which provides superior statistical accuracy due to the large number of samples obtained. Each radial scan provides measurements in 100 range gates over a distance of 10 to 12 km at an update rate of 5 to 10 Hz and rotation of 2.5° per second. Each rotation at a fixed azimuth requires 2.4 minutes. Depending on the number of azimuths desired a complete scan can take up to 10 minutes or longer to complete. Once collected the radial velocities are processed to produce vector wind velocity estimates based

  18. Analysis of elevation changes detected from multi-temporal LiDAR surveys in forested landslide terrain in western Oregon

    Science.gov (United States)

    Burns, W.J.; Coe, J.A.; Kaya, B.S.; Ma, Liwang

    2010-01-01

    We examined elevation changes detected from two successive sets of Light Detection and Ranging (LiDAR) data in the northern Coast Range of Oregon. The first set of LiDAR data was acquired during leafon conditions and the second set during leaf-off conditions. We were able to successfully identify and map active landslides using a differential digital elevation model (DEM) created from the two LiDAR data sets, but this required the use of thresholds (0.50 and 0.75 m) to remove noise from the differential elevation data, visual pattern recognition of landslideinduced elevation changes, and supplemental QuickBird satellite imagery. After mapping, we field-verified 88 percent of the landslides that we had mapped with high confidence, but we could not detect active landslides with elevation changes of less than 0.50 m. Volumetric calculations showed that a total of about 18,100 m3 of material was missing from landslide areas, probably as a result of systematic negative elevation errors in the differential DEM and as a result of removal of material by erosion and transport. We also examined the accuracies of 285 leaf-off LiDAR elevations at four landslide sites using Global Positioning System and total station surveys. A comparison of LiDAR and survey data indicated an overall root mean square error of 0.50 m, a maximum error of 2.21 m, and a systematic error of 0.09 m. LiDAR ground-point densities were lowest in areas with young conifer forests and deciduous vegetation, which resulted in extensive interpolations of elevations in the leaf-on, bare-earth DEM. For optimal use of multi-temporal LiDAR data in forested areas, we recommend that all data sets be flown during leaf-off seasons.

  19. PollyNET - an emerging network of automated raman-polarizarion lidars for continuous aerosolprofiling

    Science.gov (United States)

    Baars, Holger; Althausen, Dietrich; Engelmann, Ronny; Heese, Birgit; Ansmann, Albert; Wandinger, Ulla; Hofer, Julian; Skupin, Annett; Komppula, Mika; Giannakaki, Eleni; Filioglou, Maria; Bortoli, Daniele; Silva, Ana Maria; Pereira, Sergio; Stachlewska, Iwona S.; Kumala, Wojciech; Szczepanik, Dominika; Amiridis, Vassilis; Marinou, Eleni; Kottas, Michail; Mattis, Ina; Müller, Gerhard

    2018-04-01

    PollyNET is a network of portable, automated, and continuously measuring Ramanpolarization lidars of type Polly operated by several institutes worldwide. The data from permanent and temporary measurements sites are automatically processed in terms of optical aerosol profiles and displayed in near-real time at polly.tropos.de. According to current schedules, the network will grow by 3-4 systems during the upcoming 2-3 years and will then comprise 11 permanent stations and 2 mobile platforms.

  20. Feasibility of tropospheric water vapor profiling using infrared heterodyne differential absorption lidar

    Energy Technology Data Exchange (ETDEWEB)

    Grund, C.J.; Hardesty, R.M. [National Oceanic and Atmospheric Administration Environmental Technology Laboratoy, Boulder, CO (United States); Rye, B.J. [Univ. of Colorado, Boulder, CO (United States)

    1996-04-01

    The development and verification of realistic climate model parameterizations for clouds and net radiation balance and the correction of other site sensor observations for interferences due to the presence of water vapor are critically dependent on water vapor profile measurements. In this study, we develop system performance models and examine the potential of infrared differential absoroption lidar (DIAL) to determine the concentration of water vapor.

  1. Optics of the ozone lidar ELSA

    Science.gov (United States)

    Porteneuve, J.

    1992-01-01

    In order to study the ozone layer in the Arctic, we have to define a new optical concept for a lidar. It was necessary to build a transportable system with a large collecting surface in a minimum of volume. It was too useful to have a multichannel receptor. A description of the Emettor Receptor System, collecting system, and analysis system is provided.

  2. Airborne Lidar Surface Topography (LIST) Simulator

    Science.gov (United States)

    Yu, Anthony W.; Krainak, Michael A.; Harding, David J.; Abshire, James B.; Sun, Xiaoli; Cavanaugh, John; Valett, Susan; Ramos-Izquierdo, Luis; Winkert, Tom; Plants, Michael; hide

    2011-01-01

    In this paper we will discuss our development effort of an airborne instrument as a pathfinder for the Lidar Surface Technology (LIST) mission. This paper will discuss the system approach, enabling technologies, instrument concept and performance of the Airborne LIST Simulator (A-LISTS).

  3. Lidar Architecture for Harsh Environment Applications

    Directory of Open Access Journals (Sweden)

    Church Philip

    2016-01-01

    Full Text Available An overview is provided of the obscurantpenetrating OPAL lidar sensor developed for harsh environments, including poor visibility conditions. The underlying technology, hardware and software architecture of the sensor are presented along with some examples of its software modules’ applications. The paper also discusses the performance of the OPAL in the presence of various types of obscurants.

  4. The LIDAR Thomson Scattering Diagnostic on JET

    DEFF Research Database (Denmark)

    Salzmann, H.; Bundgaard, J.; Gadd, A.

    1988-01-01

    By combining the time‐of‐flight or LIDAR principle with a Thomson backscatter diagnostic, spatial profiles of the electron temperature and density are measured in a magnetically confined fusion plasma. This technique was realized for the first time on the JET tokamak. A ruby laser (3‐J pulse ener...

  5. 2008 FEMA Lidar: South Oneida County (NY)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — For Oneida County, NY, there were two types of elevation datasets. The first type is LiDAR and the second one is Auto-correlation DEM. Auto-correlation DEM data was...

  6. Project ABLE: (Atmospheric Balloonborne Lidar Experiment)

    Science.gov (United States)

    Shepherd, O.; Aurilio, G.; Bucknam, R. D.; Hurd, A. G.; Sheehan, W. H.

    1985-03-01

    Project ABLE (Atmospheric Balloonborne Lidar Experiment) is part of the A.F. Geophysics Laboratory's continuing interest in developing techniques for making remote measurements of atmospheric quantities such as density, pressure, temperatures, and wind motions. The system consists of a balloonborne lidar payload designed to measure neutral molecular density as a function of altitude from ground level to 70 km. The lidar provides backscatter data at the doubled and tripled frequencies of a Nd:YAG laser, which will assist in the separation of the molecular and aerosol contributions and subsequent determination of molecular and aerosol contributions and subsequent determination of molecular density vs altitude. The object of this contract was to fabricate and operate in a field test a balloonborne lidar experiment capable of performing nighttime atmospheric density measurements up to 70 km altitude with a resolution of 150 meters. The payload included a frequency-doubled and -tripled Nd:YAG laser with outputs at 355 and 532 nm; a telescoped receiver with PMT detectors; a command-controlled optical pointing system; and support system, including thermal control, telmetry, command, and power. Successful backscatter measurements were made during field operations which included a balloon launch from Roswell, NM and a flight over the White Sands Missile Range.

  7. Field test of a lidar wind profiler

    NARCIS (Netherlands)

    Kunz, G.J.

    1996-01-01

    Wind speeds and wind directions are measured remotely using an incoherent backscatter lidar system operating at a wavelength of 1.06 mm with a maximum repetition rate of 13 Hz. The principle of the measurements is based on following detectable atmospheric structures, which are transported by the

  8. 2009 USGS Potato Creek Lidar Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — LiDAR collected for the upper portion of the Flint River in central georgia. 237.6 sqmiles collected between May 1st and May 4th, 2009. The data contains 1 meter...

  9. Water Mapping Using Multispectral Airborne LIDAR Data

    Science.gov (United States)

    Yan, W. Y.; Shaker, A.; LaRocque, P. E.

    2018-04-01

    This study investigates the use of the world's first multispectral airborne LiDAR sensor, Optech Titan, manufactured by Teledyne Optech to serve the purpose of automatic land-water classification with a particular focus on near shore region and river environment. Although there exist recent studies utilizing airborne LiDAR data for shoreline detection and water surface mapping, the majority of them only perform experimental testing on clipped data subset or rely on data fusion with aerial/satellite image. In addition, most of the existing approaches require manual intervention or existing tidal/datum data for sample collection of training data. To tackle the drawbacks of previous approaches, we propose and develop an automatic data processing workflow for land-water classification using multispectral airborne LiDAR data. Depending on the nature of the study scene, two methods are proposed for automatic training data selection. The first method utilizes the elevation/intensity histogram fitted with Gaussian mixture model (GMM) to preliminarily split the land and water bodies. The second method mainly relies on the use of a newly developed scan line elevation intensity ratio (SLIER) to estimate the water surface data points. Regardless of the training methods being used, feature spaces can be constructed using the multispectral LiDAR intensity, elevation and other features derived from these parameters. The comprehensive workflow was tested with two datasets collected for different near shore region and river environment, where the overall accuracy yielded better than 96 %.

  10. Voxel-Based LIDAR Analysis and Applications

    Science.gov (United States)

    Hagstrom, Shea T.

    One of the greatest recent changes in the field of remote sensing is the addition of high-quality Light Detection and Ranging (LIDAR) instruments. In particular, the past few decades have been greatly beneficial to these systems because of increases in data collection speed and accuracy, as well as a reduction in the costs of components. These improvements allow modern airborne instruments to resolve sub-meter details, making them ideal for a wide variety of applications. Because LIDAR uses active illumination to capture 3D information, its output is fundamentally different from other modalities. Despite this difference, LIDAR datasets are often processed using methods appropriate for 2D images and that do not take advantage of its primary virtue of 3-dimensional data. It is this problem we explore by using volumetric voxel modeling. Voxel-based analysis has been used in many applications, especially medical imaging, but rarely in traditional remote sensing. In part this is because the memory requirements are substantial when handling large areas, but with modern computing and storage this is no longer a significant impediment. Our reason for using voxels to model scenes from LIDAR data is that there are several advantages over standard triangle-based models, including better handling of overlapping surfaces and complex shapes. We show how incorporating system position information from early in the LIDAR point cloud generation process allows radiometrically-correct transmission and other novel voxel properties to be recovered. This voxelization technique is validated on simulated data using the Digital Imaging and Remote Sensing Image Generation (DIRSIG) software, a first-principles based ray-tracer developed at the Rochester Institute of Technology. Voxel-based modeling of LIDAR can be useful on its own, but we believe its primary advantage is when applied to problems where simpler surface-based 3D models conflict with the requirement of realistic geometry. To

  11. Modeling and analysis of Off-beam lidar returns from thick clouds, snow, and sea ice

    International Nuclear Information System (INIS)

    Varnai, T.; Cahalan, R. F.

    2009-01-01

    A group of recently developed lidar (laser ranging and detection) systems can detect signals returning from several wide field-of-views, allowing them to observe the way laser pulses spread in thick media. The new capability enabled accurate measurements of cloud geometrical thickness and promises improved measurements of internal cloud structure as well as snow and sea ice thickness. This paper presents a brief overview of radiation transport simulation techniques and data analysis methods that were developed for multi-view lidar applications and for and considering multiple scattering effects in single-view lidar data. In discussing methods for simulating the three-dimensional spread of lidar pulses, we present initial results from Phase 3 of the Intercomparison of 3-D Radiation Codes (I3RC) project. The results reveal some differences in the capabilities of participating models, while good agreement among several models provides consensus results suitable for testing future models. Detailed numerical results are available at the I3RC web site at http://i3rc.gsfc.nasa. gov. In considering data analysis methods, we focus on the Thickness from Off-beam Returns (THOR) lidar. THOR proved successful in measuring the geometrical thickness of optically thick clouds; here we focus on its potential for retrieving the vertical profile of scattering coefficient in clouds and for measuring snow thickness. Initial observations suggest considerable promise but also reveal some limitations, for example that the maximum retrievable snow thickness drops from about 0.5 m in pristine areas to about 0.15 m in polluted regions. (authors)

  12. Extensive Sampling of Forest Carbon using High Density Power Line Lidar

    Science.gov (United States)

    Hampton, H. M.; Chen, Q.; Dye, D. G.; Hungate, B. A.

    2013-12-01

    Estimating carbon sequestration and greenhouse gas emissions from forest management, natural processes, and disturbance is of growing interest for mitigating global warming. Ponderosa pine is common at mid-elevations throughout the western United States and is a dominant tree species in southwestern forests. Existing unmanaged "relict" sites and stand reconstructions of southwestern ponderosa pine forests from before European settlement (late 1800s) provide evidence of forests of larger trees of lower density and less vulnerability to severe fires than today's typical conditions of high densities of small trees that have resulted from a century of fire suppression. Forest treatments to improve forest health in the region include tree cutting focused on small-diameter trees (thinning), low-intensity prescribed burning, and monitoring rather than suppressing wildfires. Stimulated by several uncharacteristically-intense fires in the last decade, a collaborative process found strong stakeholder agreement to accelerate forest treatments to reduce fire risk and restore ecological conditions. Land use planning to ramp up management is underway and could benefit from quick and inexpensive techniques to inventory tree-level carbon because existing inventory data are not adequate to capture the range of forest structural conditions. Our approach overcomes these shortcomings by employing recent breakthroughs in estimating aboveground biomass from high resolution light detection and ranging (lidar) remote sensing. Lidar is an active remote sensing technique, analogous to radar, which measures the time required for a transmitted pulse of laser light to return to the sensor after reflection from a target. Lidar data can capture 3-dimensional forest structure with greater detail and broader spatial coverage than is feasible with conventional field measurements. We developed a novel methodology for extensive sampling and field validation of forest carbon, applicable to managed and

  13. Using Satellite and Airborne LiDAR to Model Woodpecker Habitat Occupancy at the Landscape Scale

    Science.gov (United States)

    Vierling, Lee A.; Vierling, Kerri T.; Adam, Patrick; Hudak, Andrew T.

    2013-01-01

    Incorporating vertical vegetation structure into models of animal distributions can improve understanding of the patterns and processes governing habitat selection. LiDAR can provide such structural information, but these data are typically collected via aircraft and thus are limited in spatial extent. Our objective was to explore the utility of satellite-based LiDAR data from the Geoscience Laser Altimeter System (GLAS) relative to airborne-based LiDAR to model the north Idaho breeding distribution of a forest-dependent ecosystem engineer, the Red-naped sapsucker (Sphyrapicus nuchalis). GLAS data occurred within ca. 64 m diameter ellipses spaced a minimum of 172 m apart, and all occupancy analyses were confined to this grain scale. Using a hierarchical approach, we modeled Red-naped sapsucker occupancy as a function of LiDAR metrics derived from both platforms. Occupancy models based on satellite data were weak, possibly because the data within the GLAS ellipse did not fully represent habitat characteristics important for this species. The most important structural variables influencing Red-naped Sapsucker breeding site selection based on airborne LiDAR data included foliage height diversity, the distance between major strata in the canopy vertical profile, and the vegetation density near the ground. These characteristics are consistent with the diversity of foraging activities exhibited by this species. To our knowledge, this study represents the first to examine the utility of satellite-based LiDAR to model animal distributions. The large area of each GLAS ellipse and the non-contiguous nature of GLAS data may pose significant challenges for wildlife distribution modeling; nevertheless these data can provide useful information on ecosystem vertical structure, particularly in areas of gentle terrain. Additional work is thus warranted to utilize LiDAR datasets collected from both airborne and past and future satellite platforms (e.g. GLAS, and the planned IceSAT2

  14. High Spectral Resolution Lidar and MPLNET Micro Pulse Lidar Aerosol Optical Property Retrieval Intercomparison During the 2012 7-SEAS Field Campaign at Singapore

    Science.gov (United States)

    Lolli, Simone; Welton, Ellsworth J.; Campbell, James R.; Eloranta, Edwin; Holben, Brent N.; Chew, Boon Ning; Salinas, Santo V.

    2014-01-01

    From August 2012 to February 2013 a High Resolution Spectral Lidar (HSRL; 532 nm) was deployed at that National University of Singapore near a NASA Micro Pulse Lidar NETwork (MPLNET; 527 nm) site. A primary objective of the MPLNET lidar project is the production and dissemination of reliable Level 1 measurements and Level 2 retrieval products. This paper characterizes and quantifies error in Level 2 aerosol optical property retrievals conducted through inversion techniques that derive backscattering and extinction coefficients from MPLNET elastic single-wavelength datasets. MPLNET Level 2 retrievals for aerosol optical depth and extinction/backscatter coefficient profiles are compared with corresponding HSRL datasets, for which the instrument collects direct measurements of each using a unique optical configuration that segregates aerosol and cloud backscattered signal from molecular signal. The intercomparison is performed, and error matrices reported, for lower (0-5km) and the upper (>5km) troposphere, respectively, to distinguish uncertainties observed within and above the MPLNET instrument optical overlap regime.

  15. 2014 U.S. Geological Survey CMGP LiDAR: Post Sandy (New Jersey)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: USGS New Jersey CMGP Sandy Lidar 0.7 Meter NPS LIDAR lidar Data Acquisition and Processing Production Task USGS Contract No. G10PC00057 Task Order No....

  16. Standards – An Important Step for the (Public Use of Lidars

    Directory of Open Access Journals (Sweden)

    Althausen Dietrich

    2016-01-01

    Full Text Available Lidar standards are needed to ensure quality and lidar product control at the interface between lidar manufacturers and lidar users. Meanwhile three lidar standards have been published by German and international standardization organizations. This paper describes the cooperation between the lidar technique inventors, lidar instrument constructors, and lidar product users to establish useful standards. Presently a backscatter lidar standard is elaborated in Germany. Key points of this standard are presented here. Two German standards were already accepted as international standards by the International Organization for Standardization (ISO. Hence, German and international organizations for the establishment of lidar standards are introduced to encourage a cooperative work on lidar standards by lidar scientists.

  17. Illuminating wildfire erosion and deposition patterns with repeat terrestrial lidar

    Science.gov (United States)

    Rengers, Francis K.; Tucker, G.E.; Moody, J.A.; Ebel, Brian

    2016-01-01

    Erosion following a wildfire is much greater than background erosion in forests because of wildfire-induced changes to soil erodibility and water infiltration. While many previous studies have documented post-wildfire erosion with point and small plot-scale measurements, the spatial distribution of post-fire erosion patterns at the watershed scale remains largely unexplored. In this study lidar surveys were collected periodically in a small, first-order drainage basin over a period of 2 years following a wildfire. The study site was relatively steep with slopes ranging from 17° to > 30°. During the study period, several different types of rain storms occurred on the site including low-intensity frontal storms (2.4 mm h−1) and high-intensity convective thunderstorms (79 mm h−1). These storms were the dominant drivers of erosion. Erosion resulting from dry ravel and debris flows was notably absent at the site. Successive lidar surveys were subtracted from one another to obtain digital maps of topographic change between surveys. The results show an evolution in geomorphic response, such that the erosional response after rain storms was strongly influenced by the previous erosional events and pre-fire site morphology. Hillslope and channel roughness increased over time, and the watershed armored as coarse cobbles and boulders were exposed. The erosional response was spatially nonuniform; shallow erosion from hillslopes (87% of the study area) contributed 3 times more sediment volume than erosion from convergent areas (13% of the study area). However, the total normalized erosion depth (volume/area) was highest in convergent areas. From a detailed understanding of the spatial locations of erosion, we made inferences regarding the processes driving erosion. It appears that hillslope erosion is controlled by rain splash (for detachment) and overland flow (for transport and quasi-channelized erosion), with the sites of highest erosion corresponding to locations

  18. Underwater lidar system: design challenges and application in pollution detection

    Science.gov (United States)

    Gupta, Pradip; Sankolli, Swati; Chakraborty, A.

    2016-05-01

    The present remote sensing techniques have imposed limitations in the applications of LIDAR Technology. The fundamental sampling inadequacy of the remote sensing data obtained from satellites is that they cannot resolve in the third spatial dimension, the vertical. This limits our possibilities of measuring any vertical variability in the water column. Also the interaction between the physical and biological process in the oceans and their effects at subsequent depths cannot be modeled with present techniques. The idea behind this paper is to introduce underwater LIDAR measurement system by using a LIDAR mounted on an Autonomous Underwater Vehicle (AUV). The paper introduces working principles and design parameters for the LIDAR mounted AUV (AUV-LIDAR). Among several applications the papers discusses the possible use and advantages of AUV-LIDAR in water pollution detection through profiling of Dissolved Organic Matter (DOM) in water bodies.

  19. Spaceborne Lidar in the Study of Marine Systems.

    Science.gov (United States)

    Hostetler, Chris A; Behrenfeld, Michael J; Hu, Yongxiang; Hair, Johnathan W; Schulien, Jennifer A

    2018-01-03

    Satellite passive ocean color instruments have provided an unbroken ∼20-year record of global ocean plankton properties, but this measurement approach has inherent limitations in terms of spatial-temporal sampling and ability to resolve vertical structure within the water column. These limitations can be addressed by coupling ocean color data with measurements from a spaceborne lidar. Airborne lidars have been used for decades to study ocean subsurface properties, but recent breakthroughs have now demonstrated that plankton properties can be measured with a satellite lidar. The satellite lidar era in oceanography has arrived. Here, we present a review of the lidar technique, its applications in marine systems, a perspective on what can be accomplished in the near future with an ocean- and atmosphere-optimized satellite lidar, and a vision for a multiplatform virtual constellation of observational assets that would enable a three-dimensional reconstruction of global ocean ecosystems.

  20. Spaceborne Lidar in the Study of Marine Systems

    Science.gov (United States)

    Hostetler, Chris A.; Behrenfeld, Michael J.; Hu, Yongxiang; Hair, Johnathan W.; Schulien, Jennifer A.

    2018-01-01

    Satellite passive ocean color instruments have provided an unbroken ˜20-year record of global ocean plankton properties, but this measurement approach has inherent limitations in terms of spatial-temporal sampling and ability to resolve vertical structure within the water column. These limitations can be addressed by coupling ocean color data with measurements from a spaceborne lidar. Airborne lidars have been used for decades to study ocean subsurface properties, but recent breakthroughs have now demonstrated that plankton properties can be measured with a satellite lidar. The satellite lidar era in oceanography has arrived. Here, we present a review of the lidar technique, its applications in marine systems, a perspective on what can be accomplished in the near future with an ocean- and atmosphere-optimized satellite lidar, and a vision for a multiplatform virtual constellation of observational assets that would enable a three-dimensional reconstruction of global ocean ecosystems.

  1. Lidar and aircraft studies of deep Cirrus systems from the 1986 FIRE IFO

    Science.gov (United States)

    Sassen, Kenneth; Heymsfield, Andrew J.; Knight, Nancy C.

    1990-01-01

    Several NCAR King Air flight missions were conducted during the Wisconsin FIRE IFO experiment in support of the University of Utah polarization lidar observations of deep cirrus cloud systems at the Wausau ground site. Data collected from four cirrus systems are included in this analysis, including those of 22 and 28 October, and 1 and 2 November. Lidar data were generally obtained at 2 min intervals in the zenith direction over observation periods that ranged from approximately 4 to 10 h, bracketing the aircraft missions. The data were processed to yield height-time (HTI) displays of lidar linear depolarization ratio sigma and relative range-normalized return power P. King Air operations consisted of a combination of rapid profiling and Lagrangian spiral descents and stacked racetrack patterns in the vicinity of the field site. From the spiral descents are constructed vertical profiles of ice particle concentration N(sub i) and ice mass content IWC derived from PMS 2-D probe imagery and, when detected, FSSP cloud droplet concentration N(sub W) and liquid water content, LWC. Aircraft flight leg data are presented for the vertical velocity W and the same ice and water cloud content parameters. In addition, aerosol particle concentrations obtained with the ASAS probe are examined, and photographs of ice particles collected in-situ on oil-coated slides are presented to illustrate ice particle habit.

  2. The marbll experiment: towards a martian wind lidar

    Directory of Open Access Journals (Sweden)

    Määttänen Anni

    2018-01-01

    Full Text Available Operating a lidar on Mars would fulfill the need of accessing wind and aerosol profiles in the atmospheric boundary layer. This is the purpose of the MARs Boundary Layer Lidar (MARBLL instrument. We report recent developments of this compact direct-detection wind lidar designed to operate from the surface of Mars. A new laser source has been developed and an azimuthal scanning capability has been added. Preliminary results of a field campaign are presented.

  3. A cloud masking algorithm for EARLINET lidar systems

    Science.gov (United States)

    Binietoglou, Ioannis; Baars, Holger; D'Amico, Giuseppe; Nicolae, Doina

    2015-04-01

    Cloud masking is an important first step in any aerosol lidar processing chain as most data processing algorithms can only be applied on cloud free observations. Up to now, the selection of a cloud-free time interval for data processing is typically performed manually, and this is one of the outstanding problems for automatic processing of lidar data in networks such as EARLINET. In this contribution we present initial developments of a cloud masking algorithm that permits the selection of the appropriate time intervals for lidar data processing based on uncalibrated lidar signals. The algorithm is based on a signal normalization procedure using the range of observed values of lidar returns, designed to work with different lidar systems with minimal user input. This normalization procedure can be applied to measurement periods of only few hours, even if no suitable cloud-free interval exists, and thus can be used even when only a short period of lidar measurements is available. Clouds are detected based on a combination of criteria including the magnitude of the normalized lidar signal and time-space edge detection performed using the Sobel operator. In this way the algorithm avoids misclassification of strong aerosol layers as clouds. Cloud detection is performed using the highest available time and vertical resolution of the lidar signals, allowing the effective detection of low-level clouds (e.g. cumulus humilis). Special attention is given to suppress false cloud detection due to signal noise that can affect the algorithm's performance, especially during day-time. In this contribution we present the details of algorithm, the effect of lidar characteristics (space-time resolution, available wavelengths, signal-to-noise ratio) to detection performance, and highlight the current strengths and limitations of the algorithm using lidar scenes from different lidar systems in different locations across Europe.

  4. FOREST STEM VOLUME CALCULATION USING AIRBORNE LIDAR DATA

    Directory of Open Access Journals (Sweden)

    I. Büyüksalih

    2017-05-01

    Full Text Available Airborne LiDAR data have been collected for the city of Istanbul using Riegl laser scanner Q680i with 400 kHz and an average flight height of 600 m. The flight campaign was performed by a helicopter and covers an area of 5400 km2. According to a flight speed of 80 knot a point density of more than 16 points/m2 and a laser footprint size of 30 cm could be achieved. As a result of bundle adjustment, in total, approximately 17,000 LAS files with the file size of 500 m by 700 m have been generated for the whole city. The main object classes Ground, Building, Vegetation (medium, high were derived from these LAS files using the macros in Terrasolid software. The forest area under investigation is located northwest of the city of Istanbul, main tree species occurring in the test site are pine (pinus pinaster, oak (quercus and beech (fagus. In total, 120 LAS tiles covering the investigation area have been analysed using the software IMPACT of Joanneum Research Forschungsgesellschaft, Graz, Austria. First of all, the digital terrain model (DTM and the digital surface models (DSM were imported and converted into a raster file from the original laser point clouds with a spatial resolution of 50 cm. Then, a normalized digital surface model (nDSM was derived as the difference between DSM and the DTM. Tree top detection was performed by multi – resolution filter operations and tree crowns were segmented by a region growing algorithms develop specifically for this purpose. Breast Height Diameter (BHD was calculated on the base of tree height and crown areas derived from image segmentation applying allometric functions found in literature. The assessment of stem volume was then calculated as a function of tree height and BHD. A comparison of timber volume estimated from the LiDAR data and field plots measured by the Forest Department of Istanbul showed R2 of 0.46. The low correlation might arise either from the low quality of the field plots or

  5. LIDAR and atmosphere remote sensing [DST Space Science Initiatives

    CSIR Research Space (South Africa)

    Venkataraman, S

    2009-04-01

    Full Text Available Energy Source included in the measurement. Slide 2 © CSIR 2008 www.csir.co.za The observer can control the source Eg. Radar, Lidar, Sodar, Sonar etc. (b) Passive remote sensors. Energy source is not included in the measurement... Instrument Passive Slide 3 © CSIR 2008 www.csir.co.za Active LiDAR Principle • LIDAR (Light Detection and Ranging) • LiDAR employs a laser as a source of pulsed energy • Lasers are advantageous because – checkbld Monochromatic...

  6. Gluing for Raman lidar systems using the lamp mapping technique.

    Science.gov (United States)

    Walker, Monique; Venable, Demetrius; Whiteman, David N

    2014-12-20

    In the context of combined analog and photon counting (PC) data acquisition in a Lidar system, glue coefficients are defined as constants used for converting an analog signal into a virtual PC signal. The coefficients are typically calculated using Lidar profile data taken under clear, nighttime conditions since, in the presence of clouds or high solar background, it is difficult to obtain accurate glue coefficients from Lidar backscattered data. Here we introduce a new method in which we use the lamp mapping technique (LMT) to determine glue coefficients in a manner that does not require atmospheric profiles to be acquired and permits accurate glue coefficients to be calculated when adequate Lidar profile data are not available. The LMT involves scanning a halogen lamp over the aperture of a Lidar receiver telescope such that the optical efficiency of the entire detection system is characterized. The studies shown here involve two Raman lidar systems; the first from Howard University and the second from NASA/Goddard Space Flight Center. The glue coefficients determined using the LMT and the Lidar backscattered method agreed within 1.2% for the water vapor channel and within 2.5% for the nitrogen channel for both Lidar systems. We believe this to be the first instance of the use of laboratory techniques for determining the glue coefficients for Lidar data analysis.

  7. NASA ESTO Lidar Technologies Investment Strategy: 2016 Decadal Update

    Science.gov (United States)

    Valinia, Azita; Komar, George J.; Tratt, David M.; Lotshaw, William T.; Gaab, Kevin M.

    2017-01-01

    The NASA Earth Science Technology Office (ESTO) recently updated its investment strategy in the area of lidar technologies as it pertains to NASA's Earth Science measurement goals in the next decade. The last ESTO lidar strategy was documented in 2006. The current (2016) report assesses the state-of-the-art in lidar technologies a decade later. Lidar technology maturation in the past decade has been evaluated, and the ESTO investment strategy is updated and laid out in this report according to current NASA Earth science measurement needs and new emerging technologies.

  8. Large Scale Landform Mapping Using Lidar DEM

    Directory of Open Access Journals (Sweden)

    Türkay Gökgöz

    2015-08-01

    Full Text Available In this study, LIDAR DEM data was used to obtain a primary landform map in accordance with a well-known methodology. This primary landform map was generalized using the Focal Statistics tool (Majority, considering the minimum area condition in cartographic generalization in order to obtain landform maps at 1:1000 and 1:5000 scales. Both the primary and the generalized landform maps were verified visually with hillshaded DEM and an orthophoto. As a result, these maps provide satisfactory visuals of the landforms. In order to show the effect of generalization, the area of each landform in both the primary and the generalized maps was computed. Consequently, landform maps at large scales could be obtained with the proposed methodology, including generalization using LIDAR DEM.

  9. Measuring Oscillating Walking Paths with a LIDAR

    Directory of Open Access Journals (Sweden)

    Jordi Palacín

    2011-05-01

    Full Text Available This work describes the analysis of different walking paths registered using a Light Detection And Ranging (LIDAR laser range sensor in order to measure oscillating trajectories during unsupervised walking. The estimate of the gait and trajectory parameters were obtained with a terrestrial LIDAR placed 100 mm above the ground with the scanning plane parallel to the floor to measure the trajectory of the legs without attaching any markers or modifying the floor. Three different large walking experiments were performed to test the proposed measurement system with straight and oscillating trajectories. The main advantages of the proposed system are the possibility to measure several steps and obtain average gait parameters and the minimum infrastructure required. This measurement system enables the development of new ambulatory applications based on the analysis of the gait and the trajectory during a walk.

  10. Coaxial direct-detection lidar-system

    DEFF Research Database (Denmark)

    2014-01-01

    The invention relates to a coaxial direct-detection LIDAR system for measuring velocity, temperature and/or particulate density. The system comprises a laser source for emitting a laser light beam having a lasing center frequency along an emission path. The system further comprises an optical....... Finally, the system comprises a detector system arranged to receive the return signal from the optical delivery system, the detector system comprising a narrowband optical filter and a detector, the narrowband optical filter having a filter center frequency of a pass-band, wherein the center lasing...... frequency and/or the center filter frequency may be scanned. The invention further relates to an aircraft airspeed measurement device, and a wind turbine airspeed measurement device comprising the LIDAR system....

  11. Quantitative study of tectonic geomorphology along Haiyuan fault based on airborne LiDAR

    Science.gov (United States)

    Chen, Tao; Zhang, Pei Zhen; Liu, Jing; Li, Chuan You; Ren, Zhi Kun; Hudnut, Kenneth W.

    2014-01-01

    High-precision and high-resolution topography are the fundamental data for active fault research. Light detection and ranging (LiDAR) presents a new approach to build detailed digital elevation models effectively. We take the Haiyuan fault in Gansu Province as an example of how LiDAR data may be used to improve the study of active faults and the risk assessment of related hazards. In the eastern segment of the Haiyuan fault, the Shaomayin site has been comprehensively investigated in previous research because of its exemplary tectonic topographic features. Based on unprecedented LiDAR data, the horizontal and vertical coseismic offsets at the Shaomayin site are described. The measured horizontal value is about 8.6 m, and the vertical value is about 0.8 m. Using prior dating ages sampled from the same location, we estimate the horizontal slip rate as 4.0 ± 1.0 mm/a with high confidence and define that the lower bound of the vertical slip rate is 0.4 ± 0.1 mm/a since the Holocene. LiDAR data can repeat the measurements of field work on quantifying offsets of tectonic landform features quite well. The offset landforms are visualized on an office computer workstation easily, and specialized software may be used to obtain displacement quantitatively. By combining precious chronological results, the fundamental link between fault activity and large earthquakes is better recognized, as well as the potential risk for future earthquake hazards.

  12. The LIDAR Thomson scattering diagnostic on JET

    International Nuclear Information System (INIS)

    Salzmann, H.; Gadd, A.

    1989-01-01

    By combining the time-of-flight or LIDAR principle with a Thomson backscatter diagnostic, spatial profiles of the electron temperature and density can be measured with a single set of detectors for all spatial points. This approach considerably simplifies the collection optics required for measuring a spatial profile. The system is described and examples of measurements are given and compared with the results of other diagnostics. (author)

  13. Doppler Lidar Wind Value-Added Product

    Energy Technology Data Exchange (ETDEWEB)

    Newsom, R. K. [DOE ARM Climate Research Facility, Washington, DC (United States); Sivaraman, C. [DOE ARM Climate Research Facility, Washington, DC (United States); Shippert, T. R. [DOE ARM Climate Research Facility, Washington, DC (United States); Riihimaki, L. D. [DOE ARM Climate Research Facility, Washington, DC (United States)

    2015-07-01

    Wind speed and direction, together with pressure, temperature, and relative humidity, are the most fundamental atmospheric state parameters. Accurate measurement of these parameters is crucial for numerical weather prediction. Vertically resolved wind measurements in the atmospheric boundary layer are particularly important for modeling pollutant and aerosol transport. Raw data from a scanning coherent Doppler lidar system can be processed to generate accurate height-resolved measurements of wind speed and direction in the atmospheric boundary layer.

  14. Contrasting Patterns of Damage and Recovery in Logged Amazon Forests From Small Footprint LiDAR Data

    Science.gov (United States)

    Morton, D. C.; Keller, M.; Cook, B. D.; Hunter, Maria; Sales, Marcio; Spinelli, L.; Victoria, D.; Andersen, H.-E.; Saleska, S.

    2012-01-01

    Tropical forests ecosystems respond dynamically to climate variability and disturbances on time scales of minutes to millennia. To date, our knowledge of disturbance and recovery processes in tropical forests is derived almost exclusively from networks of forest inventory plots. These plots typically sample small areas (less than or equal to 1 ha) in conservation units that are protected from logging and fire. Amazon forests with frequent disturbances from human activity remain under-studied. Ongoing negotiations on REDD+ (Reducing Emissions from Deforestation and Forest Degradation plus enhancing forest carbon stocks) have placed additional emphasis on identifying degraded forests and quantifying changing carbon stocks in both degraded and intact tropical forests. We evaluated patterns of forest disturbance and recovery at four -1000 ha sites in the Brazilian Amazon using small footprint LiDAR data and coincident field measurements. Large area coverage with airborne LiDAR data in 2011-2012 included logged and unmanaged areas in Cotriguacu (Mato Grosso), Fiona do Jamari (Rondonia), and Floresta Estadual do Antimary (Acre), and unmanaged forest within Reserva Ducke (Amazonas). Logging infrastructure (skid trails, log decks, and roads) was identified using LiDAR returns from understory vegetation and validated based on field data. At each logged site, canopy gaps from logging activity and LiDAR metrics of canopy heights were used to quantify differences in forest structure between logged and unlogged areas. Contrasting patterns of harvesting operations and canopy damages at the three logged sites reflect different levels of pre-harvest planning (i.e., informal logging compared to state or national logging concessions), harvest intensity, and site conditions. Finally, we used multi-temporal LiDAR data from two sites, Reserva Ducke (2009, 2012) and Antimary (2010, 2011), to evaluate gap phase dynamics in unmanaged forest areas. The rates and patterns of canopy gap

  15. Atmospheric lidar: legislative, scientific and technological aspects; Lidar atmosferico. Aspetti legislativi, scientifici e tecnologici

    Energy Technology Data Exchange (ETDEWEB)

    Barbini, R.; Colao, F.; Fiorani, L.; Palucci, A. [ENEA, Divisione Fisica Applicata, Centro Ricerche Frascati, Frascati, RM (Italy)

    2000-07-01

    The Atmospheric Lidar is one of the systems of the Mobile Laboratory of Laser Remote Sensing under development at the ENEA Research Center of Frascati. This technical report addresses the legislative, scientific and technological aspects that are the basis for the identification of the requirements, the definition of the architecture and the fixation of the specifications of the Atmospheric Lidar. The problems of air pollution are introduced in section 2. A summary of the Italian laws on that topic is then given. Section 4 provides a survey of the atmospheric measurements that can be achieved with the lidar. The sensitivity in the monitoring of pollutants is discussed in section 5. The other systems of the Mobile Laboratory of Laser Remote Sensing are shortly described in section 6. The last section is devoted to conclusions and perspectives. [Italian] Il lidar atmosferico e' uno dei sistemi del Laboratorio Mobile di Telerilevamento Laser in corso di realizzazione presso il Centro Ricerche di Frascati dell'ENEA. Questo rapporto tecnico discute gli aspetti legislativi, scientifici, tecnologici che sono alla base dell'individuazione dei requisiti, della definizione dell'architettura e della fissazione delle specifiche del Lidar atmosferico. La problematica dell'inquinamento dell'aria e' introdotta nella sezione 2. Segue un riassunto della legislazione italiana su tale tematica. La sezione 4 offre una panoramica delle misure atmosferiche realizzabili con il Lidar. La sensibilita' nel monitoraggio di inquinanti e' discussa nella sezione 5. Gli altri sistemi del Laboratorio Mobile di Telerilevamento Laser sono descritti brevemente nella sezione 6. L'ultima sezione e' dedicata alle conclusioni e alle prospettive.

  16. Detection of large above-ground biomass variability in lowland forest ecosystems by airborne LiDAR

    Directory of Open Access Journals (Sweden)

    J. Jubanski

    2013-06-01

    Full Text Available Quantification of tropical forest above-ground biomass (AGB over large areas as input for Reduced Emissions from Deforestation and forest Degradation (REDD+ projects and climate change models is challenging. This is the first study which attempts to estimate AGB and its variability across large areas of tropical lowland forests in Central Kalimantan (Indonesia through correlating airborne light detection and ranging (LiDAR to forest inventory data. Two LiDAR height metrics were analysed, and regression models could be improved through the use of LiDAR point densities as input (R2 = 0.88; n = 52. Surveying with a LiDAR point density per square metre of about 4 resulted in the best cost / benefit ratio. We estimated AGB for 600 km of LiDAR tracks and showed that there exists a considerable variability of up to 140% within the same forest type due to varying environmental conditions. Impact from logging operations and the associated AGB losses dating back more than 10 yr could be assessed by LiDAR but not by multispectral satellite imagery. Comparison with a Landsat classification for a 1 million ha study area where AGB values were based on site-specific field inventory data, regional literature estimates, and default values by the Intergovernmental Panel on Climate Change (IPCC showed an overestimation of 43%, 102%, and 137%, respectively. The results show that AGB overestimation may lead to wrong greenhouse gas (GHG emission estimates due to deforestation in climate models. For REDD+ projects this leads to inaccurate carbon stock estimates and consequently to significantly wrong REDD+ based compensation payments.

  17. Relative drifts and stability of satellite and ground-based stratospheric ozone profiles at NDACC lidar stations

    Directory of Open Access Journals (Sweden)

    P. J. Nair

    2012-06-01

    Full Text Available The long-term evolution of stratospheric ozone at different stations in the low and mid-latitudes is investigated. The analysis is performed by comparing the collocated profiles of ozone lidars, at the northern mid-latitudes (Meteorological Observatory Hohenpeißenberg, Haute-Provence Observatory, Tsukuba and Table Mountain Facility, tropics (Mauna Loa Observatory and southern mid-latitudes (Lauder, with ozonesondes and space-borne sensors (SBUV(/2, SAGE II, HALOE, UARS MLS and Aura MLS, extracted around the stations. Relative differences are calculated to find biases and temporal drifts in the measurements. All measurement techniques show their best agreement with respect to the lidar at 20–40 km, where the differences and drifts are generally within ±5% and ±0.5% yr−1, respectively, at most stations. In addition, the stability of the long-term ozone observations (lidar, SBUV(/2, SAGE II and HALOE is evaluated by the cross-comparison of each data set. In general, all lidars and SBUV(/2 exhibit near-zero drifts and the comparison between SAGE II and HALOE shows larger, but insignificant drifts. The RMS of the drifts of lidar and SBUV(/2 is 0.22 and 0.27% yr−1, respectively at 20–40 km. The average drifts of the long-term data sets, derived from various comparisons, are less than ±0.3% yr−1 in the 20–40 km altitude at all stations. A combined time series of the relative differences between SAGE II, HALOE and Aura MLS with respect to lidar data at six sites is constructed, to obtain long-term data sets lasting up to 27 years. The relative drifts derived from these combined data are very small, within ±0.2% yr−1.

  18. Adaptive Data Processing Technique for Lidar-Assisted Control to Bridge the Gap between Lidar Systems and Wind Turbines: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Schlipf, David; Raach, Steffen; Haizmann, Florian; Cheng, Po Wen; Fleming, Paul; Scholbrock, Andrew, Krishnamurthy, Raghu; Boquet, Mathieu

    2015-12-14

    This paper presents first steps toward an adaptive lidar data processing technique crucial for lidar-assisted control in wind turbines. The prediction time and the quality of the wind preview from lidar measurements depend on several factors and are not constant. If the data processing is not continually adjusted, the benefit of lidar-assisted control cannot be fully exploited, or can even result in harmful control action. An online analysis of the lidar and turbine data are necessary to continually reassess the prediction time and lidar data quality. In this work, a structured process to develop an analysis tool for the prediction time and a new hardware setup for lidar-assisted control are presented. The tool consists of an online estimation of the rotor effective wind speed from lidar and turbine data and the implementation of an online cross correlation to determine the time shift between both signals. Further, initial results from an ongoing campaign in which this system was employed for providing lidar preview for feed-forward pitch control are presented.

  19. Lidar signal-to-noise ratio improvements: Considerations and techniques

    Science.gov (United States)

    Hassebo, Yasser Y.

    The primary objective of this study is to improve lidar signal-to-noise ratio (SNR) and hence extend attainable lidar ranges through reduction of the sky background noise (BGP), which dominates other sources of noise in daytime operations. This is particularly important for Raman lidar techniques where the Raman backscattered signal of interest is relatively weak compared with the elastic backscatter lidars. Two approaches for reduction of sky background noise are considered: (1) Improvements in lidar SNR by optimization of the design of the lidar receiver were examined by a series of simulations. This part of the research concentrated on biaxial lidar systems, where overlap between laser beam and receiver field of view (FOV) is an important aspect of noise considerations. The first optimized design evolved is a wedge shaped aperture. While this design has the virtue of greatly reducing background light, it is difficult to implement practically, requiring both changes in area and position with lidar range. A second more practical approach, which preserves some of the advantages of the wedge design, was also evolved. This uses a smaller area circular aperture optimally located in the image plane for desired ranges. Simulated numerical results for a biaxial lidar have shown that the best receiver parameters selection is one using a small circular aperture (field stop) with a small telescope focal length f, to ensure the minimum FOV that accepts all return signals over the entire lidar range while at the same time minimizing detected BGP and hence maximizing lidar SNR and attainable lidar ranges. The improvement in lidar SNR was up to 18%. (2) A polarization selection technique was implemented to reduce sky background signal for linearly polarized monostatic elastic backscatter lidar measurements. The technique takes advantage of naturally occurring polarization properties in scattered sky light, and then ensures that both the lidar transmitter and receiver track and

  20. Turbulence estimation from a continuous-wave scanning lidar (SpinnerLidar)

    DEFF Research Database (Denmark)

    Barnhoorn, J.G.; Sjöholm, Mikael; Mikkelsen, Torben Krogh

    2017-01-01

    out, and 2) the mixing of velocity covariances from other components into the line-of-sight variance measurements. However, turbulence measurements based on upwind horizontal rotor plane scanning of the line-of-sight variance measurements combined with ensemble-averaged Doppler spectra width...... deviations averaged over 10-min sampling periods are compared. Lidar variances are inherently more prone to noise which always yields a positive bias. The 5.3 % higher turbulence level measured by the SpinnerLidar relative to the cup anemometer may equally well be attributed to truncation of turbulent...

  1. Validation and deployment of the first Lidar based weather observation network in New York State: The NYS MesoNet Project

    Directory of Open Access Journals (Sweden)

    Thobois L.

    2018-01-01

    This paper will describe the New York State Mesonet that is being deployed in the state of New York, USA. It is composed of 126 stations including 17 profiler sites. These sites will acquire continuous upper air observations through the combination of WINDCUBE Lidars and microwave radiometers. These stations will provide temperature, relative humidity & “3D” wind profile measurements through and above the planetary boundary layer (PBL and will retrieve derived atmospheric quantities such as the PBL height, cloud base, momentum fluxes, and aerosol & cloud optical properties. The different modes and configurations that will be used for the Lidars are discussed. The performances in terms of data availability and wind accuracy and precision are evaluated. Several profiles with specific wind and aerosol features are presented to illustrate the benefits of the use of Coherent Doppler Lidars to monitor accurately the PBL.

  2. Complex Terrain and Wind Lidars

    DEFF Research Database (Denmark)

    Bingöl, Ferhat

    software WAsP Engineering 2.0 and was well predicted except for some sectors where the terrain is particularly steep. Subsequently, two experiments were performed in forested areas; where the measurements are recorded at a location deep-in forest and at the forest edge. Both sites were modelled with flow...... edge, LINCOM model was used by allocating a slope half-in half out of the forest based on the suggestions of previous studies. The optimum slope angle was reported as 17º. Thus, a suggestion was made to use WAsP Engineering 2.0 for forest edge modelling with known limitations and the applied method...

  3. Comparing Individual Tree Segmentation Based on High Resolution Multispectral Image and Lidar Data

    Science.gov (United States)

    Xiao, P.; Kelly, M.; Guo, Q.

    2014-12-01

    This study compares the use of high-resolution multispectral WorldView images and high density Lidar data for individual tree segmentation. The application focuses on coniferous and deciduous forests in the Sierra Nevada Mountains. The tree objects are obtained in two ways: a hybrid region-merging segmentation method with multispectral images, and a top-down and bottom-up region-growing method with Lidar data. The hybrid region-merging method is used to segment individual tree from multispectral images. It integrates the advantages of global-oriented and local-oriented region-merging strategies into a unified framework. The globally most-similar pair of regions is used to determine the starting point of a growing region. The merging iterations are constrained within the local vicinity, thus the segmentation is accelerated and can reflect the local context. The top-down region-growing method is adopted in coniferous forest to delineate individual tree from Lidar data. It exploits the spacing between the tops of trees to identify and group points into a single tree based on simple rules of proximity and likely tree shape. The bottom-up region-growing method based on the intensity and 3D structure of Lidar data is applied in deciduous forest. It segments tree trunks based on the intensity and topological relationships of the points, and then allocate other points to exact tree crowns according to distance. The accuracies for each method are evaluated with field survey data in several test sites, covering dense and sparse canopy. Three types of segmentation results are produced: true positive represents a correctly segmented individual tree, false negative represents a tree that is not detected and assigned to a nearby tree, and false positive represents that a point or pixel cluster is segmented as a tree that does not in fact exist. They respectively represent correct-, under-, and over-segmentation. Three types of index are compared for segmenting individual tree

  4. Fusion of multi-temporal Airborne Snow Observatory (ASO) lidar data for mountainous vegetation ecosystems studies.

    Science.gov (United States)

    Ferraz, A.; Painter, T. H.; Saatchi, S.; Bormann, K. J.

    2016-12-01

    Fusion of multi-temporal Airborne Snow Observatory (ASO) lidar data for mountainous vegetation ecosystems studies The NASA Jet Propulsion Laboratory developed the Airborne Snow Observatory (ASO), a coupled scanning lidar system and imaging spectrometer, to quantify the spatial distribution of snow volume and dynamics over mountains watersheds (Painter et al., 2015). To do this, ASO weekly over-flights mountainous areas during snowfall and snowmelt seasons. In addition, there are additional flights in snow-off conditions to calculate Digital Terrain Models (DTM). In this study, we focus on the reliability of ASO lidar data to characterize the 3D forest vegetation structure. The density of a single point cloud acquisition is of nearly 1 pt/m2, which is not optimal to properly characterize vegetation. However, ASO covers a given study site up to 14 times a year that enables computing a high-resolution point cloud by merging single acquisitions. In this study, we present a method to automatically register ASO multi-temporal lidar 3D point clouds. Although flight specifications do not change between acquisition dates, lidar datasets might have significant planimetric shifts due to inaccuracies in platform trajectory estimation introduced by the GPS system and drifts of the IMU. There are a large number of methodologies that address the problem of 3D data registration (Gressin et al., 2013). Briefly, they look for common primitive features in both datasets such as buildings corners, structures like electric poles, DTM breaklines or deformations. However, they are not suited for our experiment. First, single acquisition point clouds have low density that makes the extraction of primitive features difficult. Second, the landscape significantly changes between flights due to snowfall and snowmelt. Therefore, we developed a method to automatically register point clouds using tree apexes as keypoints because they are features that are supposed to experience little change

  5. On the detectability of internal waves by an imaging lidar

    NARCIS (Netherlands)

    Magalhaes, J.M.; da Silva, J.C.B.; Batista, M.; Gostiaux, L.; Gerkema, T.; New, A.L.; Jeans, D.R.G.

    2013-01-01

    The first results of a multisensor airborne survey conducted off the western Iberian Coast are presented (including visible, lidar, and infrared imagery) and reveal the presence of internal solitary waves (ISWs) propagating into the nearshore region. For the first time, two-dimensional lidar imagery

  6. 2013 Suwannee River Water Management District Lidar: Greenville (FL)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Light Detection and Ranging (LiDAR) dataset is a survey of Suwannee River G12PD00242 1.0 Meter LiDAR Survey Area 3, Classified Point Cloud, in north-central...

  7. 2014 Suwannee River Water Management District Lidar: Cooks Hammock (FL)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Light Detection and Ranging (LiDAR) dataset is a survey of the Suwannee River G14PD00206 0.7 Meter LiDAR Survey in central Florida and encompasses 571 square...

  8. An evaluation of the WindEye wind lidar

    DEFF Research Database (Denmark)

    Dellwik, Ebba; Sjöholm, Mikael; Mann, Jakob

    Prevision of the wind field by remote sensing wind lidars has the potential to improve the performance of wind turbines. The functionality of a WindEye lidar developed by Windar Photonics A/S (Denmark) for the wind energy market was tested in a two months long field experiment. The WindEye sensor...... with a high accuracy during the whole campaign....

  9. Coherent Lidar Turbulence Measurement for Gust Load Alleviation

    Science.gov (United States)

    Bogue, Rodney K.; Ehernberger, L. J.; Soreide, David; Bagley, Hal

    1996-01-01

    Atmospheric turbulence adversely affects operation of commercial and military aircraft and is a design constraint. The airplane structure must be designed to survive the loads imposed by turbulence. Reducing these loads allows the airplane structure to be lighter, a substantial advantage for a commercial airplane. Gust alleviation systems based on accelerometers mounted in the airplane can reduce the maximum gust loads by a small fraction. These systems still represent an economic advantage. The ability to reduce the gust load increases tremendously if the turbulent gust can be measured before the airplane encounters it. A lidar system can make measurements of turbulent gusts ahead of the airplane, and the NASA Airborne Coherent Lidar for Advanced In-Flight Measurements (ACLAIM) program is developing such a lidar. The ACLAIM program is intended to develop a prototype lidar system for use in feasibility testing of gust load alleviation systems and other airborne lidar applications, to define applications of lidar with the potential for improving airplane performance, and to determine the feasibility and benefits of these applications. This paper gives an overview of the ACLAIM program, describes the lidar architecture for a gust alleviation system, and describes the prototype ACLAIM lidar system.

  10. 2013 Suwannee River Water Management District Lidar: Bell (FL)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Light Detection and Ranging (LiDAR) dataset is a survey of Suwannee River G13PD00141 1.0 Meter LiDAR Survey Area 4, Classified Point Cloud, in north-central...

  11. Alternative method for determining the constant offset in lidar signal

    Science.gov (United States)

    Vladimir A. Kovalev; Cyle Wold; Alexander Petkov; Wei Min Hao

    2009-01-01

    We present an alternative method for determining the total offset in lidar signal created by a daytime background-illumination component and electrical or digital offset. Unlike existing techniques, here the signal square-range-correction procedure is initially performed using the total signal recorded by lidar, without subtraction of the offset component. While...

  12. 2013 Suwannee River Water Management District Lidar: Mayo (FL)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Light Detection and Ranging (LiDAR) dataset is a survey of Suwannee River G12PD00242 1.0 Meter LiDAR Survey Area 4, Classified Point Cloud, in north-central...

  13. Analysis of inflow parameters using LiDARs

    NARCIS (Netherlands)

    Giyanani, A.H.; Bierbooms, W.A.A.M.; Van Bussel, G.J.W.

    2014-01-01

    Remote sensing of the atmospheric variables with the use of LiDAR is a relatively new technique for wind resource assessment and oncoming wind prediction in wind energy. The validation of LiDAR measurements and comparisons with other sensing elements thus, is of high importance for further

  14. 2006 OSIP OGRIP: Upland Counties LiDAR Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 2006 OSIP digital LiDAR data was collected during the months of March and May (leaf-off conditions). The LiDAR covers the entire land area of the northern tier...

  15. Mechanical design of a lidar system for space applications - LITE

    Science.gov (United States)

    Crockett, Sharon K.

    1990-01-01

    The Lidar In-Space Technology Experiment (LITE) is a Shuttle experiment that will demonstrate the first use of a lidar system in space. Its design process must take into account not only the system design but also the unique design requirements for spaceborne experiment.

  16. Turbulence characterization from a forward-looking nacelle lidar

    DEFF Research Database (Denmark)

    Peña, Alfredo; Mann, Jakob; Dimitrov, Nikolay Krasimirov

    2017-01-01

    of lidars were installed on the nacelle of a wind turbine. Comparison of the lidar-based along-wind unfiltered variances with those from a cup anemometer installed on a meteorological mast close to the turbine shows a bias of just 2 %. The ratios of the unfiltered and filtered radial velocity variances...

  17. 2013 USGS-NRCS Lidar: Maine (Cumberland, Kennebec and York)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: NRCS Maine 0.7M NPS LIDAR LiDAR Data Acquisition and Processing Production Task USGS Contract No. G10PC00057 Task Order No. G13PD00954 Woolpert Order No....

  18. LiDAR utility for natural resource managers

    Science.gov (United States)

    Andrew Thomas Hudak; Jeffrey Scott Evans; Alistair Mattthew Stuart. Smith

    2009-01-01

    Applications of LiDAR remote sensing are exploding, while moving from the research to the operational realm. Increasingly, natural resource managers are recognizing the tremendous utility of LiDAR-derived information to make improved decisions. This review provides a cross-section of studies, many recent, that demonstrate the relevance of LiDAR across a suite of...

  19. Toepassingen van de LIDAR-meettechniek in atmosferisch onderzoek

    NARCIS (Netherlands)

    Salemink; H.W.M.; Maanen; E.A.van*

    1985-01-01

    De ontwikkeling van de menglaaghoogte kan zeer wel met lidar gevolgd worden. De resultaten komen overeen met die verkregen met een klassieke acdar-opstelling. Het nadeel van acdar is echter dat deze de menglaaghoogte tot maximaal 600 m kan volgen, terwijl lidar een bereik van 3 km ruimschoots

  20. Dickinson County, MI LIDAR_LAS_1.2

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME:(NRCS) Dickinson County, MI LIDAR LiDAR Data Acquisition and Processing Production Task USGS Contract No. G10PC00057 Task Order No. G12PD00721 Woolpert...

  1. High resolution wind turbine wake measurements with a scanning lidar

    DEFF Research Database (Denmark)

    Herges, T. G.; Maniaci, D. C.; Naughton, B. T.

    2017-01-01

    High-resolution lidar wake measurements are part of an ongoing field campaign being conducted at the Scaled Wind Farm Technology facility by Sandia National Laboratories and the National Renewable Energy Laboratory using a customized scanning lidar from the Technical University of Denmark. One...

  2. 2013 Suwannee River Water Management District Lidar: Obrien (FL)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Light Detection and Ranging (LiDAR) dataset is a survey of Suwannee River G13PD00141 1.0 Meter LiDAR Survey Area 1, Classified Point Cloud, in north-central...

  3. Wind speed errors for LIDARs and SODARs in complex terrain

    International Nuclear Information System (INIS)

    Bradley, S

    2008-01-01

    All commercial LIDARs and SODARs are monostatic and hence sample distributed volumes to construct wind vector components. We use an analytic potential flow model to estimate errors arising for a range of LIDAR and SODAR configurations on hills and escarpments. Wind speed errors peak at a height relevant to wind turbines and can be typically 20%

  4. Wind speed errors for LIDARs and SODARs in complex terrain

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, S [Physics Department, The University of Auckland, Private Bag 92019, Auckland (New Zealand) and School of Computing, Science and Engineering, University of Salford, M5 4WT (United Kingdom)], E-mail: s.bradley@auckland.ac.nz

    2008-05-01

    All commercial LIDARs and SODARs are monostatic and hence sample distributed volumes to construct wind vector components. We use an analytic potential flow model to estimate errors arising for a range of LIDAR and SODAR configurations on hills and escarpments. Wind speed errors peak at a height relevant to wind turbines and can be typically 20%.

  5. 2013 Suwannee River Water Management District (SRWMD) Lidar: Ichetucknee (FL)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Light Detection and Ranging (LiDAR) dataset is a survey of the Suwannee River G12PD00242 1.0 Meter LiDAR Survey area 2 in north-central Florida and encompasses...

  6. Suwannee River Water Management District Lidar: Falmouth (FL)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Light Detection and Ranging (LiDAR) dataset is a survey of the Suwannee River G12PD00242 1.0 Meter LiDAR Survey area 5 in north-central Florida and encompasses...

  7. 2013 Suwannee River Water Management District Lidar: Ocean Pond (FL)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Light Detection and Ranging (LiDAR) dataset is a survey of Suwannee River G13PD00141 1.0 Meter LiDAR Survey Area 3, Classified Point Cloud, in north-central...

  8. Constraining lidar stand-alone retrievals with lunar photometry measurements

    Science.gov (United States)

    Ortiz-Amezcua, Pablo; Luis Guerrero-Rascado, Juan; Antonio Benavent-Oltra, Jose; Román, Roberto; Böckmann, Christine; Alados-Arboledas, Lucas

    2018-04-01

    This study combines atmospheric optical information measured with lidar and nocturnal photometers in order to find configurations that allow for the retrieval of particle microphysical properties without "3+2" lidar setups. It has been carried out using data measured at the EARLINET Granada station during the experimental campaign SLOPE in the framework of ACTRIS-2 project.

  9. MPLNET V3 Cloud and Planetary Boundary Layer Detection

    Science.gov (United States)

    Lewis, Jasper R.; Welton, Ellsworth J.; Campbell, James R.; Haftings, Phillip C.

    2016-01-01

    The NASA Micropulse Lidar Network Version 3 algorithms for planetary boundary layer and cloud detection are described and differences relative to the previous Version 2 algorithms are highlighted. A year of data from the Goddard Space Flight Center site in Greenbelt, MD consisting of diurnal and seasonal trends is used to demonstrate the results. Both the planetary boundary layer and cloud algorithms show significant improvement of the previous version.

  10. Doppler lidar sensor for precision navigation in GPS-deprived environment

    Science.gov (United States)

    Amzajerdian, F.; Pierrottet, D. F.; Hines, G. D.; Petway, L. B.; Barnes, B. W.

    2013-05-01

    Landing mission concepts that are being developed for exploration of solar system bodies are increasingly ambitious in their implementations and objectives. Most of these missions require accurate position and velocity data during their descent phase in order to ensure safe, soft landing at the pre-designated sites. Data from the vehicle's Inertial Measurement Unit will not be sufficient due to significant drift error after extended travel time in space. Therefore, an onboard sensor is required to provide the necessary data for landing in the GPS-deprived environment of space. For this reason, NASA Langley Research Center has been developing an advanced Doppler lidar sensor capable of providing accurate and reliable data suitable for operation in the highly constrained environment of space. The Doppler lidar transmits three laser beams in different directions toward the ground. The signal from each beam provides the platform velocity and range to the ground along the laser line-of-sight (LOS). The six LOS measurements are then combined in order to determine the three components of the vehicle velocity vector, and to accurately measure altitude and attitude angles relative to the local ground. These measurements are used by an autonomous Guidance, Navigation, and Control system to accurately navigate the vehicle from a few kilometers above the ground to the designated location and to execute a gentle touchdown. A prototype version of our lidar sensor has been completed for a closed-loop demonstration onboard a rocket-powered terrestrial free-flyer vehicle.

  11. Ground level and Lidar monitoring of volcanic dust and dust from Patagonia

    Science.gov (United States)

    Otero, L. A.; Losno, R.; Salvador, J. O.; Journet, E.; Qu, Z.; Triquet, S.; Monna, F.; Balkanski, Y.; Bulnes, D.; Ristori, P. R.; Quel, E. J.

    2013-05-01

    A combined approach including ground level aerosol sampling, lidar and sunphotometer measurements is used to monitor suspended particles in the atmosphere at several sites in Patagonia. Motivated by the Puyehue volcanic eruption in June 2011 two aerosol monitoring stations with several passive and active instruments were installed in Bariloche and Comodoro Rivadavia. The main goal which is to monitor ground lifted and transported ashes and dust involving danger to civil aviation, is achieved by measuring continuously aerosol concentration at ground level and aerosol vertical distribution using lidar. In addition, starting from December 2011, continuous series of weekly accumulated aerosol concentrations at Rio Gallegos are being measured to study the impact of Patagonian dust over the open ocean on phytoplankton primary productivity and CO2 removal. These measurements are going to be coupled with LIDAR monitoring and a dust optical response models to test if aerosol extrapolation can be done from the ground to the top of the layer. Laboratory chemical analysis of the aerosols will include elemental composition, solubilisation kinetic and mineralogical determination. Expected deliverables for this study is the estimation of the amount of dust exported from Patagonia towards the South Atlantic, its chemical properties, including bioavailability simulation, from model and comparison to experimental measurements.

  12. Towards lidar-based mapping of tree age at the Arctic forest tundra ecotone.

    Science.gov (United States)

    Jensen, J.; Maguire, A.; Oelkers, R.; Andreu-Hayles, L.; Boelman, N.; D'Arrigo, R.; Griffin, K. L.; Jennewein, J. S.; Hiers, E.; Meddens, A. J.; Russell, M.; Vierling, L. A.; Eitel, J.

    2017-12-01

    Climate change may cause spatial shifts in the forest-tundra ecotone (FTE). To improve our ability to study these spatial shifts, information on tree demography along the FTE is needed. The objective of this study was to assess the suitability of lidar derived tree heights as a surrogate for tree age. We calculated individual tree age from 48 tree cores collected at basal height from white spruce (Picea glauca) within the FTE in northern Alaska. Tree height was obtained from terrestrial lidar scans (= 3 m), yielding strong predictive relationships between height and age (R2 = 0.86, RMSE 12.21 years, and R2 = 0.93, RMSE = 25.16 years, respectively). The slope coefficient for small and large tree models (16.83 and 12.98 years/m, respectively) indicate that small trees grow 1.3 times faster than large trees at these FTE study sites. Although a strong, predictive relationship between age and height is uncommon in light-limited forest environments, our findings suggest that the sparseness of trees within the FTE may explain the strong tree height-age relationships found herein. Further analysis of 36 additional tree cores recently collected within the FTE near Inuvik, Canada will be performed. Our preliminary analysis suggests that lidar derived tree height could be a reliable proxy for tree age at the FTE, thereby establishing a new technique for scaling tree structure and demographics across larger portions of this sensitive ecotone.

  13. Algorithm for Extracting Digital Terrain Models under Forest Canopy from Airborne LiDAR Data

    Directory of Open Access Journals (Sweden)

    Almasi S. Maguya

    2014-07-01

    Full Text Available Extracting digital elevationmodels (DTMs from LiDAR data under forest canopy is a challenging task. This is because the forest canopy tends to block a portion of the LiDAR pulses from reaching the ground, hence introducing gaps in the data. This paper presents an algorithm for DTM extraction from LiDAR data under forest canopy. The algorithm copes with the challenge of low data density by generating a series of coarse DTMs by using the few ground points available and using trend surfaces to interpolate missing elevation values in the vicinity of the available points. This process generates a cloud of ground points from which the final DTM is generated. The algorithm has been compared to two other algorithms proposed in the literature in three different test sites with varying degrees of difficulty. Results show that the algorithm presented in this paper is more tolerant to low data density compared to the other two algorithms. The results further show that with decreasing point density, the differences between the three algorithms dramatically increased from about 0.5m to over 10m.

  14. Study of African Dust with Multi-Wavelength Raman Lidar During "Shadow" Campaign in Senegal

    Science.gov (United States)

    Veselovskii, Igor; Goloub, Philippe; Podvin, Thierry; Bovchaliuk, Valentyn; Tanre, Didier; Derimian, Yevgeny; Korenskiy, Mikhail; Dubovik, Oleg

    2016-06-01

    West Africa and the adjacent oceanic regions are very important locations for studying dust properties and their influence on weather and climate. The SHADOW (Study of SaHAran Dust Over West Africa) campaign is performing a multi-scale and multi-laboratory study of aerosol properties and dynamics using a set of in situ and remote sensing instruments at an observation site located at IRD (Institute for Research and Development) Center, Mbour, Senegal (14°N, 17°W). In this paper, we present the results of lidar measurements performed during the first phase of SHADOW which occurred in March-April, 2015. The multiwavelength Mie-Raman lidar acquired 3β+2α+1δ measurements during this period. This set of measurements has permitted particle intensive properties such as extinction and backscattering Ångström exponents (BAE) for 355/532 nm wavelengths corresponding lidar ratios and depolarization ratio at 532 nm to be determined. The backscattering Ångström exponent during the dust episodes decreased to ~-0.7, while the extinction Ångström exponent though being negative, was greater than -0.2. Low values of BAE can likely be explained by an increase in the imaginary part of the dust refractive index at 355 nm compared to 532 nm.

  15. 2004 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Portland, Oregon

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The all returns ASCII files contain the X,Y,Z values of all the LiDAR returns collected during the survey mission. In addition each return also has a time stamp,...

  16. Methods from Information Extraction from LIDAR Intensity Data and Multispectral LIDAR Technology

    Science.gov (United States)

    Scaioni, M.; Höfle, B.; Baungarten Kersting, A. P.; Barazzetti, L.; Previtali, M.; Wujanz, D.

    2018-04-01

    LiDAR is a consolidated technology for topographic mapping and 3D reconstruction, which is implemented in several platforms On the other hand, the exploitation of the geometric information has been coupled by the use of laser intensity, which may provide additional data for multiple purposes. This option has been emphasized by the availability of sensors working on different wavelength, thus able to provide additional information for classification of surfaces and objects. Several applications ofmonochromatic and multi-spectral LiDAR data have been already developed in different fields: geosciences, agriculture, forestry, building and cultural heritage. The use of intensity data to extract measures of point cloud quality has been also developed. The paper would like to give an overview on the state-of-the-art of these techniques, and to present the modern technologies for the acquisition of multispectral LiDAR data. In addition, the ISPRS WG III/5 on `Information Extraction from LiDAR Intensity Data' has collected and made available a few open data sets to support scholars to do research on this field. This service is presented and data sets delivered so far as are described.

  17. METHODS FROM INFORMATION EXTRACTION FROM LIDAR INTENSITY DATA AND MULTISPECTRAL LIDAR TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    M. Scaioni

    2018-04-01

    Full Text Available LiDAR is a consolidated technology for topographic mapping and 3D reconstruction, which is implemented in several platforms On the other hand, the exploitation of the geometric information has been coupled by the use of laser intensity, which may provide additional data for multiple purposes. This option has been emphasized by the availability of sensors working on different wavelength, thus able to provide additional information for classification of surfaces and objects. Several applications ofmonochromatic and multi-spectral LiDAR data have been already developed in different fields: geosciences, agriculture, forestry, building and cultural heritage. The use of intensity data to extract measures of point cloud quality has been also developed. The paper would like to give an overview on the state-of-the-art of these techniques, and to present the modern technologies for the acquisition of multispectral LiDAR data. In addition, the ISPRS WG III/5 on ‘Information Extraction from LiDAR Intensity Data’ has collected and made available a few open data sets to support scholars to do research on this field. This service is presented and data sets delivered so far as are described.

  18. A user friendly Lidar system based on LabVIEW

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Mats; Weibring, P.

    1996-09-01

    Mobile differential absorption lidar (DIAL) systems have been used for the last two decades. The lidar group in Lund has performed many DIAL measurements with a mobile lidar system which was first described in 1987. This report describes how that system was updated with the graphical programming language LabVIEW in order to get a user friendly system. The software controls the lidar system and analyses measurement data. The measurement results are shown as maps of species concentration. New electronics to support the new lidar program have also been installed. The report describes how all supporting electronics and the program work. A user manual for the new program is also given. 19 refs, 79 figs, 23 charts

  19. Power curve measurement with a nacelle mounted lidar

    DEFF Research Database (Denmark)

    Wagner, Rozenn; Friis Pedersen, Troels; Courtney, Michael

    2014-01-01

    is tested. A pulsed lidar prototype, measuring horizontally, was installed on the nacelle of a multi-megawatt wind turbine. A met mast with a top-mounted cup anemometer standing at two rotor diameters in front of the turbine was used as a reference. After a data-filtering step, the comparison of the 10 min......Nacelle-based lidars are an attractive alternative to conventional mast base reference wind instrumentation where the erection of a mast is expensive, for example offshore. In this paper, the use of this new technology for the specific application of wind turbine power performance measurement...... in wind speed measurements. A lower scatter in the power curve was observed for the lidar than for the mast. Since the lidar follows the turbine nacelle as it yaws, it always measures upwind. The wind measured by the lidar therefore shows a higher correlation with the turbine power fluctuations than...

  20. Optical Backscattering Measured by Airborne Lidar and Underwater Glider

    Directory of Open Access Journals (Sweden)

    James H. Churnside

    2017-04-01

    Full Text Available The optical backscattering from particles in the ocean is an important quantity that has been measured by remote sensing techniques and in situ instruments. In this paper, we compare estimates of this quantity from airborne lidar with those from an in situ instrument on an underwater glider. Both of these technologies allow much denser sampling of backscatter profiles than traditional ship surveys. We found a moderate correlation (R = 0.28, p < 10−5, with differences that are partially explained by spatial and temporal sampling mismatches, variability in particle composition, and lidar retrieval errors. The data suggest that there are two different regimes with different scattering properties. For backscattering coefficients below about 0.001 m−1, the lidar values were generally greater than the glider values. For larger values, the lidar was generally lower than the glider. Overall, the results are promising and suggest that airborne lidar and gliders provide comparable and complementary information on optical particulate backscattering.

  1. Wind Ressources in Complex Terrain investigated with Synchronized Lidar Measurements

    Science.gov (United States)

    Mann, J.; Menke, R.; Vasiljevic, N.

    2017-12-01

    The Perdigao experiment was performed by a number of European and American universities in Portugal 2017, and it is probably the largest field campaign focussing on wind energy ressources in complex terrain ever conducted. 186 sonic anemometers on 50 masts, 20 scanning wind lidars and a host of other instruments were deployed. The experiment is a part of an effort to make a new European wind atlas. In this presentation we investigate whether scanning the wind speed over ridges in this complex terrain with multiple Doppler lidars can lead to an efficient mapping of the wind resources at relevant positions. We do that by having pairs of Doppler lidars scanning 80 m above the ridges in Perdigao. We compare wind resources obtained from the lidars and from the mast-mounted sonic anemometers at 80 m on two 100 m masts, one on each of the two ridges. In addition, the scanning lidar measurements are also compared to profiling lidars on the ridges. We take into account the fact that the profiling lidars may be biased due to the curvature of the streamlines over the instrument, see Bingol et al, Meteorolog. Z. vol. 18, pp. 189-195 (2009). We also investigate the impact of interruptions of the lidar measurements on the estimated wind resource. We calculate the relative differences of wind along the ridge from the lidar measurements and compare those to the same obtained from various micro-scale models. A particular subject investigated is how stability affects the wind resources. We often observe internal gravity waves with the scanning lidars during the night and we quantify how these affect the relative wind speed on the ridges.

  2. Evaluating lidar point densities for effective estimation of aboveground biomass

    Science.gov (United States)

    Wu, Zhuoting; Dye, Dennis G.; Stoker, Jason M.; Vogel, John M.; Velasco, Miguel G.; Middleton, Barry R.

    2016-01-01

    The U.S. Geological Survey (USGS) 3D Elevation Program (3DEP) was recently established to provide airborne lidar data coverage on a national scale. As part of a broader research effort of the USGS to develop an effective remote sensing-based methodology for the creation of an operational biomass Essential Climate Variable (Biomass ECV) data product, we evaluated the performance of airborne lidar data at various pulse densities against Landsat 8 satellite imagery in estimating above ground biomass for forests and woodlands in a study area in east-central Arizona, U.S. High point density airborne lidar data, were randomly sampled to produce five lidar datasets with reduced densities ranging from 0.5 to 8 point(s)/m2, corresponding to the point density range of 3DEP to provide national lidar coverage over time. Lidar-derived aboveground biomass estimate errors showed an overall decreasing trend as lidar point density increased from 0.5 to 8 points/m2. Landsat 8-based aboveground biomass estimates produced errors larger than the lowest lidar point density of 0.5 point/m2, and therefore Landsat 8 observations alone were ineffective relative to airborne lidar for generating a Biomass ECV product, at least for the forest and woodland vegetation types of the Southwestern U.S. While a national Biomass ECV product with optimal accuracy could potentially be achieved with 3DEP data at 8 points/m2, our results indicate that even lower density lidar data could be sufficient to provide a national Biomass ECV product with accuracies significantly higher than that from Landsat observations alone.

  3. Comprehensive wind correction for a Rayleigh Doppler lidar from atmospheric temperature and pressure influences and Mie contamination

    International Nuclear Information System (INIS)

    Shangguan Ming-Jia; Xia Hai-Yun; Dou Xian-Kang; Wang Chong; Qiu Jia-Wei; Zhang Yun-Peng; Shu Zhi-Feng; Xue Xiang-Hui

    2015-01-01

    A correction considering the effects of atmospheric temperature, pressure, and Mie contamination must be performed for wind retrieval from a Rayleigh Doppler lidar (RDL), since the so-called Rayleigh response is directly related to the convolution of the optical transmission of the frequency discriminator and the Rayleigh–Brillouin spectrum of the molecular backscattering. Thus, real-time and on-site profiles of atmospheric pressure, temperature, and aerosols should be provided as inputs to the wind retrieval. Firstly, temperature profiles under 35 km and above the altitude are retrieved, respectively, from a high spectral resolution lidar (HSRL) and a Rayleigh integration lidar (RIL) incorporating to the RDL. Secondly, the pressure profile is taken from the European Center for Medium range Weather Forecast (ECMWF) analysis, while radiosonde data are not available. Thirdly, the Klett–Fernald algorithms are adopted to estimate the Mie and Rayleigh components in the atmospheric backscattering. After that, the backscattering ratio is finally determined in a nonlinear fitting of the transmission of the atmospheric backscattering through the Fabry–Perot interferometer (FPI) to a proposed model. In the validation experiments, wind profiles from the lidar show good agreement with the radiosonde in the overlapping altitude. Finally, a continuous wind observation shows the stability of the correction scheme. (paper)

  4. A COMPARITIVE STUDY USING GEOMETRIC AND VERTICAL PROFILE FEATURES DERIVED FROM AIRBORNE LIDAR FOR CLASSIFYING TREE GENERA

    Directory of Open Access Journals (Sweden)

    C. Ko

    2012-07-01

    Full Text Available We present a comparative study between two different approaches for tree genera classification using descriptors derived from tree geometry and those derived from the vertical profile analysis of LiDAR point data. The different methods provide two perspectives for processing LiDAR point clouds for tree genera identification. The geometric perspective analyzes individual tree crowns in relation to valuable information related to characteristics of clusters and line segments derived within crowns and overall tree shapes to highlight the spatial distribution of LiDAR points within the crown. Conversely, analyzing vertical profiles retrieves information about the point distributions with respect to height percentiles; this perspective emphasizes of the importance that point distributions at specific heights express, accommodating for the decreased point density with respect to depth of canopy penetration by LiDAR pulses. The targeted species include white birch, maple, oak, poplar, white pine and jack pine at a study site northeast of Sault Ste. Marie, Ontario, Canada.

  5. Sensitivity analysis of nacelle lidar free stream wind speed measurements to wind-induction reconstruction model and lidar range configuration

    DEFF Research Database (Denmark)

    Svensson, Elin; Borraccino, Antoine; Meyer Forsting, Alexander Raul

    The sensitivity of nacelle lidar wind speed measurements to wind-induction models and lidar range configurations is studied using experimental data from the Nørrekær Enge (NKE) measurement campaign and simulated lidar data from Reynold-Averaged Navier Stokes (RANS) aerodynamic computational fluid...... the ZDM was configured to measure at five distances. From the configured distances, a large number of range configurations were created and systematically tested to determine the sensitivity of the reconstructed wind speeds to the number of ranges, minimum range and maximum range in the range......) of the fitting residuals. The results demonstrate that it is not possible to use RANS CFD simulated lidar data to determine optimal range configurations for real-time nacelle lidars due to their perfect (unrealistic) representation of the simulated flow field. The recommended range configurations are therefore...

  6. CHARACTERIZING URBAN VOLUMETRY USING LIDAR DATA

    Directory of Open Access Journals (Sweden)

    T. Santos

    2013-05-01

    Most common metrics are based on area (2D measurements. These include indicators like impervious area per capita or surface occupied by green areas, having usually as primary source a spectral image obtained through a satellite or airborne camera. More recently, laser scanning data has become available for large-scale applications. Such sensors acquire altimetric information and are used to produce Digital Surface Models (DSM. In this context, LiDAR data available for the city is explored along with demographic information, and a framework to produce volumetric (3D urban indexes is proposed, and measures like Built Volume per capita, Volumetric Density and Volumetric Homogeneity are computed.

  7. In-situ, sunphotometer and Raman lidar observations of aerosol transport events in the western Mediterranean during the June 2013 ChArMEx campaign

    Science.gov (United States)

    Totems, Julien; Sicard, Michael; Bertolin, Santi; Boytard, Mai-Lan; Chazette, Patrick; Comeron, Adolfo; Dulac, Francois; Hassanzadeh, Sahar; Lange, Diego; Marnas, Fabien; Munoz, Constantino; Shang, Xiaoxia

    2014-05-01

    We present a preliminary analysis of aerosol observations performed in June 2013 in the western Mediterranean at two stations set up in Barcelona and Menorca (Spain) in the framework of the ChArMEx (Chemistry Aerosol Mediterranean Experiment) project. The Barcelona station was equipped with the following fixed instruments belonging to the Universitat Politècnica de Catalunya (UPC): an AERONET (Aerosol Robotic Network) sun-photometer, an MPL (Micro Pulse Lidar) lidar and the UPC multi-wavelength lidar. The MPL lidar works at 532 nm and has a depolarization channel, while the UPC lidar works at 355, 532 and 1064 nm, and also includes two N2- (at 387 and 607 nm) and one H2O-Raman (at 407 nm) channels. The MPL system works continuously 24 hour/day. The UPC system was operated on alert in coordination with the research aircrafts plans involved in the campaign. In Cap d'en Font, Menorca, the mobile laboratory of the Laboratoire des Sciences du Climat et de l'Environnement hosted an automated (AERONET) and a manual (Microtops) 5-lambda sunphotometer, a 3-lambda nephelometer, a 7-lambda aethalometer, as well as the LSCE Water vapor Aerosol LIdar (WALI). This mini Raman lidar, first developed and validated for the HyMEX (Hydrological cycle in the Mediterranean eXperiment) campaign in 2012, works at 355 nm for eye safety and is designed with a short overlap distance (the lower troposphere. It includes depolarization, N2- and H2O-Raman channels. H2O observations have been calibrated on-site by different methods and show good agreement with balloon measurements. Observations at Cap d'en Font were quasi-continuous from June 10th to July 3rd, 2013. The lidar data at both stations helped direct the research aircrafts and balloon launches to interesting plumes of particles in real time for in-situ measurements. Among some light pollution background from the European continent, a typical Saharan dust event and an unusual American dust/biomass burning event are highlighted in our

  8. Remote Sensing of Vegetation Species Diversity: The Utility of Integrated Airborne Hyperspectral and Lidar Data

    Science.gov (United States)

    Krause, Keith Stuart

    The change, reduction, or extinction of species is a major issue currently facing the Earth. Efforts are underway to measure, monitor, and protect habitats that contain high species diversity. Remote sensing technology shows extreme value for monitoring species diversity by mapping ecosystems and using those land cover maps or other derived data as proxies to species number and distribution. The National Ecological Observatory Network (NEON) Airborne Observation Platform (AOP) consists of remote sensing instruments such as an imaging spectrometer, a full-waveform lidar, and a high-resolution color camera. AOP collected data over the Ordway-Swisher Biological Station (OSBS) in May 2014. A majority of the OSBS site is covered by the Sandhill ecosystem, which contains a very high diversity of vegetation species and is a native habitat for several threatened fauna species. The research presented here investigates ways to analyze the AOP data to map ecosystems at the OSBS site. The research attempts to leverage the high spatial resolution data and study the variability of the data within a ground plot scale along with integrating data from the different sensors. Mathematical features are derived from the data and brought into a decision tree classification algorithm (rpart), in order to create an ecosystem map for the site. The hyperspectral and lidar features serve as proxies for chemical, functional, and structural differences in the vegetation types for each of the ecosystems. K-folds cross validation shows a training accuracy of 91%, a validation accuracy of 78%, and a 66% accuracy using independent ground validation. The results presented here represent an important contribution to utilizing integrated hyperspectral and lidar remote sensing data for ecosystem mapping, by relating the spatial variability of the data within a ground plot scale to a collection of vegetation types that make up a given ecosystem.

  9. Comparison of small-footprint discrete return and full waveform airborne lidar data for estimating multiple forest variables

    OpenAIRE

    Sumnall, Matthew J.; Hill, Ross A.; Hinsley, Shelley A.

    2016-01-01

    The quantification of forest ecosystems is important for a variety of purposes, including the assessment of wildlife habitat, nutrient cycles, timber yield and fire propagation. This research assesses the estimation of forest structure, composition and deadwood variables from small-footprint airborne lidar data, both discrete return (DR) and full waveform (FW), acquired under leaf-on and leaf-off conditions. The field site, in the New Forest, UK, includes managed plantation and ancient, se...

  10. Theoretical analysis and simulation of the influence of self-bunching effects and longitudinal space charge effects on the propagation of keV electron bunch produced by a novel S-band Micro-Pulse electron Gun

    Science.gov (United States)

    Zhao, Jifei; Lu, Xiangyang; Zhou, Kui; Yang, Ziqin; Yang, Deyu; Luo, Xing; Tan, Weiwei; Yang, Yujia

    2016-06-01

    As an important electron source, Micro-Pulse electron Gun (MPG) which is qualified for producing high average current, short pulse, low emittance electron bunches steadily holds promise to use as an electron source of Coherent Smith-Purcell Radiation (CSPR), Free Electron Laser (FEL). The stable output of S-band MPG has been achieved in many labs. To establish reliable foundation for the future application of it, the propagation of picosecond electron bunch produced by MPG should be studied in detail. In this article, the MPG which was working on the rising stage of total effective Secondary Electron Yield (SEY) curve was introduced. The self-bunching mechanism was discussed in depth both in the multipacting amplifying state and the steady working state. The bunch length broadening induced by the longitudinal space-charge (SC) effects was investigated by different theoretical models in different regions. The 2D PIC codes MAGIC and beam dynamic codes TraceWin simulations were also performed in the propagation. The result shows an excellent agreement between the simulation and the theoretical analysis for bunch length evolution.

  11. Theoretical analysis and simulation of the influence of self-bunching effects and longitudinal space charge effects on the propagation of keV electron bunch produced by a novel S-band Micro-Pulse electron Gun

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jifei; Lu, Xiangyang, E-mail: xylu@pku.edu.cn; Yang, Ziqin; Yang, Deyu; Tan, Weiwei; Yang, Yujia [Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing, 100871 (China); Zhou, Kui; Luo, Xing [Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang 621900 (China)

    2016-06-15

    As an important electron source, Micro-Pulse electron Gun (MPG) which is qualified for producing high average current, short pulse, low emittance electron bunches steadily holds promise to use as an electron source of Coherent Smith-Purcell Radiation (CSPR), Free Electron Laser (FEL). The stable output of S-band MPG has been achieved in many labs. To establish reliable foundation for the future application of it, the propagation of picosecond electron bunch produced by MPG should be studied in detail. In this article, the MPG which was working on the rising stage of total effective Secondary Electron Yield (SEY) curve was introduced. The self-bunching mechanism was discussed in depth both in the multipacting amplifying state and the steady working state. The bunch length broadening induced by the longitudinal space-charge (SC) effects was investigated by different theoretical models in different regions. The 2D PIC codes MAGIC and beam dynamic codes TraceWin simulations were also performed in the propagation. The result shows an excellent agreement between the simulation and the theoretical analysis for bunch length evolution.

  12. Theoretical analysis and simulation of the influence of self-bunching effects and longitudinal space charge effects on the propagation of keV electron bunch produced by a novel S-band Micro-Pulse electron Gun

    Directory of Open Access Journals (Sweden)

    Jifei Zhao

    2016-06-01

    Full Text Available As an important electron source, Micro-Pulse electron Gun (MPG which is qualified for producing high average current, short pulse, low emittance electron bunches steadily holds promise to use as an electron source of Coherent Smith-Purcell Radiation (CSPR, Free Electron Laser (FEL. The stable output of S-band MPG has been achieved in many labs. To establish reliable foundation for the future application of it, the propagation of picosecond electron bunch produced by MPG should be studied in detail. In this article, the MPG which was working on the rising stage of total effective Secondary Electron Yield (SEY curve was introduced. The self-bunching mechanism was discussed in depth both in the multipacting amplifying state and the steady working state. The bunch length broadening induced by the longitudinal space-charge (SC effects was investigated by different theoretical models in different regions. The 2D PIC codes MAGIC and beam dynamic codes TraceWin simulations were also performed in the propagation. The result shows an excellent agreement between the simulation and the theoretical analysis for bunch length evolution.

  13. Quantifying TOLNet Ozone Lidar Accuracy During the 2014 DISCOVER-AQ and FRAPPE Campaigns

    Science.gov (United States)

    Wang, Lihua; Newchurch, Michael J.; Alvarez, Raul J., II; Berkoff, Timothy A.; Brown, Steven S.; Carrion, William; De Young, Russell J.; Johnson, Bryan J.; Ganoe, Rene; Gronoff, Guillaume; hide

    2017-01-01

    The Tropospheric Ozone Lidar Network (TOLNet) is a unique network of lidar systems that measure high-resolution atmospheric profiles of ozone. The accurate characterization of these lidars is necessary to determine the uniformity of the network calibration. From July to August 2014, three lidars, the TROPospheric OZone (TROPOZ) lidar, the Tunable Optical Profiler for Aerosol and oZone (TOPAZ) lidar, and the Langley Mobile Ozone Lidar (LMOL), of TOLNet participated in the Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) mission and the Front Range Air Pollution and Photochemistry Experiment (FRAPPA) to measure ozone variations from the boundary layer to the top of the troposphere. This study presents the analysis of the intercomparison between the TROPOZ, TOPAZ, and LMOL lidars, along with comparisons between the lidars and other in situ ozone instruments including ozonesondes and a P-3B airborne chemiluminescence sensor. The TOLNet lidars measured vertical ozone structures with an accuracy generally better than +/-15 % within the troposphere. Larger differences occur at some individual altitudes in both the near-field and far-field range of the lidar systems, largely as expected. In terms of column average, the TOLNet lidars measured ozone with an accuracy better than +/-5 % for both the intercomparison between the lidars and between the lidars and other instruments. These results indicate that these three TOLNet lidars are suitable for use in air quality, satellite validation, and ozone modeling efforts.

  14. Derivation of Sky-View Factors from LIDAR Data

    Science.gov (United States)

    Kidd, Christopher; Chapman, Lee

    2013-01-01

    The use of Lidar (Light Detection and Ranging), an active light-emitting instrument, is becoming increasingly common for a range of potential applications. Its ability to provide fine resolution spatial and vertical resolution elevation data makes it ideal for a wide range of studies. This paper demonstrates the capability of Lidar data to measure sky view factors (SVF). The Lidar data is used to generate a spatial map of SVFs which are then compared against photographically-derived SVF at selected point locations. At each location three near-surface elevations measurements were taken and compared with collocated Lidar-derived estimated. It was found that there was generally good agreement between the two methodologies, although with decreasing SVF the Lidar-derived technique tended to overestimate the SVF: this can be attributed in part to the spatial resolution of the Lidar sampling. Nevertheless, airborne Lidar systems can map sky view factors over a large area easily, improving the utility of such data in atmospheric and meteorological models.

  15. Object Classification Using Airborne Multispectral LiDAR Data

    Directory of Open Access Journals (Sweden)

    PAN Suoyan

    2018-02-01

    Full Text Available Airborne multispectral LiDAR system,which obtains surface geometry and spectral data of objects,simultaneously,has become a fast effective,large-scale spatial data acquisition method.Multispectral LiDAR data are characteristics of completeness and consistency of spectrum and spatial geometric information.Support vector machine (SVM,a machine learning method,is capable of classifying objects based on small samples.Therefore,by means of SVM,this paper performs land cover classification using multispectral LiDAR data. First,all independent point cloud with different wavelengths are merged into a single point cloud,where each pixel contains the three-wavelength spectral information.Next,the merged point cloud is converted into range and intensity images.Finally,land-cover classification is performed by means of SVM.All experiments were conducted on the Optech Titan multispectral LiDAR data,containing three individual point cloud collected by 532 nm,1024 nm,and 1550 nm laser beams.Experimental results demonstrate that ①compared to traditional single-wavelength LiDAR data,multispectral LiDAR data provide a promising solution to land use and land cover applications;②SVM is a feasible method for land cover classification of multispectral LiDAR data.

  16. Telescope aperture optimization for spacebased coherent wind lidar

    Science.gov (United States)

    Ge, Xian-ying; Zhu, Jun; Cao, Qipeng; Zhang, Yinchao; Yin, Huan; Dong, Xiaojing; Wang, Chao; Zhang, Yongchao; Zhang, Ning

    2015-08-01

    Many studies have indicated that the optimum measurement approach for winds from space is a pulsed coherent wind lidar, which is an active remote sensing tool with the characteristics that high spatial and temporal resolutions, real-time detection, high mobility, facilitated control and so on. Because of the significant eye safety, efficiency, size, and lifetime advantage, 2μm wavelength solid-state laser lidar systems have attracted much attention in spacebased wind lidar plans. In this paper, the theory of coherent detection is presented and a 2μm wavelength solid-state laser lidar system is introduced, then the ideal aperture is calculated from signal-to-noise(SNR) view at orbit 400km. However, considering real application, even if the lidar hardware is perfectly aligned, the directional jitter of laser beam, the attitude change of the lidar in the long round trip time of the light from the atmosphere and other factors can bring misalignment angle. So the influence of misalignment angle is considered and calculated, and the optimum telescope diameter(0.45m) is obtained as the misalignment angle is 4 μrad. By the analysis of the optimum aperture required for spacebased coherent wind lidar system, we try to present the design guidance for the telescope.

  17. Wind turbine control applications of turbine-mounted LIDAR

    International Nuclear Information System (INIS)

    Bossanyi, E A; Kumar, A; Hugues-Salas, O

    2014-01-01

    In recent years there has been much interest in the possible use of LIDAR systems for improving the performance of wind turbine controllers, by providing preview information about the approaching wind field. Various potential benefits have been suggested, and experimental measurements have sometimes been used to claim surprising gains in performance. This paper reports on an independent study which has used detailed analytical methods for two main purposes: firstly to try to evaluate the likely benefits of LIDAR-assisted control objectively, and secondly to provide advice to LIDAR manufacturers about the characteristics of LIDAR systems which are most likely to be of value for this application. Many different LIDAR configurations were compared: as a general conclusion, systems should be able to sample at least 10 points every second, reasonably distributed around the swept area, and allowing a look-ahead time of a few seconds. An important conclusion is that the main benefit of the LIDAR will be to enhance of collective pitch control to reduce thrust-related fatigue loads; there is some indication that extreme loads can also be reduced, but this depends on other considerations which are discussed in the paper. LIDAR-assisted individual pitch control, optimal C p tracking and yaw control were also investigated, but the benefits over conventional methods are less clear

  18. Uncovering archaeological landscapes at Angkor using lidar.

    Science.gov (United States)

    Evans, Damian H; Fletcher, Roland J; Pottier, Christophe; Chevance, Jean-Baptiste; Soutif, Dominique; Tan, Boun Suy; Im, Sokrithy; Ea, Darith; Tin, Tina; Kim, Samnang; Cromarty, Christopher; De Greef, Stéphane; Hanus, Kasper; Bâty, Pierre; Kuszinger, Robert; Shimoda, Ichita; Boornazian, Glenn

    2013-07-30

    Previous archaeological mapping work on the successive medieval capitals of the Khmer Empire located at Angkor, in northwest Cambodia (∼9th to 15th centuries in the Common Era, C.E.), has identified it as the largest settlement complex of the preindustrial world, and yet crucial areas have remained unmapped, in particular the ceremonial centers and their surroundings, where dense forest obscures the traces of the civilization that typically remain in evidence in surface topography. Here we describe the use of airborne laser scanning (lidar) technology to create high-precision digital elevation models of the ground surface beneath the vegetation cover. We identify an entire, previously undocumented, formally planned urban landscape into which the major temples such as Angkor Wat were integrated. Beyond these newly identified urban landscapes, the lidar data reveal anthropogenic changes to the landscape on a vast scale and lend further weight to an emerging consensus that infrastructural complexity, unsustainable modes of subsistence, and climate variation were crucial factors in the decline of the classical Khmer civilization.

  19. New laser design for NIR lidar applications

    Science.gov (United States)

    Vogelmann, H.; Trickl, T.; Perfahl, M.; Biggel, S.

    2018-04-01

    Recently, we quantified the very high spatio-temporal short term variability of tropospheric water vapor in a three dimensional study [1]. From a technical point of view this also depicted the general requirement of short integration times for recording water-vapor profiles with lidar. For this purpose, the only suitable technique is the differential absorption lidar (DIAL) working in the near-infrared (NIR) spectral region. The laser emission of most water vapor DIAL systems is generated by Ti:sapphire or alexandrite lasers. The water vapor absorption band at 817 nm is predominated for the use of Ti:sapphire. We present a new concept of transversely pumping in a Ti:Sapphire amplification stage as well as a compact laser design for the generation of single mode NIR pulses with two different DIAL wavelengths inside a single resonator. This laser concept allows for high output power due to repetitions rates up to 100Hz or even more. It is, because of its compactness, also suitable for mobile applications.

  20. Raman lidar characterization using a reference lamp

    Science.gov (United States)

    Landulfo, Eduardo; da Costa, Renata F.; Rodrigues, Patricia F.; da Silva Lopes, Fábio J.

    2014-10-01

    The determination of the amount of water vapor in the atmosphere using lidar is a calibration dependent technique. Different collocated instruments are used for this purpose, like radiossoundings and microwave radiometers. When there are no collocated instruments available, an independente lamp mapping calibration technique can be used. Aiming to stabilish an independ technique for the calibration of the six channels Nd-YAG Raman lidar system located at the Center for Lasers and Applications (CLA), S˜ao Paulo, Brazil, an optical characterization of the system was first performed using a reference tungsten lamp. This characterization is useful to identify any possible distortions in the interference filters, telescope mirror and stray light contamination. In this paper we show three lamp mapping caracterizations (01/16/2014, 01/22/2014, 04/09/2014). The first day is used to demostrate how the tecnique is useful to detect stray light, the second one how it is sensible to the position of the filters and the third one demostrates a well optimized optical system.

  1. Importance of Raman Lidar Aerosol Extinction Measurements for Aerosol-Cloud Interaction Studies

    Directory of Open Access Journals (Sweden)

    Han Zaw

    2016-01-01

    Full Text Available Using a UV Raman Lidar for aerosol extinction, and combining Microwave Radiometer derived Liquid Water Path (LWP with Multifilter Rotating Shadowband Radiometer derived Cloud Optical depth, to get cloud effective radius (Reff, we observe under certain specialized conditions, clear signatures of the Twomey Aerosol Indirect effect on cloud droplet properties which are consistent with the theoretical bounds. We also show that the measurement is very sensitive to how far the aerosol layer is from the cloud base and demonstrate that surface PM25 is far less useful. Measurements from both the DOE ARM site and new results at CCNY are presented.

  2. New lidar challenges for gas hazard management in industrial environments

    Science.gov (United States)

    Cézard, Nicolas; Liméry, Anasthase; Bertrand, Johan; Le Méhauté, Simon; Benoit, Philippe; Fleury, Didier; Goular, Didier; Planchat, Christophe; Valla, Matthieu; Augère, Béatrice; Dolfi-Bouteyre, Agnès.

    2017-10-01

    The capability of Lidars to perform range-resolved gas profiles makes them an appealing choice for many applications. In order to address new remote sensing challenges, arising from industrial contexts, Onera currently develops two lidar systems, one Raman and one DIAL. On the Raman side, a high spatial-resolution multi-channel Raman Lidar is developed in partnership with the French National Radioactive Waste Management Agency (Andra). This development aims at enabling future monitoring of hydrogen gas and water vapor profiles inside disposal cells containing radioactive wastes. We report on the development and first tests of a three-channel Raman Lidar (H2, H2O, N2) designed to address this issue. Simultaneous hydrogen and water vapor profiles have been successfully performed along a 5m-long gas cell with 1m resolution at a distance of 85 m. On the DIAL side, a new instrumental concept is being explored and developed in partnership with Total E and P. The objective is to perform methane plume monitoring and flux assessment in the vicinity of industrials plants or platforms. For flux assessment, both gas concentration and air speed must be profiled by lidar. Therefore, we started developing a bi-function, all-fiber, coherent DIAL/Doppler Lidar. The first challenge was to design and build an appropriate fiber laser source. The achieved demonstrator delivers 200 W peak power, polarized, spectrally narrow (<15 MHz), 110 ns pulses of light out of a monomode fiber at 1645 nm. It fulfills the requirements for a future implementation in a bi-function Dial/Doppler lidar with km-range expectation. We report on the laser and lidar architecture, and on first lidar tests at 1645 nm.

  3. 2012-2013 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Hoh River Watershed, Washington (Deliveries 1 and 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. (WSI) collected Light Detection and Ranging (LiDAR) data on the Hoh River watershed survey area for the Puget Sound LiDAR Consortium and the...

  4. Practical model for the calculation of multiply scattered lidar returns

    International Nuclear Information System (INIS)

    Eloranta, E.W.

    1998-01-01

    An equation to predict the intensity of the multiply scattered lidar return is presented. Both the scattering cross section and the scattering phase function can be specified as a function of range. This equation applies when the cloud particles are larger than the lidar wavelength. This approximation considers photon trajectories with multiple small-angle forward-scattering events and one large-angle scattering that directs the photon back toward the receiver. Comparisons with Monte Carlo simulations, exact double-scatter calculations, and lidar data demonstrate that this model provides accurate results. copyright 1998 Optical Society of America

  5. Airborne lidar detection of an underwater thermal vent

    Science.gov (United States)

    Roddewig, Michael R.; Churnside, James H.; Shaw, Joseph A.

    2017-07-01

    We report the lidar detection of an underwater feature that appears to be a thermal vent in Yellowstone Lake, Yellowstone National Park, USA, with the Montana State University Fish Lidar. The location of the detected vent was 30 m from the closest vent identified in a United States Geological Survey of Yellowstone Lake in 2008. A second possible vent is also presented, and the appearance of both vents in the lidar data is compared to descriptions of underwater thermal vents in Yellowstone Lake from the geological literature.

  6. TENSOR MODELING BASED FOR AIRBORNE LiDAR DATA CLASSIFICATION

    Directory of Open Access Journals (Sweden)

    N. Li

    2016-06-01

    Full Text Available Feature selection and description is a key factor in classification of Earth observation data. In this paper a classification method based on tensor decomposition is proposed. First, multiple features are extracted from raw LiDAR point cloud, and raster LiDAR images are derived by accumulating features or the “raw” data attributes. Then, the feature rasters of LiDAR data are stored as a tensor, and tensor decomposition is used to select component features. This tensor representation could keep the initial spatial structure and insure the consideration of the neighborhood. Based on a small number of component features a k nearest neighborhood classification is applied.

  7. Saver.net lidar network in southern South America

    Directory of Open Access Journals (Sweden)

    Ristori Pablo

    2018-01-01

    Full Text Available The South American Environmental Risk Management Network (SAVER-Net is an instrumentation network, mainly composed by lidars, to provide real-time information for atmospheric hazards and risk management purposes in South America. This lidar network have been developed since 2012 and all its sampling points are expected to be fully implemented by 2017. This paper describes the network’s status and configuration, the data acquisition and processing scheme (protocols and data levels, as well as some aspects of the scientific networking in Latin American Lidar Network (LALINET. Similarly, the paper lays out future plans on the operation and integration to major international collaborative efforts.

  8. Saver.net lidar network in southern South America

    Science.gov (United States)

    Ristori, Pablo; Otero, Lidia; Jin, Yoshitaka; Barja, Boris; Shimizu, Atsushi; Barbero, Albane; Salvador, Jacobo; Bali, Juan Lucas; Herrera, Milagros; Etala, Paula; Acquesta, Alejandro; Quel, Eduardo; Sugimoto, Nobuo; Mizuno, Akira

    2018-04-01

    The South American Environmental Risk Management Network (SAVER-Net) is an instrumentation network, mainly composed by lidars, to provide real-time information for atmospheric hazards and risk management purposes in South America. This lidar network have been developed since 2012 and all its sampling points are expected to be fully implemented by 2017. This paper describes the network's status and configuration, the data acquisition and processing scheme (protocols and data levels), as well as some aspects of the scientific networking in Latin American Lidar Network (LALINET). Similarly, the paper lays out future plans on the operation and integration to major international collaborative efforts.

  9. Meteorology and lidar data from the URAHFREP field trials

    DEFF Research Database (Denmark)

    Ott, Søren; Ejsing Jørgensen, Hans

    2002-01-01

    to the HF release. The instrumentation included various types of HF sensors, thermocouple arrays, a fully instrumented release rig, a passive smokemachine, a meteorological mast and a lidar backscatter system. This report deals exclusively with the meteorological data and the lidar data. The trials cover...... a range meteorological conditions. These include neutral conditions with relatively highwindspeed and low humidity as well as unstable conditions with low windspeed and high humidity, the most favorable conditions for lift-off to occur. The lidar was used to scan vertical cross-plume slices 100 meter...

  10. Development, Field Testing, and Evaluation of LIDAR Assisted Controls

    Energy Technology Data Exchange (ETDEWEB)

    Ehrmann, Robert [Asltom Power Inc.; Wang, Na [National Renewable Energy Lab. (NREL), Golden, CO (United States); Scholbrock, Andrew [National Renewable Energy Lab. (NREL), Golden, CO (United States); Guadayol, Marc [Alstom Power Inc.; Wright, Alan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Arora, Dhiraj [Alstom Power Inc.

    2015-05-18

    Typical wind turbines utilize feedback controllers which have a delayed response to winds peed disturbances. A nacelle mounted LIght Detection and Ranging(LIDAR) system measures a preview wind signal in front of the turbine. This can be included in a feed-forward control system, improving turbine pitch command for incoming variations in wind speed. The overall aim is reduced blade and tower fatigue, and potentially improved annual energy production. To be successful, the LIDAR must yield accurate wind speed measurements. Therefore, a LIDAR was characterized against a nearby met tower and turbine wind speed estimator. Results indicate good correlation between measurements.

  11. Four Methods for LIDAR Retrieval of Microscale Wind Fields

    Directory of Open Access Journals (Sweden)

    Thomas Naini

    2012-08-01

    Full Text Available This paper evaluates four wind retrieval methods for micro-scale meteorology applications with volume and time resolution in the order of 30m3 and 5 s. Wind field vectors are estimated using sequential time-lapse volume images of aerosol density fluctuations. Suitably designed mono-static scanning backscatter LIDAR systems, which are sensitive to atmospheric density aerosol fluctuations, are expected to be ideal for this purpose. An important application is wind farm siting and evaluation. In this case, it is necessary to look at the complicated region between the earth’s surface and the boundary layer, where wind can be turbulent and fractal scaling from millimeter to kilometer. The methods are demonstrated using first a simple randomized moving hard target, and then with a physics based stochastic space-time dynamic turbulence model. In the latter case the actual vector wind field is known, allowing complete space-time error analysis. Two of the methods, the semblance method and the spatio-temporal method, are found to be most suitable for wind field estimation.

  12. Coastal Seabed Mapping with Hyperspectral and Lidar data

    Science.gov (United States)

    Taramelli, A.; Valentini, E.; Filipponi, F.; Cappucci, S.

    2017-12-01

    A synoptic view of the coastal seascape and its dynamics needs a quantitative ability to dissect different components over the complexity of the seafloor where a mixture of geo - biological facies determines geomorphological features and their coverage. The present study uses an analytical approach that takes advantage of a multidimensional model to integrate different data sources from airborne Hyperspectral and LiDAR remote sensing and in situ measurements to detect antropogenic features and ecological `tipping points' in coastal seafloors. The proposed approach has the ability to generate coastal seabed maps using: 1) a multidimensional dataset to account for radiometric and morphological properties of waters and the seafloor; 2) a field spectral library to assimilate the high environmental variability into the multidimensional model; 3) a final classification scheme to represent the spatial gradients in the seafloor. The spatial pattern of the response to anthropogenic forcing may be indistinguishable from patterns of natural variability. It is argued that this novel approach to define tipping points following anthropogenic impacts could be most valuable in the management of natural resources and the economic development of coastal areas worldwide. Examples are reported from different sites of the Mediterranean Sea, both from Marine Protected and un-Protected Areas.

  13. Scaling wood volume estimates from inventory plots to landscapes with airborne LiDAR in temperate deciduous forest

    Directory of Open Access Journals (Sweden)

    Shaun R. Levick

    2016-05-01

    Full Text Available Abstract Background Monitoring and managing carbon stocks in forested ecosystems requires accurate and repeatable quantification of the spatial distribution of wood volume at landscape to regional scales. Grid-based forest inventory networks have provided valuable records of forest structure and dynamics at individual plot scales, but in isolation they may not represent the carbon dynamics of heterogeneous landscapes encompassing diverse land-management strategies and site conditions. Airborne LiDAR has greatly enhanced forest structural characterisation and, in conjunction with field-based inventories, it provides avenues for monitoring carbon over broader spatial scales. Here we aim to enhance the integration of airborne LiDAR surveying with field-based inventories by exploring the effect of inventory plot size and number on the relationship between field-estimated and LiDAR-predicted wood volume in deciduous broad-leafed forest in central Germany. Results Estimation of wood volume from airborne LiDAR was most robust (R2 = 0.92, RMSE = 50.57 m3 ha−1 ~14.13 Mg C ha−1 when trained and tested with 1 ha experimental plot data (n = 50. Predictions based on a more extensive (n = 1100 plot network with considerably smaller (0.05 ha plots were inferior (R2 = 0.68, RMSE = 101.01 ~28.09 Mg C ha−1. Differences between the 1 and 0.05 ha volume models from LiDAR were negligible however at the scale of individual land-management units. Sample size permutation tests showed that increasing the number of inventory plots above 350 for the 0.05 ha plots returned no improvement in R2 and RMSE variability of the LiDAR-predicted wood volume model. Conclusions Our results from this study confirm the utility of LiDAR for estimating wood volume in deciduous broad-leafed forest, but highlight the challenges associated with field plot size and number in establishing robust relationships between airborne LiDAR and field derived wood volume. We

  14. Extraction of Features from High-resolution 3D LiDaR Point-cloud Data

    Science.gov (United States)

    Keller, P.; Kreylos, O.; Hamann, B.; Kellogg, L. H.; Cowgill, E. S.; Yikilmaz, M. B.; Hering-Bertram, M.; Hagen, H.

    2008-12-01

    Airborne and tripod-based LiDaR scans are capable of producing new insight into geologic features by providing high-quality 3D measurements of the landscape. High-resolution LiDaR is a promising method for studying slip on faults, erosion, and other landscape-altering processes. LiDaR scans can produce up to several billion individual point returns associated with the reflection of a laser from natural and engineered surfaces; these point clouds are typically used to derive a high-resolution digital elevation model (DEM). Currently, there exist only few methods that can support the analysis of the data at full resolution and in the natural 3D perspective in which it was collected by working directly with the points. We are developing new algorithms for extracting features from LiDaR scans, and present method for determining the local curvature of a LiDaR data set, working directly with the individual point returns of a scan. Computing the curvature enables us to rapidly and automatically identify key features such as ridge-lines, stream beds, and edges of terraces. We fit polynomial surface patches via a moving least squares (MLS) approach to local point neighborhoods, determining curvature values for each point. The size of the local point neighborhood is defined by a user. Since both terrestrial and airborne LiDaR scans suffer from high noise, we apply additional pre- and post-processing smoothing steps to eliminate unwanted features. LiDaR data also captures objects like buildings and trees complicating greatly the task of extracting reliable curvature values. Hence, we use a stochastic approach to determine whether a point can be reliably used to estimate curvature or not. Additionally, we have developed a graph-based approach to establish connectivities among points that correspond to regions of high curvature. The result is an explicit description of ridge-lines, for example. We have applied our method to the raw point cloud data collected as part of the Geo

  15. Scaling wood volume estimates from inventory plots to landscapes with airborne LiDAR in temperate deciduous forest.

    Science.gov (United States)

    Levick, Shaun R; Hessenmöller, Dominik; Schulze, E-Detlef

    2016-12-01

    Monitoring and managing carbon stocks in forested ecosystems requires accurate and repeatable quantification of the spatial distribution of wood volume at landscape to regional scales. Grid-based forest inventory networks have provided valuable records of forest structure and dynamics at individual plot scales, but in isolation they may not represent the carbon dynamics of heterogeneous landscapes encompassing diverse land-management strategies and site conditions. Airborne LiDAR has greatly enhanced forest structural characterisation and, in conjunction with field-based inventories, it provides avenues for monitoring carbon over broader spatial scales. Here we aim to enhance the integration of airborne LiDAR surveying with field-based inventories by exploring the effect of inventory plot size and number on the relationship between field-estimated and LiDAR-predicted wood volume in deciduous broad-leafed forest in central Germany. Estimation of wood volume from airborne LiDAR was most robust (R 2  = 0.92, RMSE = 50.57 m 3 ha -1  ~14.13 Mg C ha -1 ) when trained and tested with 1 ha experimental plot data (n = 50). Predictions based on a more extensive (n = 1100) plot network with considerably smaller (0.05 ha) plots were inferior (R 2  = 0.68, RMSE = 101.01 ~28.09 Mg C ha -1 ). Differences between the 1 and 0.05 ha volume models from LiDAR were negligible however at the scale of individual land-management units. Sample size permutation tests showed that increasing the number of inventory plots above 350 for the 0.05 ha plots returned no improvement in R 2 and RMSE variability of the LiDAR-predicted wood volume model. Our results from this study confirm the utility of LiDAR for estimating wood volume in deciduous broad-leafed forest, but highlight the challenges associated with field plot size and number in establishing robust relationships between airborne LiDAR and field derived wood volume. We are moving into a forest management era where

  16. 3D turbulence measurements using three intersecting Doppler LiDAR beams: validation against sonic anemometry

    Science.gov (United States)

    Carbajo Fuertes, Fernando; Valerio Iungo, Giacomo; Porté-Agel, Fernando

    2013-04-01

    Nowadays communities of researchers and industry in the wind engineering and meteorology sectors demand extensive and accurate measurements of atmospheric boundary layer turbulence for a better understanding of its role in a wide range of onshore and offshore applications: wind resource evaluation, wind turbine wakes, meteorology forecast, pollution and urban climate studies, etc. Atmospheric turbulence has been traditionally investigated through sonic anemometers installed on meteorological masts. However, the setup and maintenance of instrumented masts is generally very costly and the available location for the measurements is limited by the fixed position and height of the facility. In order to overcome the above-mentioned shortcomings, a measurement technique is proposed, based on the reconstruction of the three-dimensional velocity vector from simultaneous measurements of three intersecting Doppler wind LiDARs. This measuring technique presents the main advantage of being able to measure the wind velocity at any point in space inside a very large volume, which can be set and optimized for each test. Furthermore, it is very flexible regarding its transportation, installation and operation in any type of terrain. On the other hand, LiDAR measurements are strongly affected by the aerosol concentration in the air, precipitation, and the spatial and temporal resolution is poorer than that of a sonic anemometer. All this makes the comparison between these two kinds of measurements a complex task. The accuracy of the technique has been assessed by this study against sonic anemometer measurements carried out at different heights on the KNMI's meteorological mast at Cabauw's experimental site for atmospheric research (CESAR) in the Netherlands. An early uncertainty analysis shows that one of the most important parameters to be taken into account is the relative angles between the intersecting laser beams, i.e., the position of each LiDAR on the terrain and their

  17. Towards Linking 3D SAR and Lidar Models with a Spatially Explicit Individual Based Forest Model

    Science.gov (United States)

    Osmanoglu, B.; Ranson, J.; Sun, G.; Armstrong, A. H.; Fischer, R.; Huth, A.

    2017-12-01

    In this study, we present a parameterization of the FORMIND individual-based gap model (IBGM)for old growth Atlantic lowland rainforest in La Selva, Costa Rica for the purpose of informing multisensor remote sensing techniques for above ground biomass techniques. The model was successfully parameterized and calibrated for the study site; results show that the simulated forest reproduces the structural complexity of Costa Rican rainforest based on comparisons with CARBONO inventory plot data. Though the simulated stem numbers (378) slightly underestimated the plot data (418), particularly for canopy dominant intermediate shade tolerant trees and shade tolerant understory trees, overall there was a 9.7% difference. Aboveground biomass (kg/ha) showed a 0.1% difference between the simulated forest and inventory plot dataset. The Costa Rica FORMIND simulation was then used to parameterize a spatially explicit (3D) SAR and lidar backscatter models. The simulated forest stands were used to generate a Look Up Table as a tractable means to estimate aboveground forest biomass for these complex forests. Various combinations of lidar and radar variables were evaluated in the LUT inversion. To test the capability of future data for estimation of forest height and biomass, we considered data of 1) L- (or P-) band polarimetric data (backscattering coefficients of HH, HV and VV); 2) L-band dual-pol repeat-pass InSAR data (HH/HV backscattering coefficients and coherences, height of scattering phase center at HH and HV using DEM or surface height from lidar data as reference); 3) P-band polarimetric InSAR data (canopy height from inversion of PolInSAR data or use the coherences and height of scattering phase center at HH, HV and VV); 4) various height indices from waveform lidar data); and 5) surface and canopy top height from photon-counting lidar data. The methods for parameterizing the remote sensing models with the IBGM and developing Look Up Tables will be discussed. Results

  18. A Multi-temporal Analysis of Logging Impacts on Tropical Forest Structure Using Airborne Lidar Data

    Science.gov (United States)

    Keller, M. M.; Pinagé, E. R.; Duffy, P.; Longo, M.; dos-Santos, M. N.; Leitold, V.; Morton, D. C.

    2017-12-01

    The long-term impacts of selective logging on carbon cycling and ecosystem function in tropical-forests are still uncertain. Despite improvements in selective logging detection using satellite data, quantifying changes in forest structure from logging and recovery following logging is difficult using orbital data. We analyzed the dynamics of forest structure comparing logged and unlogged forests in the Eastern Brazilian Amazon (Paragominas Municipality, Pará State) using small footprint discrete return airborne lidar data acquired in 2012 and 2014. Logging operations were conducted at the 1200 ha study site from 2006 through 2013 using reduced impact logging techniques—management practices that minimize canopy and ground damage compared to more common conventional logging. Nevertheless, logging still reduced aboveground biomass by 10% to 20% in logged areas compared to intact forests. We aggregated lidar point-cloud data at spatial scales ranging from 50 m to 250 m and developed a binomial classification model based on the height distribution of lidar returns in 2012 and validated the model against the 2014 lidar acquisition. We accurately classified intact and logged forest classes compared with field data. Classification performance improved as spatial resolution increased (AUC = 0.974 at 250 m). We analyzed the differences in canopy gaps, understory damage (based on a relative density model), and biomass (estimated from total canopy height) of intact and logged classes. As expected, logging greatly increased both canopy gap formation and understory damage. However, while the area identified as canopy gap persisted for at least 8 years (from the oldest logging treatments in 2006 to the most recent lidar acquisition in 2014), the effects of ground damage were mostly erased by vigorous understory regrowth after about 5 years. The rate of new gap formation was 6 to 7 times greater in recently logged forests compared to undisturbed forests. New gaps opened at a

  19. LIDAR TS for ITER core plasma. Part II: simultaneous two wavelength LIDAR TS

    Science.gov (United States)

    Gowers, C.; Nielsen, P.; Salzmann, H.

    2017-12-01

    We have shown recently, and in more detail at this conference (Salzmann et al) that the LIDAR approach to ITER core TS measurements requires only two mirrors in the inaccessible port plug area of the machine. This leads to simplified and robust alignment, lower risk of mirror damage by plasma contamination and much simpler calibration, compared with the awkward and vulnerable optical geometry of the conventional imaging TS approach, currently under development by ITER. In the present work we have extended the simulation code used previously to include the case of launching two laser pulses, of different wavelengths, simultaneously in LIDAR geometry. The aim of this approach is to broaden the choice of lasers available for the diagnostic. In the simulation code it is assumed that two short duration (300 ps) laser pulses of different wavelengths, from an Nd:YAG laser are launched through the plasma simultaneously. The temperature and density profiles are deduced in the usual way but from the resulting combined scattered signals in the different spectral channels of the single spectrometer. The spectral response and quantum efficiencies of the detectors used in the simulation are taken from catalogue data for commercially available Hamamatsu MCP-PMTs. The response times, gateability and tolerance to stray light levels of this type of photomultiplier have already been demonstrated in the JET LIDAR system and give sufficient spatial resolution to meet the ITER specification. Here we present the new simulation results from the code. They demonstrate that when the detectors are combined with this two laser, LIDAR approach, the full range of the specified ITER core plasma Te and ne can be measured with sufficient accuracy. So, with commercially available detectors and a simple modification of a Nd:YAG laser similar to that currently being used in the design of the conventional ITER core TS design mentioned above, the ITER requirements can be met.

  20. IEA Task 32: Wind Lidar Systems for Wind Energy Deployment (LIDAR)

    Energy Technology Data Exchange (ETDEWEB)

    Kuhn, Martin; Trabucchi, Davide; Clifton, Andrew; Courtney, Mike; Rettenmeier, Andreas

    2016-05-25

    Under the International Energy Agency Wind Implementing Agreement (IEA Wind) Task 11, researchers started examining novel applications for remote sensing and the issues around them during the 51st topical expert meeting about remote sensing in January 2007. The 59th topical expert meeting organized by Task 11 in October 2009 was also dedicated to remote sensing, and the first draft of the Task's recommended practices on remote sensing was published in January 2013. The results of the Task 11 topical expert meetings provided solid groundwork for a new IEA Wind Task 32 on wind lidar technologies. Members of the wind community identified the need to consolidate the knowledge about wind lidar systems to facilitate their use, and to investigate how to exploit the advantages offered by this technology. This was the motivation that led to the start of IEA Wind Task 32 'Lidar Application for Wind Energy Deployment' in November 2011. The kick-off was meeting was held in May 2012.

  1. Terrestrial Lidar Datasets of New Orleans, Louisiana, Levee Failures from Hurricane Katrina, August 29, 2005

    Science.gov (United States)

    Collins, Brian D.; Kayen, Robert; Minasian, Diane L.; Reiss, Thomas

    2009-01-01

    Hurricane Katrina made landfall with the northern Gulf Coast on August 29, 2005, as one of the strongest hurricanes on record. The storm damage incurred in Louisiana included a number of levee failures that led to the inundation of approximately 85 percent of the metropolitan New Orleans area. Whereas extreme levels of storm damage were expected from such an event, the catastrophic failure of the New Orleans levees prompted a quick mobilization of engineering experts to assess why and how particular levees failed. As part of this mobilization, civil engineering members of the United States Geological Survey (USGS) performed terrestrial lidar topographic surveys at major levee failures in the New Orleans area. The focus of the terrestrial lidar effort was to obtain precise measurements of the ground surface to map soil displacements at each levee site, the nonuniformity of levee height freeboard, depth of erosion where scour occurred, and distress in structures at incipient failure. In total, we investigated eight sites in the New Orleans region, including both earth and concrete floodwall levee breaks. The datasets extend from the 17th Street Canal in the Orleans East Bank area to the intersection of the Gulf Intracoastal Waterway (GIWW) with the Mississippi River Gulf Outlet (MRGO) in the New Orleans East area. The lidar scan data consists of electronic files containing millions of surveyed points. These points characterize the topography of each levee's postfailure or incipient condition and are available for download through online hyperlinks. The data serve as a permanent archive of the catastrophic damage of Hurricane Katrina on the levee systems of New Orleans. Complete details of the data collection, processing, and georeferencing methodologies are provided in this report to assist in the visualization and analysis of the data by future users.

  2. High Spectral Resolution LIDAR as a Tool for Air Quality Research

    Science.gov (United States)

    Eloranta, E. W.; Spuler, S.; Hayman, M. M.

    2017-12-01

    Many aspects of air quality research require information on the vertical distribution of pollution. Traditional measurements, obtained from surface based samplers, or passive satellite remote sensing, do not provide vertical profiles. Lidar can provide profiles of aerosol properties. However traditional backscatter lidar suffers from uncertain calibrations with poorly constrained algorithms. These problems are avoided using High Spectral Resolution Lidar (HSRL) which provides absolutely calibrated vertical profiles of aerosol properties. The University of Wisconsin HSRL systems measure 532 nm wavelength aerosol backscatter cross-sections, extinction cross-sections, depolarization, and attenuated 1064 nm backscatter. These instruments are designed for long-term deployment at remote sites with minimal local support. Processed data is provided for public viewing and download in real-time on our web site "http://hsrl.ssec.wisc.edu". Air pollution applications of HSRL data will be illustrated with examples acquired during air quality field programs including; KORUS-AQ, DISCOVER-AQ, LAMOS and FRAPPE. Observations include 1) long range transport of dust, air pollution and smoke. 2) Fumigation episodes where elevated pollution is mixed down to the surface. 3) visibility restrictions by aerosols and 4) diurnal variations in atmospheric optical depth. While HSRL is powerful air quality research tool, its application in routine measurement networks is hindered by the high cost of current systems. Recent technical advances promise a next generation HSRL using telcom components to greatly reduce system cost. This paper will present data generated by a prototype low cost system constructed at NCAR. In addition to lower cost, operation at a non-visible near 780 nm infrared wavelength removes all FAA restrictions on the operation.

  3. Lidar data for the community of Golovin, Alaska

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This publication presents lidar data collected over the community of Golovin, on the southern coast of the Seward Peninsula in western Alaska (fig. 1). The original...

  4. Estimation of urban mixed layer height in Zanjan using LIDAR ...

    Indian Academy of Sciences (India)

    LIDAR observations and numerical modeling. A A Bidokhti1,∗, M ... because of the effects of aerosols, water vapor and ... J. Earth Syst. Sci. 117 ... also more abundant in the ABL apart from clouds .... Zanjan has a rather Mediterranean climate,.

  5. Augmented Reality Based Doppler Lidar Data Visualization: Promises and Challenges

    Science.gov (United States)

    Cherukuru, N. W.; Calhoun, R.

    2016-06-01

    Augmented reality (AR) is a technology in which the enables the user to view virtual content as if it existed in real world. We are exploring the possibility of using this technology to view radial velocities or processed wind vectors from a Doppler wind lidar, thus giving the user an ability to see the wind in a literal sense. This approach could find possible applications in aviation safety, atmospheric data visualization as well as in weather education and public outreach. As a proof of concept, we used the lidar data from a recent field campaign and developed a smartphone application to view the lidar scan in augmented reality. In this paper, we give a brief methodology of this feasibility study, present the challenges and promises of using AR technology in conjunction with Doppler wind lidars.

  6. Elevation - LiDAR Survey Minnehaha Creek, MN Watershed

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — LiDAR Bare-Earth Grid - Minnehaha Creek Watershed District. The Minnehaha Creek watershed is located primarily in Hennepin County, Minnesota. The watershed covers...

  7. 2006 Texas Water Development Board (TWDB) Lidar: Brazoria County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Using a LH Systems ALS50 Light Detection And Ranging (LiDAR) system, flight lines of standard density (1.4 meter ground sample distance) data were collected over...

  8. 2009 PSLC-USGS Topographic LiDAR: Wenatchee

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. (WS) collected Light Detection and Ranging (LiDAR) data of the Wenatchee USGS area of interest (AOI) east of Wenatchee, WA on May 1nd - May...

  9. Wisconsin 2008 Lidar Coverage, USACE National Coastal Mapping Program

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — The Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) has performed a coastal survey along the Lake Michigan coast of WI in 2008. The data...

  10. North Carolina 2004 Lidar Coverage, USACE National Coastal Mapping Program

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — The Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) has performed a coastal survey along the Atlantic coast of NC in 2004. The data types...

  11. Mississippi 2004 Lidar Coverage, USACE National Coastal Mapping Program

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — The Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) has performed a coastal survey along the Gulf of Mexico coastline of MS in 2004. The data...

  12. Delaware 2005 Lidar Coverage, USACE National Coastal Mapping Program

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — The Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) has performed a coastal survey along the Atlantic coast in the summer of 2005. The data...

  13. Indiana 2006 Lidar Coverage, USACE National Coastal Mapping Program

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — The Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) has performed a coastal survey along the Lake Michigan coastline in the summer of 2006....

  14. Michigan 2006 Lidar Coverage, USACE National Coastal Mapping Program

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — The Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) has performed a coastal survey along the MI coasts of Lake Huron, Lake Erie and the St....

  15. Florida 2006 Lidar Coverage, USACE National Coastal Mapping Program

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — The Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) has performed a coastal survey along the Atlantic, Gulf of Mexico in the summer of 2006....

  16. Florida 2003 Lidar Coverage, USACE National Coastal Mapping Program

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — The Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) has performed a coastal survey along the Gulf of Mexico in the summer of 2003. The data...

  17. North Carolina 2005 Lidar Coverage, USACE National Coastal Mapping Program

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — The Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) has performed a coastal survey along the Atlantic coast of NC in 2005. The data types...

  18. Alabama 2004 Lidar Coverage, USACE National Coastal Mapping Program

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — The Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) has performed a coastal survey along the Gulf of Mexico in the summer of 2004. The data...

  19. New York 2007 Lidar Coverage, USACE National Coastal Mapping Program

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — The Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) has performed a coastal survey along the Niagara River and Lake Erie and Lake Ontario...

  20. Pennsylvania 2006 Lidar Coverage, USACE National Coastal Mapping Program

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — The Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) has performed a coastal survey along the Lake Erie coast of PA in 2006. The data types...