Geoscience Reference
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(4) Salt and pollutant concentration of water areas (off-shore zones, lakes):
•
operating range is 1
300 ppt;
-
•
maximum absolute error is 1
5 ppt;
-
•
relative error is 0.5 ppt.
Large-scale investigations on the creation of microwave research carrying
platforms were realized by Microwave Remote Sensing Division (MRSD) in 2002
through 2005 within the NASA Center for Hydrology, Soil Climatology and
Remote Sensing (HSCaRS) at Alabama Agricultural and Mechanical University
(AAMU). This Division was capable of performing microwave radiometric data
interpretation and conducting studies in
field conditions, from mobile platform and
unmanned helicopter.
The antennas, radiometers, data collection system and an embedded Global
Positioning System (GPS) receiver were mounted on the manned Rover type mobile
platform and unmanned helicopter platformMicrowave Autonomous Copter System
(MACS) for measuring the soil-plant system radiation. All radiometers were mounted
on a folding mounting panel to observe horizontally polarized radiation when folding
the panel is situated between the nadir through zenith looking angle. The GPS
information was used to register the microwave reading to a common coordinate
system of the study area. The data capture rate was set to 1 measurement per second in
each of the radiometric channels and GPS readings.
The manned
ed Gator utility vehicle. This
two-seater vehicle has a 286 cc, air-cooled, 4-cycle gasoline engine. Its towing
capacity is 500 lb (226 kg) with a top speed of 20 mph (32 km/h). The instrument
platform (or mounting frame) for the radiometers and other instruments was
assembled at AAMU research station. The aluminum folding panel of 1.5 m
“
Rover
”
type mobile platform is a modi
1.5 m
connecting all system components was designed so that the incidence angle from 0
×
°
(nadir) to 180
(sky) could be easily obtainable (Figs.
2.8
and
2.9
and Table
2.11
).
The radiometers were mounted with the antennas viewing off to the right hand side of
the platform at an incidence angle of 10
°
°
. The radiometer
“
Rover
”
shuttled back and
forth in a north-south direction at a speed of 2
5 mph. using the developed remote
sensing system data obtained from a height of 2 m provided the spatial resolution of
1.4 m of land area.
The unmanned helicopter platform MACS was equipped with a 6 cm radiometer
(incidence angle 5
-
) mounted on the nose of the AutoCopter
TM
onto a stabilized
gimbal with pan/tilt interface which attenuates vibrations (Fig.
2.10
, and Table
2.12
).
The MACS is a modi
°
ed AutoCopter
TM
, a small unmanned helicopter platform that
can
flight path) or semi-autonomously (with
an operator directing the maneuvers). This is a product of Neural-Robotics, Inc. (NRI)
of Huntsville, AL.
The unmanned helicopter advantage is its patented
fl
fly autonomously (
fl
y a pre-programmed
fl
flight control system con-
sisting of multiple neural network modules working together. The result is an
autonomous helicopter that adapts to changing conditions and provides an extre-
mely stable platform for hundreds of applications. The AutoCopter
TM
is 2.18 m in
length (from tip of tail rotor to tip of main rotor) and weighs approximately 13.6 kg.
fl
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