This paper presents a low-cost system for the measurement of atmospheric visibility. The
measurement setup is composed by a consumer digital camera which is controlled by a
computer. The camera acquires photos of the landscape that include natural dark objects.
Then the computer calculates the atmospheric visibility based on the apparent contrast,
against the background, of these dark objects through the Lambert–Beer law. Two different
approaches are proposed so that the system is able to measure the atmospheric visibility
both under normal and low visibility conditions. The use of the three color channels of
the camera allows the measurement of the extinction coefficient at different wavelengths
along with the Angström exponent which is an important parameter in the classification of
atmosphere aerosols.
Measurements performed with the developed system are presented and include the
atmospheric visibility, the extinction coefficient and the Angström exponent. The results
presented correspond to the measurements performed along a week that included a desert
dust event. This event dramatically reduced the atmospheric visibility due to the desert
dust particles. Angström exponent measurements were performed with another instrument
for comparison. Finally, an uncertainty analysis of the measured atmospheric visibility
is presented.