An innovative mobile lidar device, developed to monitor volcanic plumes during explosive eruptions at Mt. Etna (Italy) and to analyse the optical properties of volcanic particles, was upgraded in October 2023 with the aim of improving volcanic plume retrievals. The new configuration of the lidar allows it to obtain new data on both the optical and the microphysical properties of the atmospheric aerosol. In fact, after the upgrade, the lidar is able to measure three backscattering coefficients, two extinction coefficients and two depolarisation ratios in a configuration defined as “state-of-the-art lidar”, where properties such as particle size distribution and the refractive index can be derived. During the lidar implementation, we were able to test the system’s performance through specific calibration measurements. A comparison in an aerosol-free region (7.2–12 km) between lidar signals at 1064 nm, 532 nm and 355 nm and the corresponding pure molecular profiles showed a relative difference of <1% between them for all the wavelengths, highlighting the good dynamic of the signals. The overlap correction allowed us to reduce the underestimation of the backscattering coefficient from 50% to 10% below 450 m and 750 m at both 355 and 532 nm, respectively. The correct alignment between the laser beam and the receiver optical chain was tested using the signal received from the different quadrants of the telescope, and the relative differences between the four directions were comparable to zero, within the margin of error. Finally, the first measurement results are shown and compared with results obtained by other instruments, with the aim of proving the ability of the upgraded system to more precisely characterise aerosol optical and microphysical properties.

An innovative mobile Lidar device, developed to monitor volcanic plumes during explosive eruptions at Mt. Etna (Italy) and analyze the optical properties of volcanic particles was upgraded in October 2023 with the aim to improve volcanic plume retrievals. The new configuration of the lidar allows to obtain new data of both the optical and the microphysical properties of the atmospheric aerosol. In fact, after its upgrade, the lidar has the possibility to measure 3β, 2α and 2δ in a configuration defined as “state of the art lidar” where properties such as the particle size distribution and refractive index can be derived. During the lidar implementation we were able to to test the system performance through specific calibration measurements. In this work, the first measurement results are shown and compared with results obtained by other instruments aimed at proving the ability of the upgraded system to more precisely characterize the aerosol optical and microphysical properties.

We report on a recently designed and developed cutting-edge lidar system for aerosol remote sensing, complying with the demands for data quality and system characteristics established in ACTRIS (Aerosol, Clouds and Trace Gases Research Infrastructure). The first prototype of this lidar system is currently operative at the Naples ACTRIS National Facility (NF). It is the first compact and transportable two-wavelength elastic/Raman lidar system, equipped with scanning and polarization discrimination capabilities, specially designed for atmospheric investigations from a range of about 0.2 km up to 25 km, combining compactness, accuracy, autonomy in remote use, and ease of operation. The system uses an acquisition board specifically developed for transportable systems in a compact configuration that was tested at the CARS-CNR CIAO ACTRIS calibration center, demonstrating high performance in terms of the signal-to-noise ratio. ACTRIS calibration procedures for high-power aerosol lidars were carried out to assess the system performance according to the standard quality assurance protocols for ACTRIS NF operation. In this work, we report a description of the system, the calibration testing, and the results of the first measurements, demonstrating its ability to characterize aerosol optical properties in the troposphere and the lower stratosphere.