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Instruments

Lidar measurements


backscatter/depolarization lidar

The lidar was developed at the University of Rome to measure aerosol backscattering and depolarization profiles at 532 nm throughout the troposphere in daytime conditions. The system was upgraded in 2002 to expand the sounding interval towards lower altitudes (the range is now 0.1-10 km). In its present configuration it is composed of a Nd:YAG laser emitting linearly polarized pulses at 532 nm at a repetition rate of 10 Hz, two 100 mm diameter Cassegrain telescopes that collect radiation with polarization parallel and orthogonal to that of the laser beam, and a 50 mm diameter refractive telescope that collects signals from the lowest atmospheric layers. The signals are detected by photomultipliers and fast analog to digital converters.

The lidar is operated by the University of Rome in selected periods, and has been used to study the properties of Saharan dust over Lampedusa.

A water vapor daylight Raman lidar is being developed jointly by ENEA and University of Rome. The installation of the system is expected to occur in year 2004.


evolution of the lidar backscatter ratio at 532 nm versus altitude and time on May 28 (top graph) and June 3, 1999.
On June 3 desert dust was transported to Lampedusa from Sahara.