The Barcelona Raman LIDAR for the CTAO-North

^(a) Departament de Física, Universitat Autonoma de Barcelona and CERES-IEEC E-08193 Bellaterra, Spain
^(b) Institut de Física d'Altes Energies (IFAE), Barcelona Institute of Science and Technology (BIST) E-08193 Bellaterra, Spain
^(c) Cherenkov Telescope Array Observatory gGmbH (CTAO gGmbH) Sauaupfercheckweg 1, 69117 Heidelberg, Germany
^(d) Department of Physics and Astronomy, University of Padova I-35131 Padova, Italy
^(e) Istituto Nazionale di Fisica Nucleare (INFN), sez. di Padova I-35131 Padova, Italy
^(f) Center for Astrophysics and Cosmology, University of Nova Gorica Vipavska 13, 5000 Nova Gorica, Slovenia This email address is being protected from spambots. You need JavaScript enabled to view it.

Published online: 9 April 2026

Abstract

The Barcelona Raman LIDAR (BRL) project is developing a LIDAR for online aerosol characterization of the northern site of the Cherenkov Telescope Array Observatory (CTAO-N). Such telescopes observe Cherenkov light emitted throughout the lower stratosphere and the troposphere, the aerosol and cloud profiles of which must be continuously monitored. Requirements include the ability to take aerosol extinction profiles to distances of more than 30 km and time scales of less than a minute after pointing to any target in the sky down to 25° altitude. The BRL consists of a 1.8 m parabolic mirror and a pulsed Nd-YAG laser. A liquid light guide collects the light at the focal plane and transports it to an in-house built polychromator unit. A prototype of the device was brought to the site and tested, the experience of which has resulted in a few improvements to the system.