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  • Atmospheric boundary layer height monitoring using a kalman filter and backscatter lidar returns

     Lange, Diego; Tiana Alsina, Jordi; Saeed, Umar; Tomás Martinez, Sergio; Rocadenbosch Burillo, Francisco
    IEEE transactions on geoscience and remote sensing
    Vol. 52, num. 8, p. 4717-4728
    DOI: 10.1109/TGRS.2013.2284110
    Date of publication: 2014-08-01
    Journal article

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    A solution based on a Kalman filter to trace the evolution of the atmospheric boundary layer (ABL) sensed by a ground-based elastic-backscatter tropospheric lidar is presented. An erf-like profile is used to model the mixing-layer top and the entrainment-zone thickness. The extended Kalman filter (EKF) enables to retrieve and track the ABL parameters based on simplified statistics of the ABL dynamics and of the observation noise present in the lidar signal. This adaptive feature permits to analyze atmospheric scenes with low signal-to-noise ratios (SNRs) without the need to resort to long-time averages or range-smoothing techniques, as well as to pave the way for future automated detection solutions. First, EKF results based on oversimplified synthetic and experimental lidar profiles are presented and compared with classic ABL estimation quantifiers for a case study with different SNR scenarios.

    A solution based on a Kalman filter to trace the evolution of the atmospheric boundary layer (ABL) sensed by a ground-based elastic-backscatter tropospheric lidar is presented. An erf-like profile is used to model the mixing-layer top and the entrainment-zone thickness. The extended Kalman filter (EKF) enables to retrieve and track the ABL parameters based on simplified statistics of the ABL dynamics and of the observation noise present in the lidar signal. This adaptive feature permits to analyze atmospheric scenes with low signal-to-noise ratios (SNRs) without the need to resort to long-time averages or range-smoothing techniques, as well as to pave the way for future automated detection solutions. First, EKF results based on oversimplified synthetic and experimental lidar profiles are presented and compared with classic ABL estimation quantifiers for a case study with different SNR scenarios.

  • LIDAR as an alternative to passive collectors to measure pesticide spray drift

     Gregorio, Eduard; Rosell-Polo, Joan R.; Sanz Cortiella, Ricardo; Rocadenbosch Burillo, Francisco; Solanelles, Francesc; Garcerá, Cruz; Chueca, Patricia; Arnó, Jaume; Del Moral, Ignacio; Masip, Joan; Camp, Ferran; Viana, Rafarl; Escolà, Alexandre; Gràcia, Felip; Planas, Santiago; Moltó, Enrique
    Atmospheric environment
    Vol. 82, p. 83-93
    DOI: 10.1016/j.atmosenv.2013.09.028
    Date of publication: 2014-01
    Journal article

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    Pesticide spray drift entails a series of risks and costs in terms of human, animal and environmental well-being. A proper understanding of this phenomenon is essential to minimise these risks. However, most conventional methods used in drift measurement are based on point collectors which are unable to obtain information concerning the temporal or spatial evolution of the pesticide cloud. Such methods are also costly, labour-intensive, and require a considerable amount of time. The aim of this paper is to propose a method to measure the spray drift based on lidar (LIght Detection And Ranging) and to prove that it can be an alternative to passive collectors. An analytical model is proposed to relate the measurements obtained through passive collectors and those obtained with lidar systems considering several spray application and meteorological parameters. The model was tested through an experimental campaign involving multiple ground spray tests. A lidar system and two types of passive collectors (nylon strings and water-sensitive paper) were used simultaneously to measure the drift. The results showed for each test a high coefficient of determination (R2¿0.90) between the lidar signal and the tracer mass captured by the nylon strings. This coefficient decreased (R2=0.77) when all tests were considered together. Lidar measurements were also used to study the evolution of the pesticide cloud with high range (1.5m) and temporal resolution (1s) and to estimate its velocity. Furthermore, a very satisfactory adjustment (R2=0.89) was observed between the tracer mass collected by the nylon lines and the coverage on water-sensitive paper sheets. These results are in accordance with the proposed analytical model and allow the conclusion that the application and meteorological parameters can be considered spatially invariant for a given test but are not invariant for different tests.

  • Lidar and S-band radar profiling of the atmosphere: Adaptive processing for Boundary-Layer monitoring, optical-parameter error estimation, and application cases  Open access

     Lange Vega, Diego
    Universitat Politècnica de Catalunya
    Theses

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    La tesis doctoral aborda la teledetecció atmosfèrica amb tècniques lidar i radar (banda S) i llur tractament del senyal. La teledetecció activa amb aquests instruments ofereix resolucions espacials i temporals sense precedents en la perfilometria vertical de l¿atmosfera i recuperació de productes de dades òptics i físics atmosfèrics en un marc de creixent regulació mediambiental. El primer objectiu d¿aquesta tesi concerneix l¿estimació de cotes d¿error en la inversió del perfil del coeficient de retrodispersió atmosfèrica a partir de senyals lidar de tipus elàstic (és a dir, sense desplaçament de la longitud d¿ona en recepció al interactuar amb els dispersors atmosfèrics) mitjançant l¿algorisme d¿inversió de dues components de Klett-Fernald-Sasano. Aquest objectiu parteix de treballs previs en el Remote Sensing Lab. (RSLab) de la Universitat Politècnica de Catalunya (UPC) i permet obtenir cotes de primer ordre (aproximades) basades en propagació d¿errors i cotes (exactes) basades en el increment total de l¿error. Característica diferencial en front l¿estat de l¿art és l¿assimilació d¿errors sistemàtics (per exemple, entrades de cal¿libració d¿usuari) i aleatoris (relació senyal-soroll, SNR, finita) en forma matemàtica explícita.El segon objectiu, central de la tesis, aborda l¿estimació de l¿altura de la capa límit atmosfèrica (ABLH) a partir de senyal lidar elàstics i d¿observacions radar en banda S (ona continua amb modulació en freqüència, FMCW) utilitzant tècniques adaptatives basades en filtrat estès de Kalman (EKF). El filtre es basa en modelat morfològic de la transició atmosfèrica entre la capa de mescla i la troposfera lliure i en l¿estimació continua de la informació de covariança del soroll. En el prototipus lidar-EKF la tècnica proposada millora clarament les tècniques clàssiques d¿estimació de la ABLH como són les basades en mètodes derivatius, decisió de llindar, o el mètode de la variança-centroide. La formulació EKF s¿aplica tant a mesures procedents de ceilòmetres lidar como de la pròpia estació lidar UPC en escenes d¿alta i baixa SNR. Addicionalment, l¿enfoc lidar-EKF es reformula i s¿estén amb èxit a escenes radar en banda S (dispersió Bragg) en presència de fonts de soroll interferent (dispersió Rayleigh de, per exemple, insectes i ocells). En aquest context, la característica FMCW permet la capacitat de resolució en distància. L¿estimació de la ABLH amb els prototipus lidar-EKF i radar-EKF s¿intercompara en campanyes de mesura.Finalment, el tercer objectiu atén a l¿explotació de l¿estació lidar UPC existent: En una primera part introductòria, es formula un algorisme modificat de ¿gluing¿ per a la millora del marge dinàmic de canals lidar elàstics mitjançant combinació (o ¿enganxat¿) de senyals lidar adquirits analògicament i amb foto-comptatge. En una segona part, es presenten dos exemples (incloent l¿aplicació de l¿algorisme de ¿gluing¿) que il¿lustren les capacitats del lidar de la UPC en l¿observació atmosfèrica de dos recents erupcions volcàniques des de la xarxa d¿observació EARLINET (European Aerosol Research Lidar Network). Aquesta última és part de GALION (Global Atmospheric Watch Atmospheric Lidar Observation Network)-GEOSS (Global Earth Observation System of Systems).

    This Ph.D. thesis addresses remote sensing of the atmosphere by means of lidar and S-band clear-air weather radar, and related data signal processing. Active remote sensing by means of these instruments offers unprecedented capabilities of spatial and temporal resolutions for vertical atmospheric profiling and the retrieval of key optical and physical atmospheric products in an increasing environmental regulatory framework. The first goal is this Ph.D. concerns the estimation of error bounds in the inversion of the profile of the atmospheric backscatter coefficient from elastic lidar signals (i.e., without wavelength shift in reception when interacting with atmospheric scatterers) by means of the two-component inversion algorithm (the so-called Klett-Fernald-Sasano¿s algorithm). This objective departs from previous works at the Remote Sensing Lab. (RSLab) of the Universitat Politècnica de Catalunya (UPC) and derives first-order error-propagated bounds (approximate) and total-increment bounds (exact). As distinctive feature in the state of the art, the error bounds merge into a single body both systematic (i.e., user-calibration inputs) and random error sources (finite signal-to-noise ratio, SNR) yielding an explicit mathematical form. The second goal, central to this Ph.D., tackles retrieval of the Atmospheric Boundary Layer Height (ABLH) from elastic lidar and S-band Frequency-Modulated Continuous-Wave (FMCW) radar observations by using adaptive techniques based on the Extended Kalman Filter (EKF). The filter is based on morphological modelling of the Mixing-Layer-to-Free-Troposphere transition and continuous estimation of the noise covariance information. In the lidar-EKF realization the proposed technique is shown to outperform classic ABLH estimators such as those based on derivative techniques, thresholded decision, or the variance centroid method. The EKF formulation is applied to both ceilometer and UPC lidar records in high- and low-SNR scenes. The lidar-EKF approach is re-formulated and successfully extended to S-band radar scenes (Bragg¿s scattering) in presence of interferent noise sources (Rayleigh scattering from e.g., insects and birds). In this context, the FMCW feature enables the range-resolved capability. EKF-lidar and EKF-radar ABLH estimates are cross-examined from field campaign results. Finally, the third goal deals with exploitation of the existing UPC lidar station: In a first introductory part, a modified algorithm for enhancing the dynamic range of elastic lidar channels by ¿gluing¿ analog and photon-counting data records is formulated. In a second part, two case examples (including application of the gluing algorithm) are presented to illustrate the capabilities of the UPC lidar in networked atmospheric observation of two recent volcano eruption events as part of the EARLINET (European Aerosol Research Lidar Network). The latter is part of GALION (Global Atmospheric Watch Atmospheric Lidar Observation Network)-GEOSS (Global Earth Observation System of Systems) framework.

    La tesis doctoral aborda la teledetecció atmosfèrica amb tècniques lidar i radar (banda S) i llur tractament del senyal. La teledetecció activa amb aquests instruments ofereix resolucions espacials i temporals sense precedents en la perfilometria vertical de l'atmosfera i recuperació de productes de dades òptics i físics atmosfèrics en un marc de creixent regulació mediambiental. El primer objectiu d'aquesta tesi concerneix l'estimació de cotes d'error en la inversió del perfil del coeficient de retrodispersió atmosfèrica a partir de senyals lidar de tipus elàstic (és a dir, sense desplaçament de la longitud d'ona en recepció al interactuar amb els dispersors atmosfèrics) mitjançant l'algorisme d'inversió de dues components de Klett-Fernald-Sasano. Aquest objectiu parteix de treballs previs en el Remote Sensing Lab. (RSLab) de la Universitat Politècnica de Catalunya (UPC) i permet obtenir cotes de primer ordre (aproximades) basades en propagació d'errors i cotes (exactes) basades en el increment total de l'error. Característica diferencial en front l'estat de l'art és l'assimilació d'errors sistemàtics (per exemple, entrades de cal.libració d'usuari) i aleatoris (relació senyal-soroll, SNR, finita) en forma matemàtica explícita. El segon objectiu, central de la tesis, aborda l'estimació de l'altura de la capa límit atmosfèrica (ABLH) a partir de senyal lidar elàstics i d'observacions radar en banda S (ona continua amb modulació en freqüència, FMCW) utilitzant tècniques adaptatives basades en filtrat estès de Kalman (EKF). El filtre es basa en modelat morfològic de la transició atmosfèrica entre la capa de mescla i la troposfera lliure i en l'estimació continua de la informació de covariança del soroll. En el prototipus lidar-EKF la tècnica proposada millora clarament les tècniques clàssiques d'estimació de la ABLH como són les basades en mètodes derivatius, decisió de llindar, o el mètode de la variança-centroide. La formulació EKF s'aplica tant a mesures procedents de ceilòmetres lidar como de la pròpia estació lidar UPC en escenes d'alta i baixa SNR. Addicionalment, l'enfoc lidar-EKF es reformula i s'estén amb èxit a escenes radar en banda S (dispersió Bragg) en presència de fonts de soroll interferent (dispersió Rayleigh de, per exemple, insectes i ocells). En aquest context, la característica FMCW permet la capacitat de resolució en distància. L'estimació de la ABLH amb els prototipus lidar-EKF i radar-EKF s'intercompara en campanyes de mesura. Finalment, el tercer objectiu atén a l'explotació de l'estació lidar UPC existent: En una primera part introductòria, es formula un algorisme modificat de "gluing" per a la millora del marge dinàmic de canals lidar elàstics mitjançant combinació (o "enganxat") de senyals lidar adquirits analògicament i amb foto-comptatge. En una segona part, es presenten dos exemples (incloent l'aplicació de l'algorisme de "gluing") que il.lustren les capacitats del lidar de la UPC en l'observació atmosfèrica de dos recents erupcions volcàniques des de la xarxa d'observació EARLINET (European Aerosol Research Lidar Network). Aquesta última és part de GALION (Global Atmospheric Watch Atmospheric Lidar Observation Network)-GEOSS (Global Earth Observation System of Systems).

  • Wavelet correlation transform method and gradient method to determine aerosol layering from lidar returns: Some comments

     Comeron Tejero, Adolfo; Sicard, Michaël; Rocadenbosch Burillo, Francisco
    Journal of atmospheric and oceanic technology
    Vol. 30, num. 6, p. 1189-1193
    DOI: 10.1175/JTECH-D-12-00233.1
    Date of publication: 2013-06
    Journal article

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    Identification of aerosol layers on lidar measurements is of interest to determine ranges where aerosol properties are likely to be homogeneous and to infer transport phenomena and atmosphere dynamics. For instance, the range-corrected backscattered signal from aerosol measured with lidars has long been used as a proxy to determine the depth of the planetary boundary layer. The method relies on the assumption that in a well-mixed atmosphere, a rather homogenous aerosol distribution will exist within the boundary layer; hence, a sudden drop in the lidar range-corrected signal profile will mark the end of the layer. The most usual methods to detect that drop are the gradient method, which detects a negative maximum in the derivative with respect to range of the lidar range-corrected signal, or of its logarithm, and the wavelet correlation transform method, which detects a maximum in the correlation function of the lidar range-corrected signal and a wavelet, usually the Haar wavelet. These methods are not restricted to determining the boundary layer height but can also be used to locate the edges of lofted aerosol layers. Using fundamentals of linear system theory, this study shows the deep link existing between the gradient method and the wavelet correlation transform method using the Haar wavelet, the latter being equivalent to the gradient method applied to a range-corrected signal profile smoothed by a low-pass spatial filtering, which seems not to have been explicitly noted in the literature so far. Consequences are readily drawn for the wavelet correlation transform method using other wavelets.

  • Atmospheric aerosol measurement with a network of advanced lidar instruments

     Comeron Tejero, Adolfo; Sicard, Michaël; Rocadenbosch Burillo, Francisco; Muñoz Porcar, Constantino; Rodriguez Gomez, Alejandro Antonio; Garcia Vizcaino, David
    SPIE Newsroom
    p. 1-3
    DOI: 10.1117/2.1201303.004693
    Date of publication: 2013-03-11
    Journal article

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    A European network of atmosphere sensors uses multi-wavelength elastic-Raman lidar instruments in its infrastructure.

    A European network of atmosphere sensors uses multi-wavelength elastic-Raman lidar instruments in its infrastructure.

  • Observación lidar atmosférica multi-espectral, procesado de la señal y recuperación de productos de datos: red europea y cal/val de satélites

     Comeron Tejero, Adolfo; Sicard, Michaël; Muñoz Porcar, Constantino; Garcia Vizcaino, David; Lange, Diego; Frasier, Steve; Rocadenbosch Burillo, Francisco
    Competitive project

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  • Determination of the overlap factor and its enhancement for medium-size tropospheric lidar systems: a ray-tracing approach

     Kumar, Dhiraj; Rocadenbosch Burillo, Francisco
    Journal of applied remote sensing
    Vol. 7, num. 1, p. 073591-1-073591-14
    DOI: 10.1117/1.JRS.7.073591
    Date of publication: 2013-01-31
    Journal article

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    he problem of overlap factor (OVF) computation and its near-range sensitivity for medium-size aperture (f/10, f/11) bi-axial tropospheric lidar systems using ray-tracing simulation software is presented. The method revisits both detector and fiber optics coupling alternatives at the telescope focal-plane along with the insertion of a field lens. A sensitivity analysis is carried out as a function of laser divergence, field lens, and detector/fiber positions, detector size, and the fiber's core diameter and numerical aperture. The ray-tracing approach presented here is straightforward and a comparatively much simpler solution than analytical-based methods. Parametric simulations are carried out to show that both approaches are coincident. Insertion of a field lens proves to be an elegant and low sensitivity solution for OVF enhancement, particularly, in the near-range of the lidar. (C) 2013 Society of Photo-Optical Instrumentation Engineers (SPIE)

    The problem of overlap factor (OVF) computation and its near-range sensitivity for medium-size aperture ( f ∕ 10 , f ∕ 11 ) bi-axial tropospheric lidar systems using ray-tracing sim- ulation software is presented. The method revisits both detector and fiber optics coupling alter- natives at the telescope focal-plane along with the insertion of a field lens. A sensitivity analysis is carried out as a function of laser divergence, field lens, and detector/fiber positions, detector size, and the fiber ’ s core diameter and numerical aperture. The ray-tracing approach presented here is straightforward and a comparatively much simpler solution than analytical-based meth- ods. Parametric simulations are carried out to show that both approaches are coincident. Insertion of a field lens proves to be an elegant and low sensitivity solution for OVF enhancement, par- ticularly, in the near-range of the lidar

  • Sistema de estabilización para la compensación del movimiento angular en plataformas LIDAR móviles

     Rocadenbosch Burillo, Francisco; Tiana Alsina, Jordi; Bermejo Sanchez, Sergio; Vall-llossera Ferran, Mercedes Magdalena; Camps Carmona, Adriano Jose
    Date of request: 2013-07-22
    Invention patent

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  • Parameter design of a biaxial lidar ceilometer

     Gregorio López, Eduard; Rocadenbosch Burillo, Francisco; Tiana Alsina, Jordi; Comeron Tejero, Adolfo; Sanz Cortiella, Ricardo; Rosell Polo, Joan Ramon
    Journal of applied remote sensing
    Vol. 6, num. 1, p. 063546-1-063546-19
    DOI: 10.1117/1.JRS.6.063546
    Date of publication: 2012-07-11
    Journal article

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  • Initial Training on Atmospheric Remote Sensing

     Baldasano Recio, Jose M.; Gassó Domingo, Santiago; Tiana Alsina, Jordi; Saeed, Umar; Banks, Robert Franklin; Rocadenbosch Burillo, Francisco
    Competitive project

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  • Participación española en ChArMEx (The Chemistry-Aerosol Mediterranean Experiment) ChArMEx-SP2

     Comeron Tejero, Adolfo; Baldasano Recio, Jose M.; Rocadenbosch Burillo, Francisco; Sicard, Michaël
    Competitive project

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  • Concept Design, Analysis, and Integration of the New U.P.C. Multispectral Lidar System  Open access

     Kumar, Dhiraj
    Department of Signal Theory and Communications, Universitat Politècnica de Catalunya
    Theses

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    The increasing need for range-resolved aerosol and water-vapour atmospheric observation networks worldwide has given rise to multi-spectral LIDARs (Light Detection and Ranging, a synonym of laser radar) as advanced remote sensing sensors. This Ph.D. presents the design, integration and analysis of the new 6-channel multispectral elastic/Raman LIDAR for aerosol and water-vapour content monitoring developed at the Remote Sensing Lab. (RSLAB) of the Universitat Politècnica de Catalunya (UPC). It is well known that the combination of at least three elastic and two Raman nitrogen channels are sufficient to enable retrieval of the optical and microphysical properties of aerosols with a key impact on climate change variables. The UPC lidar is part of the EARLINET (European Aerosol Research Lidar Network) -GALION (Global Atmospheric Watch Atmospheric Lidar Observation Network), a ground-based continental network including more than 28 stations. Currently, only 8 of the 28 EARLINET stations are of such advanced type. This Ph.D. specifically focuses on: (1) Concept link-budget instrument design and overlap factor assessment. The former includes opto-atmospheric parameter modelling and assessment of backscattered power and SNR levels, and maximum system range for the different reception channels (3 elastic, and 2 aerosol and 1 water-vapour Raman channels, ultraviolet to near-infrared bands). The latter studies the laser-telescope crossover function (or overlap function) by means of a novel ray-tracing Gaussian model. The problem of overlap function computation and its near-range sensitivity for medium size aperture (f/10, f/11) bi-axial tropospheric lidar systems using both detector and fiber-optics coupling alternatives at the telescope focal-plane is analysed using this new ray-tracing approach, which provides a much simpler solution than analytical-based methods. Sensitivity to laser divergence, field-lens and detector/fiber positions, and fiber¿s numerical aperture is considered. (2) Design and opto-mechanical implementation of the 6-channel polychromator (i.e., the spectrally selective unit in reception). Design trade-offs concerning light collimation, end-to-end transmissivity, net channel responsivity, and homogeneous spatial light distribution onto the detectors¿ active area discussed. (3) System integration and validation. This third part is two fold: On one hand, first-order backscatter-coefficient error bounds (a level-1 data product) for the two-component elastic lidar inversion algorithm are estimated for both random (observation noise) and systematic error sources (user¿s uncertainty in the backscatter-coefficient calibration, and user¿s uncertainty in the aerosol extinction-to-backscatter lidar ratio). On the other hand, the multispectral lidar so far integrated is described at both hardware and control software level. Statistical validation results for the new UPC lidar (today in routine operation) in the framework of SPALI-2010 intercomparison campaign are presented as part of EARLINET quality assurance / optimisation of instruments¿ program. The methodology developed in the first part of this Ph.D. has successfully been applied to the specification case study of the IFAE/UAB lidar system, which will be installed and operated at the Cherenkov Telescope Array (CTA) observatory. Finally, specs for automated unmanned unattended lidar operation with service times close to 365/24 are presented at the end of this Ph.D. in response to the increasing demand for larger observation times and availability periods of lidar stations.

  • Lidar remote sensing of pesticide spray drift

     Gregorio Lopez, Eduard
    Department of Signal Theory and Communications, Universitat de Lleida (UdL)
    Theses

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  • Backscatter error bounds for the elastic lidar two-component inversion algorithm

     Rocadenbosch Burillo, Francisco; Frasier, S.; Kumar, Dhiraj; Lange Vega, Diego; Gregorio López, Eduard; Sicard, Michaël
    IEEE transactions on geoscience and remote sensing
    Vol. 50, num. 11, p. 4791-4803
    DOI: 10.1109/TGRS.2012.2194501
    Date of publication: 2012-11
    Journal article

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    Total backscatter-coefficient inversion error bounds for the two-component lidar inversion algorithm (so-called Fernald's or Klett-Fernald-Sasano's method) are derived in analytical form in response to the following three error sources: 1) the measurement noise; 2) the user uncertainty in the backscatter-coefficient calibration; and 3) the aerosol extinction-to-backscatter ratio. The following two different types of error bounds are presented: 1) approximate error bounds using first-order error propagation and 2) exact error bounds using a total-increment method. Both error bounds are formulated in explicit analytical form, which is of advantage for practical physical sensitivity analysis and computational implementation. A Monte Carlo approach is used to validate the error bounds at 355-, 532-, and 1064-nm wavelengths.

    Total backscatter-coefficient inversion error bounds for the two-component lidar inversion algorithm (so-called Fernald's or Klett-Fernald-Sasano's method) are derived in analytical form in response to the following three error sources: 1) the measurement noise; 2) the user uncertainty in the backscatter-coefficient calibration; and 3) the aerosol extinction-to-backscatter ratio. The following two different types of error bounds are presented: 1) approximate error bounds using first-order error propagation and 2) exact error bounds using a total-increment method. Both error bounds are formulated in explicit analytical form, which is of advantage for practical physical sensitivity analysis and computational implementation. A Monte Carlo approach is used to validate the error bounds at 355-, 532-, and 1064-nm wavelengths.

  • Intense dust and extremely fresh biomass burning outbreak in Barcelona, Spain: Characterization of their optical properties and estimation of their direct radiative forcing

     Sicard, Michaël; Mallet, Maëlle; Garcia Vizcaino, David; Comeron Tejero, Adolfo; Rocadenbosch Burillo, Francisco; Dubuisson, P.; Muñoz Porcar, Constantino
    Environmental research letters
    Vol. 7, num. 3, p. 2-7
    DOI: 10.1088/1748-9326/7/3/034016
    Date of publication: 2012-07
    Journal article

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    Study of the correlation between columnar aerosol burden, suspended matter at ground and chemical components in a background European environment  Open access

     Estelles, Victor; Martínez Lozano, José Antonio; Pey, J.; Sicard, Michaël; Querol, Xavier; Esteve, A.R.; Utrillas Esteban, Maria Pilar; Sorribas, M.; Gangoiti, G.; Alastuey, A.; Rocadenbosch Burillo, Francisco
    Journal of geophysical research
    Vol. 117, num. 43, p. 1-14
    DOI: 10.1029/2011JD016356
    Date of publication: 2012
    Journal article

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    Although routinely monitored by ground based air quality networks, the particulate matter distribution could be eventually better described with remote sensing techniques. However, valid relationships between ground level and columnar ground based quantities should be known beforehand. In this study we have performed a comparison between particulate matter measurements at ground level at different cut sizes (10, 2.5 and 1.0 mm), and the aerosol optical depth obtained by means of a ground based sunphotometer during a multiinstrumental field campaign held in El Arenosillo (Huelva, Spain) from 28 June to 4 July 2006. All the PM fractions were very well correlated with AOD with correlation coefficients that ranged from 0.71 to 0.81 for PM10, PM2.5 and PM1. Furthermore, the influence of the mixing layer height in the correlations was explored. The improvement in the correlation when the vertical distribution is taken into account was significant for days with a homogeneous mixing layer. Moreover, the chemical analysis of the individual size fractions allowed us to study the origin of the particulate matter. Secondary components were the most abundant and also well correlated in the three size fractions; but for PM10 fraction, chemical species related to marine origin were best correlated. Finally, we obtained a relationship between MODIS L3 AOD from collection 5.1 and the three PM cut sizes. In spite of being a relatively clean environment, all the techniques were able to capture similar day to day variations during this field campaign.

  • Study on aerosol properties over Madrid (Spain) by multiple instrumentation during SPALI10 lidar campaign

     Molero, Francisco; Sicard, Michaël; Navas Guzmán, Francisco; Preissler, J.; Freudenthaler, Volker; Fernández, J.A.; Amodeo, Aldo; Tomás Martinez, Sergio; Mattis, I.; Granados, M; Giunta, Aldo; Pujadas Cordero, Manuel; Lange, Diego; Wagner, F.; Comeron Tejero, Adolfo; Alados Arboledas, Lucas; Guerrero Rascado, Juan Luis; D'Amico, Giuseppe; Kumar, Dhiraj; Giner Nos, Joaquin Jose; Muñoz Porcar, Constantino; Rocadenbosch Burillo, Francisco; Pappalardo, Gelsomina
    Óptica pura y aplicada
    Vol. 45, num. 4, p. 405-413
    DOI: 10.7149/OPA.45.4.405
    Date of publication: 2012-11-19
    Journal article

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    Cuatro sistemas lidar Raman multifrecuencia (Madrid, Granada, Barcelona y Evora), tomaron medidas simultáneamente a un sistema de referencia (Potenza) para verificar su funcionamiento durante la campaña de intercomparación: SPALI10, (SPAin Lidar Intercomparison 2010) que tuvo lugar en Madrid entre el 18 de Octubre y el 5 de Noviembre de 2010. Estos sistemas lidar Raman multifrecuencia proporcionan propiedades ópticas de los aerosoles con resolución vertical. Los perfiles suministrados por los sistemas lidar se compararon con información complementaria proporcionada por otra instrumentación, tal como la distribución de tamaños de los aerosoles medida de manera continua a nivel de superficie o la caracterización de la columna de aerosoles

  • Backscattered signal level and SNR validation methodology for tropospheric elastic lidars

     Lange, Diego; Kumar, Dhiraj; Rocadenbosch Burillo, Francisco
    IEEE International Geoscience and Remote Sensing Symposium
    p. 4707-4710
    DOI: 10.1109/IGARSS.2012.6350414
    Presentation's date: 2012-07
    Presentation of work at congresses

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    A methodology aimed at validating elastic-channel optical power return and signal-to-noise ratio (SNR) levels estimated at the link-budget design stage of a tropospheric lidar against the measured ones is presented. A Rayleigh fit along with knowledge of the atmospheric aerosol transmittance and emission energy is used to theoretically estimate the net voltage responsivity. As a further refinement, when simultaneous analog and photon-counting acquisition is available, the method formulates a rough estimate of the optical losses in the receiving chain.

    A methodology aimed at validating elastic-channel optical power return and signal-to-noise ratio (SNR) levels estimated at the link-budget design stage of a tropospheric lidar against the measured ones is presented. A Rayleigh fit along with knowledge of the atmospheric aerosol transmittance and emission energy is used to theoretically estimate the net voltage responsivity. As a further refinement, when simultaneous analog and photon-counting acquisition is available, the method formulates a rough estimate of the optical losses in the receiving chain. Preliminary validation of the link-budget-assessed optical power and SNR levels for the 1064-nm channel of the Remote Sensing Lab. (RSLab) lidar is discussed.

  • Utilization of a field lens to improve the overlap function in lidar systems using optical fibers

     Comeron Tejero, Adolfo; Sicard, Michaël; Kumar, Dhiraj; Rocadenbosch Burillo, Francisco; Lange Vega, Diego
    International Laser Radar Conference
    p. 129-132
    Presentation's date: 2012-06-26
    Presentation of work at congresses

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  • Power budget and performance assessment for the RSLAB multispectral elastic/raman lidar system

     Kumar, Dhiraj; Lange, Diego; Rocadenbosch Burillo, Francisco; Tomas, Sergio; Sicard, Michaël; Muñoz Porcar, Constantino; Comeron Tejero, Adolfo
    IEEE International Geoscience and Remote Sensing Symposium
    p. 4703-4706
    DOI: 10.1109/IGARSS.2012.6350415
    Presentation's date: 2012
    Presentation of work at congresses

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    The need of a multi-spectral lidar has widely been experienced in last few years with a view to invert the optical and microphysical properties of aerosols and their impact on the climate change. As a part of the EARLINET-GALION objectives, a joint effort has already been made by the European Aerosol Research Lidar Network (EARLINET). The EARLINET advanced standard of 3+2-channel configuration for lidar instruments (3+2 standing for 3 elastic channels and 2 respective Raman channels) enables retrieval of aerosol microphysical properties. An overview of the new RSLAB 3+2+1 multispectral lidar system, therefore, is presented in terms of power budget estimation for all the reception channels and overall system performance, that is, signal-to-noise ratio (SNR) and maximum sounding range achieved.

  • Q-00002

     Tiana Alsina, Jordi; Bermejo Sanchez, Sergio; Vall-llossera Ferran, Mercedes Magdalena; Camps Carmona, Adriano Jose; Rocadenbosch Burillo, Francisco
    Competitive project

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  • Aerosols, Clouds and Trace Gases Research Infrastructure Network

     Rocadenbosch Burillo, Francisco; Sicard, Michaël; Muñoz Porcar, Constantino; Garcia Vizcaino, David; Rodriguez Gomez, Alejandro Antonio; Lange Vega, Diego; Kumar, Dhiraj; Comeron Tejero, Adolfo
    Competitive project

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  • CONTRIBUTION OF ELASTIC-BACKSCATTER LIDARS TO WIND FIELD RETRIEVAL AND ATMOSPHERIC BOUNDARY LAYER MONITORING

     Tomas Martinez, Sergio
    Department of Signal Theory and Communications, Universitat Politècnica de Catalunya
    Theses

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  • SPALINET: The Spanish and Portuguese aerosol lidar network

     Sicard, Michaël; Pujadas Cordero, Manuel; Alados Arboledas, Lucas; Pedrós Esteban, Roberto; Díaz, Juan Pedro; Córdoba Jabonero, Carmen; Requena, Alberto; Comeron Tejero, Adolfo; Rocadenbosch Burillo, Francisco; Rodrigues, Jose António; Moreno, J. M.; Wagner, F.
    Óptica pura y aplicada
    Vol. 44, num. 1, p. 1-5
    Date of publication: 2011-02-01
    Journal article

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    To extend and reinforce the action of the European network EARLINET (supported by the EARLINET-ASOS European project), a network of Spanish and Portuguese aerosol lidars (SPALINET) was created. In the first three years of the project six out of the ten systems have been successfully intercompared, seven elastic algorithms and six Raman algorithms have also been validated. Now the network focuses on future scientific objectives aiming at performing coordinated measurements. This paper presents the scientific context and a description of the network, as well as the results from the first three years of activity.

  • Aerosol closure study by lidar, Sun photometry, and airborne optical counters during DAMOCLES filed campaign at El Arenosillo sounding station, Spain

     Guerrero-Rascado, Juan Luis; Andrey, J.; Sicard, Michaël; Comeron Tejero, Adolfo; Pujadas Cordero, Manuel; Molero, Francisco; Rocadenbosch Burillo, Francisco; Pedrós Esteban, Roberto; Serrano-Vargas, O.; Gil Ojeda, Manuel; Olmo, F. J.; Lyamani, H.; Navas Guzmán, Francisco; Alados Arboledas, Lucas
    Journal of geophysical research
    Vol. 116, num. D02209, p. 1-14
    DOI: 10.1029/2010JD014510
    Date of publication: 2011-01-26
    Journal article

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  • Use of a field lens for improving the overlap function of a lidar system employing an optical fiber in the receiver assembly

     Comeron Tejero, Adolfo; Sicard, Michaël; Kumar, Dhiraj; Rocadenbosch Burillo, Francisco
    Applied optics
    Vol. 50, num. 28, p. 5538-5544
    DOI: 10.1364/AO.50.005538
    Date of publication: 2011-10-01
    Journal article

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  • Seasonal variability of aerosol optical properties observed by means of a Raman lidar at an EARLINET site over Northeastern Spain

     Sicard, Michaël; Rocadenbosch Burillo, Francisco; Md. Reba, Mohd Nadzri; Comeron Tejero, Adolfo; Tomas Martinez, Sergio; Garcia Vizcaino, David; Batet Torrell, Oscar; Barrios Porras, Ricardo Alfonso; Kumar, Dhiraj; Baldasano Recio, Jose M.
    Atmospheric chemistry and physics
    Vol. 11, p. 175-190
    DOI: 10.5194/acp-11-175-2011
    Date of publication: 2011-01-11
    Journal article

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    Monitoring of the Eyjafjallajökull volcanic aerosol plume over the Iberian Peninsula by means of four EARLINET lidar stations  Open access

     Sicard, Michaël; Guerrero Rascado, Juan Luis; Navas Guzmán, Francisco; Preissler, J.; Molero, Francisco; Tomas Martinez, Sergio; Bravo Aranda, J. A.; Comeron Tejero, Adolfo; Rocadenbosch Burillo, Francisco; Wagner, F.; Pujadas Cordero, Manuel; Alados Arboledas, Lucas
    Atmospheric chemistry and physics discussions
    Vol. 11, num. 11, p. 29681-29721
    DOI: 10.5194/acpd-11-29681-2011
    Date of publication: 2011
    Journal article

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    Lidar and sun-photometer measurements were performed intensively over the Iberian Peninsula (IP) during the eruption of Eyjafjallaj ¨ okull volcano (Iceland) in April–May 2010. The volcanic plume hit all the IP stations for the first time on 5 May 2010. A thorough study of the event is conducted for the period 5–8 May. Firstly the spatial and temporal evolution of the plume is described by means of lidar and sun-photometer measurements supported with backtrajectories. The volcanic aerosol layers observed over the IP were rather thin (< 1000 m) with a top height up to 11–12 km. The mean optical thicknesses associated to those layers were rather low (between 0.013 and 0.020 over the whole period). Punctually on 7 May the optical thickness reached peak values near 0.10. Secondly the volcanic aerosols are characterized in terms of extinction and backscatter coefficients, lidar ratios, A° ngstro¨m exponents and linear particle depolarization ratio. Lidar ratios at different sites varied between 30 and 50 sr without a marked spectral dependency. Similar extinction-related A° ngstro¨m exponents varying between 0.6 and 0.8 were observed at different sites. The temporal evolution of the backscatter-related A° ngstro¨m exponents points out a possible decrease of the volcanic particle size as the plume moves from west to east. Particle depolarization ratios on the order of 0.06–0.08 confirmed the coexistence of both ash and non-ash particles. Additionally profiles of mass concentration were obtained with a method using the opposite depolarizing effects of ash particles (strongly depolarizing) and non-ash particles (very weakly depolarizing), and sun-photometer observations. In Granada the ash mass concentration was found approximately 1.5 higher than that of non-ash particles, and probably did not exceed the value of 200 μgm−3 during the whole event.

  • Optimised data-gluing method for mixed analog/photon-counting lidar signals

     Lange, Diego; Kumar, Dhiraj; Rocadenbosch Burillo, Francisco; Sicard, Michaël; Comeron Tejero, Adolfo
    Workshop on Lidar Measurements in Latin America
    p. 4-6
    Presentation's date: 2011-09-26
    Presentation of work at congresses

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    In atmospheric LIDAR (Light Detection and Ranging) remote sensing, the dynamic range of the return power signals can span up to five orders of magnitude. Modern acquisition systems such as those based on LicelTM transient recorders combine a dual acquisition mode in which the return signal is recorded simultaneously in both analog (analog-to-digital (AD) conversion) and photon-counting (PC) modes. Although both data records can be analyzed separately, their combination obtained through gluing gives the advantage of the high linearity of the AD conversion for high light-level signals (especially in the near range) and the high sensitivity of the PC mode for low light-level signals (in the far range). Recently, eruptions of volcanoes such as Eyjafjalla (Iceland) in 2010, Grímsvötn (Iceland Puyehue (Argentina) Nabro (Eritrea) and Mount Lokon (Indonesia) in 2011 have yielded emergency situations with a strong economical cost due to human evacuation and/or air traffic interruption. Volcanic aerosols are first injected in the troposphere and often reach the stratosphere where they can reside for several years. The mixed analog/photo-counting acquisition approach is particularly suitable for the detection of volcanic aerosols in both the troposphere (near/mid range) and the stratosphere (far range). In this line, a case study showing volcanic aerosols from the Nabro volcano (Eritrea, 2011) in the stratosphere and simultaneously Saharan dust in the troposphere over the multi-spectral Barcelona lidar station during the period 27 June ¿ 1 July 2011 is presented. The benefits of the proposed gluing technique will be shown through the comparison of analog, PC, and glued backscatter-coefficient time series. Existing gluing algorithms solve the fitting coefficients by matching both analog and PC data over a predefined spatial range (or equivalently, over a predefined upper and lower counting rate) depending on which kind of photodetector (usually a photomultiplier) is being used. In this work, an enhanced data-gluing formulation is presented. The method automatically finds the spatial range where both analog and PC signals are more similar based on Euclidian distance minimization over piece-wise range intervals along the whole acquisition spatial range.

  • Wind speed and turbulence estimation with a backscatter lidar at a single line of sight

     Tomás, Sergio; Sicard, Michaël; Rocadenbosch Burillo, Francisco
    Remote Sensing for Agriculture, Ecosystems, and Hydrology
    p. 817703-1-817703-8
    DOI: 10.1117/12.898106
    Presentation's date: 2011-09
    Presentation of work at congresses

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    Six-channel polychromator design and implementation for the UPC elastic/Raman LIDAR  Open access

     Kumar, Dhiraj; Rocadenbosch Burillo, Francisco; Sicard, Michaël; Comeron Tejero, Adolfo; Lange, Diego; Muñoz, Constantino; Tomás, Sergio; Gregorio, Eduard
    SPIE International Symposium - Remote Sensing Europe
    p. 81820W-1-81820W-10
    DOI: 10.1117/12.896305
    Presentation's date: 2011-09-21
    Presentation of work at congresses

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    A 6-channel dichroic-based polychromator is presented as the spectrally selective unit for the U.P.C. elastic/Raman lidar. Light emission is made at 355-nm (ultraviolet, UV), 532-nm (visible, VIS) and 1064-nm (near infrared, NIR) wavelengths. In reception, the polychromator is the spectral separation unit that separates the laser backscattered composite return into 3 elastic (355, 532, 1064-nm wavelengths) and 3 Raman channels (386.7, 607.4 and 407.5-nm (water-vapor) wavelengths). The polychromator houses photo-multiplier tubes (PMT) for all the channels except for the NIR one, which is avalanche photodiode (APD) based. The optomechanical design uses 1-inch optics and Eurorack standards. The APD-based receiver uses a XY-axis translation/elevation micro-positioning stage due to its comparatively small active area and motorised neutral density filters are used in all PMT-based channels to avoid detector saturation. The design has been specially optimized to provide homogeneous spatial light distribution onto the photodetectors and good mechanical repeatability. All channels are acquired in mixed analog and photon-counting mode using Licel® transient recorders, which are controlled by means of a user friendly LabVIEW TM interface. The paper focuses on the main polychromator optical design parameters, that is, light collimation trade-offs, end-to-end transmissivity, net channel responsivity, light distribution and spot size onto the photodetectors. The polychromator along with the rest of the U.P.C. lidar system has successfully been tested during a recent lidar system intercomparison campaign carried out in Madrid (Spain) during Oct. 2010.

  • Wind speed and direction measurements with a backscatter lidar using the auto-correlation contour analysis

     Tomás, Sergio; Sicard, Michaël; Rocadenbosch Burillo, Francisco
    Remote Sensing for Agriculture, Ecosystems, and Hydrology
    p. 817702-1-817702-13
    DOI: 10.1117/12.898096
    Presentation's date: 2011-09
    Presentation of work at congresses

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    A method to estimate wind velocity using the backscatter lidar signals of transported aerosol particles is presented. The lidar signal is correlated along range and time dimensions for each line of sight in which the lidar is pointing. The method is based on the analysis of contours of these range-time auto-correlation functions. This analysis obtains ellipse curve parameters which are related to the radial velocity and to the square wind speed, locally retrieved for a given line of sight. The combination of data from several angular positions enables the wind direction retrieval. Two possible implementations of the method are considered and tested with an actual measurement with the lidar of the Universitat Politècnica de Catalunya (UPC).

  • Airborne spray drift measurement using passive collectors and lidar Systems

     Gregorio, Eduard; Solanelles, Francesc; Rocadenbosch Burillo, Francisco; Rosell Amigo, Juan Ramon; Sanz, Ricardo
    Remote Sensing for Agriculture, Ecosystems, and Hydrology
    p. 81741I-81741I-12
    DOI: 10.1117/12.903723
    Presentation's date: 2011
    Presentation of work at congresses

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    Minimization of the risk associated with spray applications requires a proper understanding of the spray drift phenomenon. This fact has led to the development of several techniques to measure the deposition on horizontal surfaces as well as the airborne spray profiles. Assessment of airborne spray drift is particularly difficult because this phenomenon is subject to variable micrometeorological conditions. However the monitoring of airborne drift has a great importance since it can be carried over long distances. This paper reviews main sampling techniques currently used to asses the airborne spray drift, based on passive collectors and tracers. Theoretical principles that determine the efficiency of passive samplers are studied as well as the performance of different types of tracers. On the other hand, this paper shows new airborne spray drift assessment techniques based on lidar technology, reviewing its principle of operation as well as its practical application in several spray drift trials. It is concluded that the lidar technique has significant advantages over conventional methods, especially in terms of time consumption and monitoring capabilities. However, the future adoption of lidar technology for airborne spray drift studies will be subjected to the development of lidar instruments really adapted to this application.

  • Best IEEE Reviewer

     Rocadenbosch Burillo, Francisco
    Award or recognition

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  • LIDARES ELASTICO-RAMAN: Integracion,procesado de datos y explotacion

     Comeron Tejero, Adolfo; Muñoz Porcar, Constantino; Sicard, Michaël; Garcia Vizcaino, David; Tomas Martinez, Sergio; Kumar, Dhiraj; Lange Vega, Diego; Rocadenbosch Burillo, Francisco
    Competitive project

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    Atmospheric boundary-layer height estimation by adaptive Kalman filtering of lidar data  Open access

     Tomas Martinez, Sergio; Rocadenbosch Burillo, Francisco; Sicard, Michaël
    Remote Sensing for Agriculture, Ecosystems, and Hydrology
    p. 782704-1-782704-10
    DOI: 10.1117/12.866477
    Presentation's date: 2010-09-20
    Presentation of work at congresses

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    A solution based on a Kalman filter to trace the evolution of the atmospheric boundary layer (ABL) sensed by an elastic backscatter lidar is presented. An erf-like profile is used to model the mixing layer top and the entrainment zone thickness. The extended Kalman filter (EKF) enables to retrieve and track the ABL parameters based on simplified statistics of the ABL dynamics and of the observation noise present in the lidar signal. This adaptive feature permits to analyze atmospheric scenes with low signal-to-noise ratios without need to resort to long time averages or rangesmoothing techniques, as well as to pave the way for an automated detection method. First EKF results based on synthetic lidar profiles are presented and compared with a typical least-squares inversion for different SNR scenarios.

  • Participación Española en Charmex (The Chemistry-Aerosol Mediterranean Experiment)

     Rocadenbosch Burillo, Francisco; Baldasano Recio, Jose M.; Comeron Tejero, Adolfo; Sicard, Michaël
    Competitive project

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  • Unmanned unattended LIDAR (radar laser) station

     Comeron Tejero, Adolfo; Muñoz Porcar, Constantino; Sicard, Michaël; Garcia Vizcaino, David; Rocadenbosch Burillo, Francisco
    Competitive project

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  • Data processing and Inversion interfacing the UPC elastic-Raman LIDAR system

     Md. Reba, Mohd Nadzri
    Department of Signal Theory and Communications, Universitat Politècnica de Catalunya
    Theses

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  • Lidar measurements of wind velocity fields

     Comeron Tejero, Adolfo; Muñoz Porcar, Constantino; Rocadenbosch Burillo, Francisco; Rodriguez Gomez, Alejandro Antonio; Sicard, Michaël; Tomas Martinez, Sergio
    Date of publication: 2010
    Book chapter

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    Seasonal variability of aerosol optical properties observed by means of an elastic-Raman lidar over Northeastern Spain  Open access

     Sicard, Michaël; Md. Reba, Mohd Nadzri; Rocadenbosch Burillo, Francisco; Comeron Tejero, Adolfo; Tomás Martinez, Sergio; Garcia Vizcaino, David; Batet Torrell, Oscar; Barrios Porras, Ricardo Alfonso; Kumar, Dhiraj
    Atmospheric chemistry and physics discussions
    Vol. 10, p. 14053-14094
    DOI: 10.5194/acpd-10-14053-2010
    Date of publication: 2010-06-01
    Journal article

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    The annual and seasonal variability of aerosol optical properties observed by means of an elastic-Raman lidar over Northeastern Spain has been assessed. The lidar representativeness has first been checked against un-photometer measurements in terms of aerosol optical thickness. Then the annual cycle and the seasonal variability of the planetary boundary layer aerosol optical thickness and its fraction compared to the columnar optical thickness, the lidar ratio, the backscatter-related A° ngstro¨m exponent and the planetary boundary layer height have been analyzed and discussed. Winter and summer mean profiles of extinction, backscatter and lidar ratio retrieved with the Raman algorithm have been presented. The analysis shows the impact of most of the natural events (Saharan dust intrusions, wildfires, etc.) and meteorological situations (summer anticyclonic situation, the formation of the Iberian thermal low, winter longrange transport from North Europe and/or North America, re-circulation flows, etc.) occurring in the Barcelona area. A detail study of a special event including a combined intrusion of Saharan dust and biomass-burning particles has proven the suitability of combining nighttime Raman- and daytime pure elastic-inversions to discriminate spatially different types of aerosols and to follow their spatial and temporal evolution.

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    Practical analytical backscatter errorbars for the elastic one-component liar inversion algorithm  Open access

     Rocadenbosch Burillo, Francisco; Md. Reba, Mohd Nadzri; Sicard, Michaël; Comeron Tejero, Adolfo
    Applied optics
    Vol. 49, num. 17, p. 3380-3393
    Date of publication: 2010-06-10
    Journal article

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  • Site-testing using an aerosol, backscatter lidar at the Roque de los Muchachos Observatory

     Sicard, Michaël; Md. Reba, Mohd Nadzri; Tomas Martinez, Sergio; Comeron Tejero, Adolfo; Batet Torrell, Oscar; Muñoz Porcar, Constantino; Rodriguez Gomez, Alejandro Antonio; Rocadenbosch Burillo, Francisco; Muñoz Tuñón, Casiana; Jiménez Fuensalida, Jesús
    Monthly notices of the Royal Astronomical Society
    Vol. 405, num. 1, p. 129-142
    DOI: 10.1111/j.1365-2966.2010.16468.x
    Date of publication: 2010-06-01
    Journal article

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  • EARLINET correlative measurements for CALIPSO: first intercomparison results

     Pappalardo, Gelsomina; Hiebsch, Anja; Ansmann, Albert; Seifert, Patric; Linné, Holger; Mona, Lucia; Alados Arboledas, Lucas; Apituley, Arnoud; Balis, Dimitris; Chaikovsky, Anatoli; D'Amico, Giuseppe; Amodeo, Aldo; Giunta, Aldo; Freudenthaler, Volker; Giannakaki, E.; Grigorov, I. Ivan; Iarlori, M.; Madonna, Fabio; Mamouri, R.E.; Papayannis, Alexander; Nasti, Libera; Mattis, I.; Pietruczuk, Aleksander; Pujadas Cordero, Manuel; Rocadenbosch Burillo, Francisco; Rizi, Vicenzo; Russo, Felicita; De Tomasi, Ferdinando; Schnell, Franziska; Spinelli, N.; Wandinger, Ulla; Wang, Xuan; Wiegner, M.
    Journal of geophysical research
    Vol. 115, num. D00H19, p. 1-21
    DOI: 10.1029/2009JD012147
    Date of publication: 2010-04-15
    Journal article

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    Climatology of the aerosol extinction to backscatter ratio from sun photometric measurements  Open access

     Pedrós Esteban, Roberto; Estallés, Víctor; Sicard, Michaël; Gómez Amo, Jose Luis; Utrillas Esteban, Maria Pilar; Martínez Lozano, José Antonio; Rocadenbosch Burillo, Francisco; Pérez, C.; Baldasano Recio, Jose M.
    IEEE transactions on geoscience and remote sensing
    Vol. 48, num. 1, p. 237-249
    DOI: 10.1109/TGRS.2009.2027699
    Date of publication: 2010-01-01
    Journal article

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    The elastic lidar equation contains two unknown atmospheric parameters, namely, the particulate optical extinction and backscatter coefficients, which are related through the lidar ratio (i.e., the particulate-extinction-to-backscatter ratio). So far, independent inversion of the lidar signal has been carried out by means of Raman lidars (usually limited to nighttime measurements), high-spectral-resolution lidars, or scanning elastic lidars under the assumption of a homogeneously vertically stratified atmosphere. In this paper, we present a procedure to obtain the lidar ratio at 532 nm by a combined Sunphotometer– aerosol-model inversion, where the viability of the solution is largely reinforced by assimilating categorized air-mass back-trajectory information. Thus, iterative lidar-ratio tuning to reconstruct the Sun-photometric aerosol optical depth (AOD) is additionally constrained by the air-mass back trajectories provided by the hybrid single-particle Lagrangian integratedtrajectory model. The retrieved lidar ratios are validated with inversions of lidar data based on the Klett–Fernald–Sasano algorithm and with the Aerosol Robotic Network (AERONET)- retrieved lidar ratios. The estimated lidar ratios concur with the AERONET-retrieved lidar ratios and with those of the well-known KFS inversion constrained with Sun-photometric AOD values and embedded single-scattering models. The proposed method can be applied to routinely extract climatological values of the lidar ratio using measurements of direct solar irradiance (more numerous than those of sky radiance).

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    Long-term aerosol and cloud database from correlative EARLINET-CALIPSO observations  Open access

     Hiebsch, Anja; Wandinger, Ulla; Ansmann, Albert; Pappalardo, Gelsomina; Madonna, Fabio; D'Amico, Giuseppe; Mona, Lucia; Apituley, Arnoud; Giunta, Aldo; Linné, Holger; Mattis, I.; Serikov, I.; Wilson, K.; Alados Arboledas, Lucas; Navas Guzmán, Francisco; Balis, Dimitris; De Tomasi, Ferdinando; Giannakaki, E.; Chaikovsky, Anatoli; Freudenthaler, Volker; Wiegner, M.; Schnell, Franziska; Stoyanov, Dimitar Vassilev; Grigorov, I. Ivan; Rizi, Vicenzo; Iarlori, M.; Molero, Francisco; Mamouri, R.E.; Papayannis, Alexander; Pujadas Cordero, Manuel; Pietruczuk, Aleksander; Rocadenbosch Burillo, Francisco; Perrone, Maria-Rita; Tomás Martinez, Sergio; Kumar, Dhiraj; Spinelli, N.; Wang, Xuan
    International Laser Radar Conference
    p. 1241-1244
    Presentation's date: 2010-07-05
    Presentation of work at congresses

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    The European Aerosol Research Lidar Network, EARLINET, performs correlative observations during CALIPSO overpasses based on a sophisticated measurement strategy since June 2006. Within a dedicated activity supported by the European Space Agency (ESA), sixteen EARLINET stations contributed about 1500 measurements during an intensive observational period from May 2008 to October 2009. From these measurements, we establish a long-term aerosol and cloud database of correlative EARLINET-CALIPSO observations. This database shall provide a basis for homogenizing long-term space-borne observations conducted with different lidar instruments operating at different wavelengths on various platforms over the next decade(s). The database is also used to study the quality and representativeness of satellite lidar cross sections along an orbit against long-term lidar network observations on a continental scale.

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    Lidar ratio estimation using a two-point calibration in an turbid layer aloft  Open access

     Rocadenbosch Burillo, Francisco; Md. Reba, Mohd Nadzri; Sicard, Michaël; Tomas, Sergio; Kumar, Dhiraj
    International Laser Radar Conference
    p. 59-62
    Presentation's date: 2010-07
    Presentation of work at congresses

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    On the lidar ratio estimation from the synergy between aeronet sun-photometer data and elastic lidar inversion  Open access

     Md. Reba, Mohd Nadzri; Rocadenbosch Burillo, Francisco; Sicard, Michaël; Kumar, Dhiraj; Tomas, Sergio
    International Laser Radar Conference
    p. 1102-1105
    Presentation's date: 2010-07
    Presentation of work at congresses

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    Representativeness of aerosol measurements: EARLINET-CALIPSO correlative study  Open access

     Pappalardo, Gelsomina; Mona, Lucia; Hiebsch, Anja; Wandinger, Ulla; Apituley, Arnoud; Linné, Holger; Alados Arboledas, Lucas; Balis, Dimitris; Comeron Tejero, Adolfo; Freudenthaler, Volker; Giannakaki, E.; Giunta, Aldo; Guerrero, J. L.; Madonna, Fabio; Mamouri, R.E.; Mattis, I.; Papayannis, Alexander; Pujadas Cordero, Manuel; Rocadenbosch Burillo, Francisco; Spinelli, N.; Wang, Xuan; Wiegner, M.
    International Laser Radar Conference
    p. 883-886
    Presentation's date: 2010-07
    Presentation of work at congresses

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    The high variability of tropospheric aerosols, both in space and time, is the main cause of the high uncertainty about radiative forcing related to tropospheric aerosols and their interaction with clouds. Because of the lack of high resolution aerosol global vertical profiles, the vertical mixing has not been considered so far in studies of spatial and temporal variability. The CALIPSO mission provides the first opportunity to investigate the 4-D aerosol and cloud fields in detail. However, because of the CALIOP small footprint and the revisit time of 16 days, correlative ground-based lidar observations are necessary in order to investigate the representativeness of these satellite observations. EARLINET, the European Aerosol Research Lidar Network, started correlative measurements for CALIPSO in June 2006, right after the CALIPSO launch. An integrated study of CALIPSO and EARLINET correlative measurements opens new possibilities for spatial (both horizontal and vertical) and temporal representativeness investigation of polar-orbit satellite measurements also in terms of revisit time.

  • Seguimiento de las cenizas del Eyjafjalla sobre la Península Ibérica por la red de lidares hispano-portuguesa SPALINET

     Sicard, Michaël; Kumar, Dhiraj; Tomas Martinez, Sergio; Comeron Tejero, Adolfo; Rocadenbosch Burillo, Francisco; Guerrero-Rascado, Juan Luis; Molero, Francisco; Preissler, J.; Silva, A.M.; Navas Guzmán, Francisco; Pujadas Cordero, Manuel; Bravo Aranda, J. A.; Alados Arboledas, Lucas; Wagner, F.; Bolarín, Jose Miguel; Requena, Alberto
    Congreso Nacional del Medio Ambiente
    p. 10-17
    Presentation's date: 2010-11-22
    Presentation of work at congresses

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    La reciente erupción del volcán Eyjafjallajökull es una muestra – extremada, pero de probabilidad no despreciable – de la influencia que los aerosoles atmosféricos pueden tener en la vida diaria de miles de personas y en la economía mundial. Este acontecimiento ha sido seguido desde tierra por – entre otros instrumentos – radares láser (lidares) que han permitido determinar la evolución en el espacio y el tiempo de las nubes de ceniza proyectadas por el volcán y han proporcionado información de valor a las agencias meteorológicas y a las administraciones responsables de la seguridad de la navegación aérea.