Relevant bibliographies by topics / Physics-based Lidar

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers

Academic literature on the topic 'Physics-based Lidar'

Author: Grafiati
Published: 4 June 2021
Last updated: 4 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Physics-based Lidar.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Physics-based Lidar"

1

Newman, Jennifer F., and Andrew Clifton. "An error reduction algorithm to improve lidar turbulence estimates for wind energy." Wind Energy Science 2, no. 1 (February 10, 2017): 77–95. http://dx.doi.org/10.5194/wes-2-77-2017.

Full text
Abstract:
Abstract. 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-learning methods in L-TERRA was highly dependent on the input variables and training dataset used, suggesting that machine learning may not be the best technique for reducing lidar turbulence intensity (TI) error. Future work will include the use of a lidar simulator to better understand how different factors affect lidar turbulence error and to determine how these errors can be reduced using information from a stand-alone lidar.
APA, Harvard, Vancouver, ISO, and other styles
2

Goodin, Christopher, Justin Carrillo, J. Gabriel Monroe, Daniel W. Carruth, and Christopher R. Hudson. "An Analytic Model for Negative Obstacle Detection with Lidar and Numerical Validation Using Physics-Based Simulation." Sensors 21, no. 9 (May 5, 2021): 3211. http://dx.doi.org/10.3390/s21093211.

Full text
Abstract:
Negative obstacles have long been a challenging aspect of autonomous navigation for ground vehicles. However, as terrestrial lidar sensors have become lighter and less costly, they have increasingly been deployed on small, low-flying UAV, affording an opportunity to use these sensors to aid in autonomous navigation. In this work, we develop an analytical model for predicting the ability of UAV or UGV mounted lidar sensors to detect negative obstacles. This analytical model improves upon past work in this area because it takes the sensor rotation rate and vehicle speed into account, as well as being valid for both large and small view angles. This analytical model is used to predict the influence of velocity on detection range for a negative obstacle and determine a limiting speed when accounting for vehicle stopping distance. Finally, the analytical model is validated with a physics-based simulator in realistic terrain. The results indicate that the analytical model is valid for altitudes above 10 m and show that there are drastic improvements in negative obstacle detection when using a UAV-mounted lidar. It is shown that negative obstacle detection ranges for various UAV-mounted lidar are 60–110 m, depending on the speed of the UAV and the type of lidar used. In contrast, detection ranges for UGV mounted lidar are found to be less than 10 m.
APA, Harvard, Vancouver, ISO, and other styles
3

Sannino, Alessia, Antonella Boselli, Domenico Maisto, Alberto Porzio, Changbo Song, Nicola Spinelli, and Xuan Wang. "Development of a High Spectral Resolution Lidar for day-time measurements of aerosol extinction." EPJ Web of Conferences 197 (2019): 02009. http://dx.doi.org/10.1051/epjconf/201919702009.

Full text
Abstract:
Lidar technique is the most performing way to obtain the atmospheric vertical profile of aerosol optical properties with high space-time resolution. With elastic scattering lidars, the retrieval of aerosol optical properties (as the extinction profile) is realizable only with assumptions on aerosol extinction-to-backscatter ratio or with Raman measurement achievable in night-time. In order to overcome these problems, the High Spectral Resolution Lidar (HSRL) technique has been examined. In this paper we present an innovative prototype of High Spectral Resolution Lidar realized at Physics Department of University “Federico II” of Naples for the LISA (LIdar for Space study of the Atmosphere) project in the framework of the China-Italy international cooperation between CNISM and BRIT. The prototype which represents a first step of a spaceborne HSRL, is based on a laser source at 1064nm and 532nm with high spectral resolution ability at 532nm. The separation between the molecular and the aerosol components was obtained through the use of a confocal Fabry-Perot interferometer (CFPI) cavity.
APA, Harvard, Vancouver, ISO, and other styles
4

Zhang, Jincheng, and Xiaowei Zhao. "Spatiotemporal wind field prediction based on physics-informed deep learning and LIDAR measurements." Applied Energy 288 (April 2021): 116641. http://dx.doi.org/10.1016/j.apenergy.2021.116641.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Knobelspiesse, Kirk, Henrique M. J. Barbosa, Christine Bradley, Carol Bruegge, Brian Cairns, Gao Chen, Jacek Chowdhary, et al. "The Aerosol Characterization from Polarimeter and Lidar (ACEPOL) airborne field campaign." Earth System Science Data 12, no. 3 (September 14, 2020): 2183–208. http://dx.doi.org/10.5194/essd-12-2183-2020.

Full text
Abstract:
Abstract. In the fall of 2017, an airborne field campaign was conducted from the NASA Armstrong Flight Research Center in Palmdale, California, to advance the remote sensing of aerosols and clouds with multi-angle polarimeters (MAP) and lidars. The Aerosol Characterization from Polarimeter and Lidar (ACEPOL) campaign was jointly sponsored by NASA and the Netherlands Institute for Space Research (SRON). Six instruments were deployed on the ER-2 high-altitude aircraft. Four were MAPs: the Airborne Hyper Angular Rainbow Polarimeter (AirHARP), the Airborne Multiangle SpectroPolarimetric Imager (AirMSPI), the Airborne Spectrometer for Planetary EXploration (SPEX airborne), and the Research Scanning Polarimeter (RSP). The remainder were lidars, including the Cloud Physics Lidar (CPL) and the High Spectral Resolution Lidar 2 (HSRL-2). The southern California base of ACEPOL enabled observation of a wide variety of scene types, including urban, desert, forest, coastal ocean, and agricultural areas, with clear, cloudy, polluted, and pristine atmospheric conditions. Flights were performed in coordination with satellite overpasses and ground-based observations, including the Ground-based Multiangle SpectroPolarimetric Imager (GroundMSPI), sun photometers, and a surface reflectance spectrometer. ACEPOL is a resource for remote sensing communities as they prepare for the next generation of spaceborne MAP and lidar missions. Data are appropriate for algorithm development and testing, instrument intercomparison, and investigations of active and passive instrument data fusion. They are freely available to the public. The DOI for the primary database is https://doi.org/10.5067/SUBORBITAL/ACEPOL2017/DATA001 (ACEPOL Science Team, 2017), while for AirMSPI it is https://doi.org/10.5067/AIRCRAFT/AIRMSPI/ACEPOL/RADIANCE/ELLIPSOID_V006 and https://doi.org/10.5067/AIRCRAFT/AIRMSPI/ACEPOL/RADIANCE/TERRAIN_V006 (ACEPOL AirMSPI 75 Science Team, 2017a, b). GroundMSPI data are at https://doi.org/10.5067/GROUND/GROUNDMSPI/ACEPOL/RADIANCE_v009 (GroundMSPI Science Team, 2017). Table 3 lists further details of these archives. This paper describes ACEPOL for potential data users and also provides an outline of requirements for future field missions with similar objectives.
APA, Harvard, Vancouver, ISO, and other styles
6

Goodin, Christopher, Matthew Doude, Christopher Hudson, and Daniel Carruth. "Enabling Off-Road Autonomous Navigation-Simulation of LIDAR in Dense Vegetation." Electronics 7, no. 9 (August 21, 2018): 154. http://dx.doi.org/10.3390/electronics7090154.

Full text
Abstract:
Machine learning techniques have accelerated the development of autonomous navigation algorithms in recent years, especially algorithms for on-road autonomous navigation. However, off-road navigation in unstructured environments continues to challenge autonomous ground vehicles. Many off-road navigation systems rely on LIDAR to sense and classify the environment, but LIDAR sensors often fail to distinguish navigable vegetation from non-navigable solid obstacles. While other areas of autonomy have benefited from the use of simulation, there has not been a real-time LIDAR simulator that accounted for LIDAR–vegetation interaction. In this work, we outline the development of a real-time, physics-based LIDAR simulator for densely vegetated environments that can be used in the development of LIDAR processing algorithms for off-road autonomous navigation. We present a multi-step qualitative validation of the simulator, which includes the development of an improved statistical model for the range distribution of LIDAR returns in grass. As a demonstration of the simulator’s capability, we show an example of the simulator being used to evaluate autonomous navigation through vegetation. The results demonstrate the potential for using the simulation in the development and testing of algorithms for autonomous off-road navigation.
APA, Harvard, Vancouver, ISO, and other styles
7

Baumgarten, G., F. J. Lübken, and K. H. Fricke. "First observation of one noctilucent cloud by a twin lidar in two different directions." Annales Geophysicae 20, no. 11 (November 30, 2002): 1863–68. http://dx.doi.org/10.5194/angeo-20-1863-2002.

Full text
Abstract:
Abstract. In the early morning hours of 14 July 1999, a noctilucent cloud (NLC) was observed simultaneously by the two branches of a twin lidar system located at the ALOMAR observatory in northern Norway (69° N). The telescopes of the two lidars were pointing vertical (L^) and off the zenith by 30° (L30°). The two lidars detected an enhancement in the altitude profile of backscattered light (relative to the molecular background) for more than 5 h, starting approximately at 01:00 UT. These measurements constitute the detection of one NLC by two lidars under different directions and allow for a detailed study of the morphology of the NLC layer. A cross-correlation analysis of the NLC signals demonstrates that the main structures seen by both lidars are practically identical. This implies that a temporal evolution of the microphysics within the NLC during its drift from one lidar beam to the other is negligible. From the time delay of the NLC structures, a drift velocity of 55–65 m/s is derived which agrees nicely with radar wind measurements. During the observation period, the mean NLC altitude decreases by ~0.5 km/h (=14 cm/s) at both observation volumes. Further-more, the NLC is consistently observed approximately 500 m lower in altitude at L30° compared to L^. Supplementing these data by observations from rocket-borne and ground-based instruments, we show that the general downward progression of the NLC layer through the night, as seen by both lidars, is caused by a combination of particle sedimentation by 4–5 cm/s and a downward directed vertical wind by 9–10 cm/s, whereas a tilt of the layer in drift direction can be excluded.Key words. Atmospheric composition and structure (cloud physics and chemistry; aerosols and particles) Meteorology and atmospheric dynamics (middle atmosphere dynamics)
APA, Harvard, Vancouver, ISO, and other styles
8

Pauly, Rebecca M., John E. Yorks, Dennis L. Hlavka, Matthew J. McGill, Vassilis Amiridis, Stephen P. Palm, Sharon D. Rodier, et al. "Cloud-Aerosol Transport System (CATS) 1064 nm calibration and validation." Atmospheric Measurement Techniques 12, no. 11 (November 28, 2019): 6241–58. http://dx.doi.org/10.5194/amt-12-6241-2019.

Full text
Abstract:
Abstract. The Cloud-Aerosol Transport System (CATS) lidar on board the International Space Station (ISS) operated from 10 February 2015 to 30 October 2017 providing range-resolved vertical backscatter profiles of Earth's atmosphere at 1064 and 532 nm. The CATS instrument design and ISS orbit lead to a higher 1064 nm signal-to-noise ratio than previous space-based lidars, allowing for direct atmospheric calibration of the 1064 nm signals. Nighttime CATS version 3-00 data were calibrated by scaling the measured data to a model of the expected atmospheric backscatter between 22 and 26 km a.m.s.l. (above mean sea level). The CATS atmospheric model is constructed using molecular backscatter profiles derived from Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) reanalysis data and aerosol scattering ratios measured by the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP). The nighttime normalization altitude region was chosen to simultaneously minimize aerosol loading and variability within the CATS data frame, which extends from 28 to −2 km a.m.s.l. Daytime CATS version 3-00 data were calibrated through comparisons with nighttime measurements of the layer-integrated attenuated total backscatter (iATB) from strongly scattering, rapidly attenuating opaque cirrus clouds. The CATS nighttime 1064 nm attenuated total backscatter (ATB) uncertainties for clouds and aerosols are primarily related to the uncertainties in the CATS nighttime calibration technique, which are estimated to be ∼9 %. Median CATS V3-00 1064 nm ATB relative uncertainty at night within cloud and aerosol layers is 7 %, slightly lower than these calibration uncertainty estimates. CATS median daytime 1064 nm ATB relative uncertainty is 21 % in cloud and aerosol layers, similar to the estimated 16 %–18 % uncertainty in the CATS daytime cirrus cloud calibration transfer technique. Coincident daytime comparisons between CATS and the Cloud Physics Lidar (CPL) during the CATS-CALIPSO Airborne Validation Experiment (CCAVE) project show good agreement in mean ATB profiles for clear-air regions. Eight nighttime comparisons between CATS and the PollyXT ground-based lidars also show good agreement in clear-air regions between 3 and 12 km, with CATS having a mean ATB of 19.7 % lower than PollyXT. Agreement between the two instruments (∼7 %) is even better within an aerosol layer. Six-month comparisons of nighttime ATB values between CATS and CALIOP also show that iATB comparisons of opaque cirrus clouds agree to within 19 %. Overall, CATS has demonstrated that direct calibration of the 1064 nm channel is possible from a space-based lidar using the atmospheric normalization technique.
APA, Harvard, Vancouver, ISO, and other styles
9

Mereu, Luigi, Simona Scollo, Antonella Boselli, Giuseppe Leto, Ricardo Zanmar Sanchez, Costanza Bonadonna, and Frank Silvio Marzano. "Dual-Wavelength Polarimetric Lidar Observations of the Volcanic Ash Cloud Produced during the 2016 Etna Eruption." Remote Sensing 13, no. 9 (April 29, 2021): 1728. http://dx.doi.org/10.3390/rs13091728.

Full text
Abstract:
Lidar observations are very useful to analyse dispersed volcanic clouds in the troposphere mainly because of their high range resolution, providing morphological as well as microphysical (size and mass) properties. In this work, we analyse the volcanic cloud of 18 May 2016 at Mt. Etna, in Italy, retrieved by polarimetric dual-wavelength Lidar measurements. We use the AMPLE (Aerosol Multi-Wavelength Polarization Lidar Experiment) system, located in Catania, about 25 km from the Etna summit craters, pointing at a thin volcanic cloud layer, clearly visible and dispersed from the summit craters at the altitude between 2 and 4 km and 6 and 7 km above the sea level. Both the backscattering and linear depolarization profiles at 355 nm (UV, ultraviolet) and 532 nm (VIS, visible) wavelengths, respectively, were obtained using different angles at 20°, 30°, 40° and 90°. The proposed approach inverts the Lidar measurements with a physically based inversion methodology named Volcanic Ash Lidar Retrieval (VALR), based on Maximum-Likelihood (ML). VALRML can provide estimates of volcanic ash mean size and mass concentration at a resolution of few tens of meters. We also compared those results with two methods: Single-variate Regression (SR) and Multi-variate Regression (MR). SR uses the backscattering coefficient or backscattering and depolarization coefficients of one wavelength (UV or VIS in our cases). The MR method uses the backscattering coefficient of both wavelengths (UV and VIS). In absence of in situ airborne validation data, the discrepancy among the different retrieval techniques is estimated with respect to the VALR ML algorithm. The VALR ML analysis provides ash concentrations between about 0.1 μg/m3 and 1 mg/m3 and particle mean sizes of 0.1 μm and 6 μm, respectively. Results show that, for the SR method differences are less than <10%, using the backscattering coefficient only and backscattering and depolarization coefficients. Moreover, we find differences of 20–30% respect to VALR ML, considering well-known parametric retrieval methods. VALR algorithms show how a physics-based inversion approaches can effectively exploit the spectral-polarimetric Lidar AMPLE capability.
APA, Harvard, Vancouver, ISO, and other styles
10

Midzak, Natalie, John E. Yorks, Jianglong Zhang, Bastiaan van Diedenhoven, Sarah Woods, and Matthew McGill. "A Classification of Ice Crystal Habits Using Combined Lidar and Scanning Polarimeter Observations during the SEAC4RS Campaign." Journal of Atmospheric and Oceanic Technology 37, no. 12 (December 2020): 2185–96. http://dx.doi.org/10.1175/jtech-d-20-0037.1.

Full text
Abstract:
AbstractUsing collocated NASA Cloud Physics Lidar (CPL) and Research Scanning Polarimeter (RSP) data from the Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) campaign, a new observational-based method was developed which uses a K-means clustering technique to classify ice crystal habit types into seven categories: column, plates, rosettes, spheroids, and three different type of irregulars. Intercompared with the collocated SPEC, Inc., Cloud Particle Imager (CPI) data, the frequency of the detected ice crystal habits from the proposed method presented in the study agrees within 5% with the CPI-reported values for columns, irregulars, rosettes, and spheroids, with more disagreement for plates. This study suggests that a detailed ice crystal habit retrieval could be applied to combined space-based lidar and polarimeter observations such as CALIPSO and POLDER in addition to future missions such as the Aerosols, Clouds, Convection, and Precipitation (A-CCP).
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Physics-based Lidar"

1

Foster, Michael S. "Using Lidar to geometrically-constrain signature spaces for physics-based target detection /." Online version of thesis, 2007. http://hdl.handle.net/1850/5827.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

"Physics-Based Lidar Simulation and Wind Gust Detection and Impact Prediction for Wind Turbines." Doctoral diss., 2019. http://hdl.handle.net/2286/R.I.53921.

Full text
Abstract:
abstract: Lidar has demonstrated its utility in meteorological studies, wind resource assessment, and wind farm control. More recently, lidar has gained widespread attention for autonomous vehicles. The first part of the dissertation begins with an application of a coherent Doppler lidar to wind gust characterization for wind farm control. This application focuses on wind gusts on a scale from 100 m to 1000 m. A detecting and tracking algorithm is proposed to extract gusts from a wind field and track their movement. The algorithm was implemented for a three-hour, two-dimensional wind field retrieved from the measurements of a coherent Doppler lidar. The Gaussian distribution of the gust spanwise deviation from the streamline was demonstrated. Size dependency of gust deviations is discussed. A prediction model estimating the impact of gusts with respect to arrival time and the probability of arrival locations is introduced. The prediction model was applied to a virtual wind turbine array, and estimates are given for which wind turbines would be impacted. The second part of this dissertation describes a Time-of-Flight lidar simulation. The lidar simulation includes a laser source module, a propagation module, a receiver module, and a timing module. A two-dimensional pulse model is introduced in the laser source module. The sampling rate for the pulse model is explored. The propagation module takes accounts of beam divergence, target characteristics, atmosphere, and optics. The receiver module contains models of noise and analog filters in a lidar receiver. The effect of analog filters on the signal behavior was investigated. The timing module includes a Time-to-Digital Converter (TDC) module and an Analog-to-Digital converter (ADC) module. In the TDC module, several walk-error compensation methods for leading-edge detection and multiple timing algorithms were modeled and tested on simulated signals. In the ADC module, a benchmark (BM) timing algorithm is proposed. A Neyman-Pearson (NP) detector was implemented in the time domain and frequency domain (fast Fourier transform (FFT) approach). The FFT approach with frequency-domain zero-paddings improves the timing resolution. The BM algorithm was tested on simulated signals, and the NP detector was evaluated on both simulated signals and measurements from a prototype lidar (Bhaskaran, 2018).
Dissertation/Thesis
Doctoral Dissertation Mechanical Engineering 2019
APA, Harvard, Vancouver, ISO, and other styles
3

Mbatha, Nkanyiso Bongumusa. "Study on 2002 sudden stratospheric warming, mesopher-lower thermospheric wind structure and dynamics and middle atmospheric structure, based on superDARN HF RADAR, LIDAR, Riometer, satellites and models." Thesis, 2012. http://hdl.handle.net/10413/9731.

Full text
Abstract:
In this thesis, the dynamics and coupling in the middle atmosphere over the Southern Hemisphere are investigated using SuperDARN high frequency (HF) radar wind data, satellites, light detection and ranging (LIDAR), the South African National Antarctic Expedition (SANAE) imaging riometer and models. In particular, the study focuses on the unprecedented 2002 major stratospheric warming and its role in coupling the middle atmosphere. The dynamics of the middle atmosphere is investigated in terms of mean wind, temperature, gravity waves and planetary wave activity. Studying the middle atmospheric thermal structure over Southern Africa is an important activity to improve the understanding of atmospheric dynamics of this region. Observation of a middle atmosphere thermal structure over Durban (29.9 S, 31.0 E, South Africa) using LIDAR data collected from April 1999 to July 2004 (277 nights), including closest overpasses of the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) and Halogen Occultation Experiments (HALOE) satellites, and the COSPAR International Reference Atmosphere (CIRA-86) are presented in this thesis. The observations from the LIDAR instrument, satellites and CIRA-86 exhibit the presence of annual oscillation in the stratosphere, whereas in the mesosphere the semi-annual oscillation seems to dominate the annual oscillation at some levels. The stratopause is observed in the height range of 40-55 km for all the instruments, with the stratopause temperatures being 260- 270 K for the LIDAR, 250-260 K for the SABER, and 250-270 K for the HALOE. Data from the LIDAR, satellites and CIRA-86 model indicate almost the same thermal structure of the middle atmosphere over Durban. This indicates a good agreement between LIDAR, satellites and the CIRA-86 model. Mean wind and planetary waves are investigated on a climatological scale in this study. Mean wind observations from the SANAE SuperDARN HF radar are compared with observations from Halley SuperDARN HF radar. There is a good agreement between the observations from the two stations both in the zonal and meridional wind components. Zonal wind is observed to be consistently larger than the meridional wind. The zonal wind is also consistently more eastward at both stations with maxima occurring during the solstice months. High latitude summer zonal mean ow at 94 km is observed to be weaker and more variable compared to the eastward winter mean circulation owing to tropospherically forced planetary waves propagating through the middle atmosphere. The zonal mean wind shows greater seasonal variability than does the meridional mean wind. This seasonal behaviour is reasonably well understood in terms of the upward propagating planetary waves and gravity waves interacting with the mean ow. The Coriolis force also plays an important role in the case of meridional wind component. The climatology of planetary waves both in the zonal and meridional wind components indicates an ampli cation of planetary waves of shorter wavenumbers (s = 3) in the winter months. During summer, long period oscillations (e.g. >10 days) which are dominant in winter disappear, and oscillations with shorter period (e.g. <10 days) become dominant. vi There is a strong planetary wave coupling between the stratosphere and mesosphere-lower thermospheric (MLT) during the year 2002 winter season, whilst the coupling is observed to be relatively weak during the other years. The strong planetary wave coupling in 2002 is understandable because during this year the middle atmosphere winter months were characterised by strong planetary wave activity which led to the rst ever detection of the SSW in the Southern Hemisphere. In the year 2002 winter period the mean circulation in the stratosphere is characterized by a series of planetary wave events that weakened the polar vortex and triggered the sudden stratospheric warming in late September. In particular, in the stratosphere there is a presence of a quasi 10-day eastward propagating planetary wave of wavenumber s=1, while in the MLT a quasi 14-day eastward propagating planetary wave of wavenumber s=1 is observed to be dominant. The Eliassen Palm ux (E-P) ux shows that strong planetary wave activity observed in the middle atmosphere originates from the troposphere. Zonal winds at the MLT show reversal approximately 7 days before the reversal at stratosphere, indicating a downwards propagation of circulation disturbance in the middle atmosphere. Eastward zonal winds dominate the winter MLT, but during the 2002 winter there are many periods of westward winds observed compared to the other years. The SABER vertical temperature pro les indicate cooling of the MLT region during the SSW occurrence. Gravity wave horizontal phase velocities and horizontal wavelengths as seen by the SANAE imaging riometer are observed to reduce dramatically over SANAE during the occurrence of the stratospheric warming. The disturbance of the middle atmosphere during the Southern Hemisphere stratospheric warming in year 2002 winter preconditioned the region for gravity waves to propagate upward to the MLT. The potential energy of these gravity waves is observed to increase with height up until they reach the lower thermosphere. At the MLT they lose their energy, thus depositing their momentum, leading to the MLT cooling and mean wind reversal. Keywords: SSW, Planetary waves, Gravity waves, Stratosphere, MLT, SuperDARN radar, Mean wind, Temperature, Middle atmosphere, SANAE.
Thesis (Ph.D.)-University of KwaZulu-Natal, Westville, 2012.
APA, Harvard, Vancouver, ISO, and other styles
4

"Understanding the interaction of wind farms and turbulent atmospheric boundary layer in a large eddy simulation framework: from periodic to LIDAR based data driven cases." Doctoral diss., 2018. http://hdl.handle.net/2286/R.I.49173.

Full text
Abstract:
abstract: This thesis focuses on an improved understanding of the dynamics at different length scales of wind farms in an atmospheric boundary layer (ABL) using a series of visualization studies and Fourier, wavelet based spectral analysis using high fidelity large eddy simulation (LES). For this purpose, a robust LES based neutral ABL model at very high Reynolds number has been developed using a high order spectral element method which has been validated against the previous literature. This ABL methodology has been used as a building block to drive large wind turbine arrays or wind farms residing inside the boundary layer as documented in the subsequent work. Studies conducted in the thesis involving massive periodic wind farms with neutral ABL have indicated towards the presence of large scale coherent structures that contribute to the power generated by the wind turbines via downdraft mechanisms which are also responsible for the modulation of near wall dynamics. This key idea about the modulation of large scales have seen a lot of promise in the application of flow past vertically staggered wind farms with turbines at different scales. Eventually, studies involving wind farms have been progressively evolved in a framework of inflow-outflow where the turbulent inflow is being fed from the precursor ABL using a spectral interpolation technique. This methodology has been used to enhance the understanding related to the multiscale physics of wind farm ABL interaction, where phenomenon like the growth of the inner layer, and wake impingement effects in the subsequent rows of wind turbines are important owing to the streamwise heterogeneity of the flow. Finally, the presence of realistic geophysical effects in the turbulent inflow have been investigated that influence the flow past the wind turbine arrays. Some of the geophysical effects that have been considered include the presence of the Coriolis forces as well as the temporal variation of mean wind magnitude and direction that might occur due to mesoscale dynamics. This study has been compared against field experimental results which provides an important step towards understanding the capability of the mean data driven LES methodology in predicting realistic flow structures.
Dissertation/Thesis
Turbulent flow past a large periodic wind farm
Doctoral Dissertation Mechanical Engineering 2018
APA, Harvard, Vancouver, ISO, and other styles

Books on the topic "Physics-based Lidar"

1

United States. National Aeronautics and Space Administration. and Simpson Weather Associates, eds. Influence of coherent mesoscale structures on satellite-based Doppler lidar wind measurements: Monthly progress report for May 1985. Charlottesville, VA: Simpson Weather Associates, Inc., 1985.

Find full text
APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Physics-based Lidar"

1

Sassen, Kenneth, and Gerald Mace. "Ground-based Remote Sensing of Cirrus Clouds." In Cirrus. Oxford University Press, 2002. http://dx.doi.org/10.1093/oso/9780195130720.003.0012.

Full text
Abstract:
Cirrus clouds have only recently been recognized as having a significant influence on weather and climate through their impact on the radiative energy budget of the atmosphere. In addition, the unique difficulties presented by the study of cirrus put them on the “back burner” of atmospheric research for much of the twentieth century. Foremost, because they inhabit the frigid upper troposphere, their inaccessibility has hampered intensive research. Other factors have included a lack of in situ instrumentation to effectively sample the clouds and environment, and basic uncertainties in the underlying physics of ice cloud formation, growth, and maintenance. Cloud systems that produced precipitation, severe weather, or hazards to aviation were deemed more worthy of research support until the mid- 1980s. Beginning at this time, however, major field research programs such as the First ISCCP (International Satellite Cloud Climatology Program) Regional Experiment (FIRE; Cox et al. 1987), International Cirrus Experiment (ICE; Raschke et al. 1990), Experimental Cloud Lidar Pilot Study (ECLIPS; Platt et al. 1994), and the Atmospheric Radiation Measurement (ARM) Program (Stokes and Schwartz 1994) have concentrated on cirrus cloud research, relying heavily on ground-based remote sensing observations combined with research aircraft. What has caused this change in research emphasis is an appreciation for the potentially significant role that cirrus play in maintaining the radiation balance of the earth-atmosphere system (Liou 1986). As climate change issues were treated more seriously, it was recognized that the effects, or feedbacks, of extensive high-level ice clouds in response to global warming could be pivotal. This fortunately came at a time when new generations of meteorological instrumentation were becoming available. Beginning in the early 1970s, major advancements were made in the fields of numerical cloud modeling and cloud measurements using aircraft probes, satellite multispectral imaging, and remote sensing with lidar, short-wavelength radar, and radiometers, all greatly facilitating cirrus research. Each of these experimental approaches have their advantages and drawbacks, and it should also be noted that a successful cloud modeling effort relies on field data for establishing boundary conditions and providing case studies for validation. Although the technologies created for in situ aircraft measurements can clearly provide unique knowledge of cirrus cloud thermodynamic and microphysical properties (Dowling and Radke 1990), available probes may suffer from limitations in their response to the wide range of cirrus particles and actually sample a rather small volume of cloud during any mission.
APA, Harvard, Vancouver, ISO, and other styles
2

Del, Massimo, Massimo Baldi, and Francesco Castagnoli. "A Photodiode-Based, Low-Cost Telemetric- Lidar for the Continuous Monitoring of Urban Particulate Matter." In Photodiodes - Communications, Bio-Sensings, Measurements and High-Energy Physics. InTech, 2011. http://dx.doi.org/10.5772/19328.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Physics-based Lidar"

1

Givens, Ryan N., Karl C. Walli, and Michael T. Eismann. "Evaluating the Lidar/HSI direct method for physics-based scene modeling." In 2014 IEEE Applied Imagery Pattern Recognition Workshop (AIPR). IEEE, 2014. http://dx.doi.org/10.1109/aipr.2014.7041906.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Heiden, Eric, Ziang Liu, Ragesh K. Ramachandran, and Gaurav S. Sukhatme. "Physics-based Simulation of Continuous-Wave LIDAR for Localization, Calibration and Tracking." In 2020 IEEE International Conference on Robotics and Automation (ICRA). IEEE, 2020. http://dx.doi.org/10.1109/icra40945.2020.9197138.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Foster, Michael S., John R. Schott, David W. Messinger, and Rolando Raqueño. "Use of Lidar data to geometrically constrain radiance spaces for physics-based target detection." In Photonic Devices + Applications, edited by Sylvia S. Shen and Paul E. Lewis. SPIE, 2007. http://dx.doi.org/10.1117/12.729488.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Galkin, K., P. Gubko, M. Ivanov, and G. Tulinov. "Lidar measurements of upper and middle atmospheric temperatures based on new configuration of multifunctional lidar of altitude sounding." In XXI International Symposium Atmospheric and Ocean Optics. Atmospheric Physics, edited by Oleg A. Romanovskii. SPIE, 2015. http://dx.doi.org/10.1117/12.2206121.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Mitev, Valentin, Renaud Matthey, and Vladislav Makarov. "Compact micropulse backscatter lidar: airborne and ground-based applications." In International Conference and School on Quantum Electronics "Laser Physics and Applications" - ICSQE 2016, edited by Tanja Dreischuh, Sanka Gateva, Albena Daskalova, and Alexandros Serafetinides. SPIE, 2017. http://dx.doi.org/10.1117/12.2261976.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Tan, Fuyi, Boon Chun Beh, Chun Ho Tan, Hwee San Lim, Khiruddin Abdullah, Mohamad Zubir Mat Jafri, Ellsworth Judd Welton, and Simone Lolli. "Preliminary analysis of ground based lidar backscattered signal and performance evaluation in Penang Island." In 2012 NATIONAL PHYSICS CONFERENCE: (PERFIK 2012). AIP, 2013. http://dx.doi.org/10.1063/1.4803584.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Hee, Wan Shen, Wei Ying Khor, Hwee San Lim, and Mohamad Zubir Mat Jafri. "Intercomparison of two haze events observed using a ground-based backscatter lidar in Penang Island, Malaysia." In NATIONAL PHYSICS CONFERENCE 2014 (PERFIK 2014). AIP Publishing LLC, 2015. http://dx.doi.org/10.1063/1.4915176.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Bochkovskii, Dmitry A., and Valerii N. Marichev. "Investigation of the variability of stratospheric filling by background aerosol over Tomsk in 2017 based on lidar sounding." In XXIV International Symposium, Atmospheric and Ocean Optics, Atmospheric Physics, edited by Oleg A. Romanovskii and Gennadii G. Matvienko. SPIE, 2018. http://dx.doi.org/10.1117/12.2504366.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Samokhvalov, I. V., V. V. Belov, B. V. Kaul, V. V. Bryukhanova, S. V. Nasonov, I. D. Bryukhanov, and M. V. Tarasenkov. "Analysis of experiments on high-level cloud sensing with a satellite radiometer and a ground-based polarization lidar." In 20th International Symposium on Atmospheric and Ocean Optics: Atmospheric Physics, edited by Oleg A. Romanovskii. SPIE, 2014. http://dx.doi.org/10.1117/12.2075847.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Bochkovskii, Dmitry A., and Valerii N. Marichev. "Investigations of thermal regime of the stratosphere over Tomsk in 2011 - 2015 based on the data of lidar sounding." In XXIV International Symposium, Atmospheric and Ocean Optics, Atmospheric Physics, edited by Oleg A. Romanovskii and Gennadii G. Matvienko. SPIE, 2018. http://dx.doi.org/10.1117/12.2504375.

Full text
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Physics-based Lidar' for particular source types:
Journal articles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography