Electrical and Computer Engineering -

1
MICROWAVE REMOTE SENSING OF THE
ATMOSPHERE Sandra L. Cruz-Pol, Ph D Associate
Professor, ECE - UPRM
Stratus Clouds (non-precipitating clouds)
Better understanding of dynamics of heat transfer
in atmosphere
The work presented here includes several projects
covering the area of remote sensing of the
atmosphere, including rain and clouds, using
microwave sensors such as radar and radiometer.
Several physical parameters important to weather
prediction and climate modeling such as mean
drop size diameter, and rain rate distribution
can be retrieve from the information provided by
these sensors.
Stratus Clouds lower in the troposphere, high
albedo horizontal extent, more impact in
radiation budget.
Benefit Climate prediction models such as the
General Circulation Model (GCM)
Doppler Radar for Precipitation
UMass Cloud Profiling Radar System (CPRS)
captures the microphysical profile of a stratus
cloud.
Microwave remote sensing has the advantage over
optical remote sensing in that the information
do not depend on the illumination by the Sun,
therefore radars can "see" during the night as
well as during the day. Radars can also penetrate
clouds and provide information about the
microphysical properties of clouds and rain.
In this work we develop algorithms and calibrate
models to better retrieve the physical and
radiative characteristics of the atmosphere,
including water vapor contain, liquid water, and
raindrop distribution. Below are the retrieve
images of two stratus clouds.
DOE-ARM SGP-CART at Oklahoma controlled from UPRM
Atmospheric Attenuation for Scan Radars
UPRM student next to UMass W-band radar in OK.
Radar signals suffer atmospheric attenuation due
to water vapor and oxygen gases as they travel
through the atmosphere. It was demonstrated that
the higher attenuation exhibited at angles away
from zenith for the 95 GHz is due to the
atmospheric attenuation as shown by the
simulation since at these angles the signal
travels longer path through the lower layer of
the atmosphere. Simulation was compared to
actual data collected in Australia during
convection season, 1995.(below)
Data from the UMass Cloud Profiling Radar System
(CPRS) operating at 33GHz and 95GHz is analyzed
and presented here as well as preliminary data
from the NOAA wind profiler, operating at 2.8GHz.
This work is performed in collaboration with
UMass, and is sponsored by grants from NASA and
NSF.
Ocean Emissivity and Atmospheric Absorption
Model Near 22GHz.
Minimum detectable dBZ for 33GHz
Minimum detectable dBZ for 95GHz
Above, NOAA S- band and UMass W-band radar
response to precipitation events. Drop size
distribution and total liquid water are some of
the retrieved parameters.
CPRS Data of dBZ (33GHz).
CPRS Data of dBZ (95GHz).
Electrical and Computer Engineering - Center
for CLoud Microwave Measurements of Atmospheric
Events, UPRM
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