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ABSTRACT: The elastic, two-component algorithm is the most common inversion method for retrieving the aerosol backscatter coefficient from ground- or space-based backscatter lidar systems. A quasi-analytical formulation of the statistical error associated to the aerosol backscatter coefficient caused by the use of real, noise-corrupted lidar signals in the two-component algorithm is presented. The error expression depends on the signal-to-noise ratio along the inversion path and takes into account "instantaneous" effects, the effect of the signal-to-noise ratio at the range where the aerosol backscatter coefficient is being computed, as well as "memory" effects, namely, both the effect of the signal-to-noise ratio in the cell where the inversion is started and the cumulative effect of the noise between that cell and the actual cell where the aerosol backscatter coefficient is evaluated. An example is shown to illustrate how the "instantaneous" effect is reduced when averaging the noise-contaminated signal over a number of cells around the range where the inversion is started.
Applied Optics 02/2009; 48(2):176-82. · 1.41 Impact Factor
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ABSTRACT: A lidar field campaign was performed between 30<sup>th</sup> June and 4<sup>th</sup> July 2007 in the Teide Observatory in the Canarian island of Tenerife to characterize the atmosphere of this astrophysical observation site in terms of nocturnal boundary layer height and wind fields. The nocturnal boundary layer height was found lower than 810 m in all cases and the aerosol optical thickness lower than 0.005 and 0.03 at 1064 and 532 nm, respectively. Wind fields could hardly be retrieved because of faint signals and very weak wind velocities observed during the campaign.
IEEE International Geoscience & Remote Sensing Symposium, IGARSS 2008, July 8-11, 2008, Boston, Massachusetts, USA, Proceedings; 01/2008
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ABSTRACT: The Lidar group in the Technical University of Catalonia is actively working in wind lidar techniques. An extensive review of such techniques is presented. A special emphasis is made on the direct Doppler technique and the direct motion technique with a lines-of-sight scanning pattern. Current developments are also mentioned.
IEEE International Geoscience & Remote Sensing Symposium, IGARSS 2008, July 8-11, 2008, Boston, Massachusetts, USA, Proceedings; 01/2008
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IEEE International Geoscience & Remote Sensing Symposium, IGARSS 2007, July 23-28, 2007, Barcelona, Spain, Proceedings; 01/2007
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ABSTRACT: The lidar data-inversion algorithm widely known as the Klett method (and its more elaborate variants) has long been used to invert elastic-lidar data obtained from atmospheric sounding systems. The Klett backward algorithm has also been shown to be robust in the face of uncertainties concerning the boundary condition. Nevertheless electrical noise at the photoreceiver output unavoidably has an impact on the data-inversion process, and describing in an explicit way how it affects retrieval of the atmospheric optical coefficients can contribute to improvement in inversion quality. We examine formally the way noise disturbs backscatter-coefficient retrievals done with the Klett backward algorithm, derive a mathematical expression for the retrieved backscatter coefficient in the presence of noise affecting the signal, and assess the noise impact and suggest ways to limit it.
Applied Optics 05/2004; 43(12):2572-7. · 1.41 Impact Factor
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