An automatic, low-cost telemetric lidar for the continuous monitoring of urban aerosols in the surface Layer
Authors: Del Guasta M., Castagnoli F., Baldi M., Venturi V.
Autors Affiliation: Istituto Fisica Applicata Nello Carrara, Consiglio Nazionale delle Ricerche, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Firenze), Italy
Abstract: An old-fashioned technology such as the \”searchlight profiler\”, which was used in the 1960s for the early profiling of atmospheric backscatter, recently modified for its use with lasers and CCD cams1, has been revisited in the telemetric-LIDAR described here. The instrument is intended for the low-cost monitoring of urban aerosols, with a limited useful range of 100-200 meters. A modulated CW laser beam is used to probe the atmosphere, and a refractive telescope is used to collect the backscattered light on a photodiode array. Like in a telemetric system, the distance between the laser beam and the telescope axis determines the range resolution and the distance of the measurement volume corresponding to each pixel of the array. The system was used in conjunction with in-situ PM10 instruments for several months of continuous operation in Prato and Florence (Italy). The comparison between LIDAR-derived and conventional PM10 measurements is shown.
KeyWords: Atmospheric aerosols; Backscattering; Charge coupled devices; Laser beams; Lasers; Light scattering; Monitoring; Optical instruments; Optical telescopes; Position measurement; Refraction; Remote sensing; Space probes; Telescopes, Backscattered lights; Continuous monitoring; Continuous operations; Cost monitoring; Cw laser beams; In-situ; LIDAR; Measurement volumes; Photodiode arrays; PM10; Range resolutions; Surface layers; Telemetric systems; Urban aerosols, Optical radar