Foliage/Ground Penetration Radar
Ground Penetrating Radar
The Radar Physics Group has a growing program in performing ground and foliage penetration,
primarily from airborne platforms. Currently, the platform being used is a UH-1 Huey helicopter,
configured with a palletized MkV radar.
The initial configuration for this system used
horizontal (H) and vertical (V) polarized log dipole antennas and step-chirped the transmit
signal over the frequency range from 150 - 450 MHz. Some steps in the chirp were suppressed to
make the radar conform to FCC frequency clearance requirements. Data were collected for SAR
imaging in both HH and VV mode.
In this configuration, data at 1 m resolution were acquired over 10 square miles of terrain in
Oklahoma. Data from this initial configuration were processed using both tomagraphic and range
migration algorithms.
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After completion of this first project, a number of adjustments were made to the system
configuration. The most important of these changes was replacing the log periodic antennas with
an array of crossed dipoles to improve the system gain and allow efficient collection of
crossed-polarization data. The low frequency system was supplemented with an X-band array;
the data from which is used to help low-frequency data interpretation and to provide ground
truth for the radar data. Due to the large size of the crossed dipole antennas
and their mounting structure, mounting them on a skid could have a negative influence on the
helicopter flight characteristics. Instead mounting stucture is designed to be carried beneath
the skids and can be jettisoned in case of an emergency.
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