Time-reversal and MUSIC

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Time-reversal and MUSIC
Anthony J. Devaney Department of Electrical and
Computer Engineering Northeastern
University Boston, MA 02115 email
tonydev2_at_aol.com
Review of time-reversal Discussion of Vector
Spaces Incorporation of MUSIC Computer
Simulations
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System Configuration
Antenna element
Point Scatterers
Assumes Born Approximation
Antenna Array
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Incident Wavefield
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Scattered Wavefield--Born
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Receive Voltage
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Time-Reversal Matrix
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Array Point Spread Function
Backpropagated field from scatterer located at
Xm evaluated at field location r
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Well-resolved Targets
Backpropagated field from scatterer located at
Xm vanishes at all other scatterer locations
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Vector Spaces for W.R.T.
Noise Subspace
Signal Subspace
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Focusing with Time-reversal
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Focused versus time-reversed fields
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Non-well Resolved Targets
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MUSIC
Pseudo-Spectrum
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Computer Simulation

• Future Directions
• Extended Objects
• Random Media
• Sparse Arrays

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Pseudo-spectrums
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Contour plots of Pseudo-spectrums