Imaging of object in cluttered environments (sponsored
by ONR, NSF)
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Summary
This
project investigates an adaptive imaging approach, namely that of a
synthetic wideband, stepped CW transmitter and a multi-channel, adaptive
array for receiving backscattered energy from short range objects in a
full +/- 90 degree field of view. The method is a hybrid one, using
conventional Fourier processing for range and is adaptive in angle. The
results show how background clutter affects the angular resolution of
the array due to the increase in rank of the signal plus clutter
covariance matrix, whereas at the same time the rank of this matrix is
reduced for closely spaced scatterers due to signal coherence. In
addition to investigating some known angular enhancement methods, we
study a method to enhance angular resolution in the presence of clutter
by a projection, which seeks to reduce the received signal to a lower
rank approximation, without using eigen decomposition, thus having an
implementation advantage. This method allows more control over the
angular resolution and the background clutter level.
Testing
the 12-channel imaging array system in the anechoic chamber.
Image of
one large dihedral and 3 cylinders using adaptive beam forming
techniques.
Related publications
- A. Ishimaru, S.
Jaruwatanadilok, Y. Kuga, and J Rockway, "Imaging
of objects in random media and near rough surfaces," EM
Scattering Modeling and Information Retrieval in Remote Sensing,
Fudan University, Shanghai, China, August 25-27, 2004.
- A. Ishimaru, S. Jaruwatanadilok,
and Y. Kuga, "Multiple
Scattering Effects on Radar Cross Section (RCS) of Objects in Random
Media Including Backscattering Enhancement and Shower Curtain
Effects," URSI - APS, Monterey, CA, June 20-26, 2004.
- M. Curry and Y. Kuga, "Resolution
improvement techniques for microwave imaging in random media using
small wideband adaptive arrays," SPIE: Remote Senging and
Space Technology, Seattle, WA, August 7-11, 2002.
- M. Curry and Y. Kuga, "Experimental
results for adaptive radar imaging in a wide angular sector,"
International Radar Conference, Atlanta, Georgia, May 1-3, 2001.
2nd place for Paper Competition
- M. Curry, M. Ciccotosto, B.
Koala, and Y. Kuga, "Indoor
angle of arrival using wide-band frequency diversity with
experimental results and EM propagation modeling," IEEE APS
on Antennas and Propagation for Wireless Communications,
Waltham, MA, November 6-8, 2000.
- M. Curry and Y. Kuga, "Radar
imaging using a wide band adaptive arry," International Radar
Conference, Alexandria, VA, May 7-12, 2000.
- A. Ishimaru, and Y. Kuga, "Array
coherence tomography (ACT) imaging in clutter environment,"
IEEE Topical Conference on Wireless Communication Tecnology,
Honolulu, Hawaii, October 15-17, 2003.
Sponsored by ONR, NSF
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