43 research outputs found
Monitoring Water Turbidity Using Remote Sensing Techniques
In the present work, the use of optical cameras for turbidity measurements is tested on the Bode River in Germany, which is one of the best-instrumented catchments in Central Germany with a long-term time series on water quantity and quality. Four trap cameras have been installed on monitored cross-sections with the aim to explore the potential of RGB indices for the description of water turbidity. A description of the experimental setup and some preliminary results are introduced
Methods to Retrieve the Cloud-Top Height in the Frame of the JEM-EUSO Mission
The Japanese Experiment Module-Extreme Universe
Space Observatory (JEM-EUSO) telescope will measure
ultrahigh-energy cosmic ray properties by detecting the UV
fluorescence light generated in the interaction between cosmic
rays and the atmosphere. Therefore, information on the state of
clouds in the atmosphere is crucial for a proper interpretation of
the data. For a real-time observation of the clouds in the telescope
field of view, the JEM-EUSO will use an atmospheric monitoring
system composed of a light detection and ranging and an infrared
(IR) camera. In this paper, the focus is on the IR camera data.
To retrieve the cloud-top height (CTH) from IR images, three
different methods are considered here. The first one is based
on bispectral stereo vision algorithms and requires two different
views of the same scene in different spectral bands. For the second
one, brightness temperatures provided by the IR camera are converted
to effective cloud-top temperatures, from which the CTH is
estimated using the vertical temperature profiles. A third method
that uses the primary numerical weather prediction model output
parameters, such as the cloud fraction, has also been considered
to retrieve the CTH. This paper presents a first analysis, in which
the heights retrieved by these three methodologies are compared
with the heights given by the Moderate Resolution Imaging
Spectroradiometer sensor installed on the polar satellite Terra.
Since all these methods are suitable for the JEM-EUSO mission,
they could be used in the future in a complementary way to
improve the accuracy of the CTH retrieval