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Author: Freudenthaler, Volker × Publisher: Les Ulis : EDP Sciences ×

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    Raman LIDAR for UHECR experiments: an overview of the L'Aquila (Italy) lidar station experience for the retrieval of quality-assured data
    (Les Ulis : EDP Sciences, 2017) Iarlori, Marco; Rizi, Vincenzo; D’Amico, Giuseppe; Freudenthaler, Volker; Wandinger, Ulla; Grillo, Aurelio; Trávníček, P.; Prouza, M.; Gaug, M.; Keilhauer, B.
    L'Aquila (Italy) lidar station is part of the EARLINET (European Aerosol Research Lidar Network) since its beginning in the 2000. In the EARLINET community great efforts are devoted to the quality-assurance of the aerosol optical properties inserted in the database. To this end, each lidar station performed intercomparisons with reference instruments, a series of internal hardware checks in order to assess the quality of their instruments and exercises to test the algorithms used to retrieve the aerosol optical parameters. In this paper we give an overview of our experience within EARLINET qualityassurance (QA) program, which was adopted for the Raman lidar (RL) operated in the AUGER Observatory. This program could be systematically adopted for the lidar systems needed for the current and upcoming UHECR experiments, like CTA (Cherenkov Telescope Array).
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    Measurement of the linear depolarization ratio of aged dust at three wavelengths (355, 532 and 1064 nm) simultaneously over Barbados
    (Les Ulis : EDP Sciences, 2016) Haarig, Moritz; Althausen, Dietrich; Ansmann, Albert; Klepel, André; Baars, Holger; Engelmann, Ronny; Groß, Silke; Freudenthaler, Volker
    A ground-based polarization Raman lidar is presented, that is able to measure the depolarization ratio at three wavelengths (355, 532 and 1064 nm) simultaneously. This new feature is implemented for the first time in a Raman lidar. It provides a full dataset of 3 backscatter coefficients, two extinction coefficients and 3 depolarization ratios (3+2+3 lidar system). To ensure the data quality, it has been compared to the well characterized two-wavelength polarization lidar POLIS. Measurements of long-range transported dust have been performed in the framework of the Saharan Aerosol Long-Range Transport and Aerosol-Cloud-Interaction Experiment (SALTRACE) in the Caribbean.
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    Accuracy of linear depolarisation ratios in clean air ranges measured with POLIS-6 at 355 and 532 NM
    (Les Ulis : EDP Sciences, 2016) Freudenthaler, Volker; Seefeldner, Meinhard; Groß, Silke; Wandinger, Ulla
    Linear depolarization ratios in clean air ranges were measured with POLIS-6 at 355 and 532 nm. The mean deviation from the theoretical values, including the rotational Raman lines within the filter bandwidths, amounts to 0.0005 at 355 nm and to 0.0012 at 532 nm. The mean uncertainty of the measured linear depolarization ratio of clean air is about 0.0005 at 355 nm and about 0.0006 at 532 nm.