Monitoring of the particles above the unpaved road by lidar technique

Basic concepts of laser-based technique LIDAR (LIght Detection and Ranging) are discussed in
this article as well as advantages and disadvantages. Presented are measurements of relative
particulate concentrations above an unpaved road which were performed in a rural area near the
Iowa City, Iowa, USA. The LIDAR system used in these measurements is a small, scanning LIDAR
that uses elastic backscattering to obtain information on the amount of atmospheric aerosols. In
the elastic LIDAR, light scattered back towards the LIDAR system from molecules and particles in
the atmosphere is collected by a telescope and is detected with a photodiode. A Big Sky Laser
model CFR-200 Nd:YAG laser operating at 1.064 microns is used to generate the LIDAR's
outgoing signal. The laser is attached directly to the top of a 26 cm, f/10 Cassegrian telescope. A
series of pulses are summed to make a single scan. A series of scans is used to build up a twodimensional
map of relative atmospheric aerosol concentrations. With a maximum range of about
6-8 km, a range resolution of 2.5 m, and a time resolution of 30 s, the LIDAR is capable of very
detailed mapping of aerosols.