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First Result of B istatic F orward- l ooking SAR with Stationary Transmitter. Junjie Wu , Jianyu Yang, et.al. Univ. of Electro. Sci. & Tech. of China. Contents. Introduction System Setup Experimental result of stationary transmitter BFSAR Current work. May, 12 th , Sichuan. - PowerPoint PPT Presentation
Citation preview
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Univ. of Electro. Sci. & Tech. of China
Junjie Wu, Jianyu Yang, et.al.
First Result of Bistatic Forward-looking SAR
with Stationary Transmitter
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ContentsContents
1.Introduction
2.System Setup
3.Experimental result of stationary transmitter BFSAR
4.Current work
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May, 12th, SichuanMay, 12th, Sichuan
Mar, 11th, Tohuku
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Side-looking
Squint-looking
Squint-looking
Backward-looking
Forward-looking1.Introduction
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• Obstruction warning
• Scene matching guidance
• Self-landing
• Self-navigation
• Materials and/or troop dropping
1.Introduction
Forward-looking radar imaging :
Forward Squint SAR
Forward Squint SAR
Boresight SAR
Boresight SAR
Forward looking radar
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Why can not SAR work in forward-looking mode?
1.Introduction
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SAR imaging conditions :
• there is enough separation angle----2D resolution• sole intersection----No ambiguity
Iso-range and Iso-Doppler lines —
Monostatic SAR Iso-range and Iso-Doppler lines
Monostatic SAR imaging area :• Iso-range and Iso-Doppler lines are orthogonal
• Sole intersection
1.Introduction
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Monostatic SAR Iso-range and Iso-Doppler lines
Monostatic SAR forward-looking area :• Iso-range and Iso-Doppler lines are parallel
• Double intersections
ar
Monostatic SAR : can not image the forward-looking area
1.Introduction
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What can we do?
Separate the transmitter and receiver
Bistatic
1.Introduction
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Bistatic SAR :can image the forward-looking area of the receive station
Bistatic SAR Iso-range and Iso-Doppler lines
Bistatic SAR forward-looking area :• Iso-range and Iso-Doppler lines are not parallel
• Sole intersections
1.Introduction
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• Transmitter Side-looking or Squint
• Receiver forward-looking
BFSAR with two moving platforms
• Spaceborne transmitter——Airborne receiver
• Airborne transmitter——Airborne receiver
• Reconnaissance
• Self-navigation
• Air-drop
TransmitterSide-looking
ReceiverForward-looking
1.Introduction
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FGAN-Germany
Spaceborne transmitter side-looking
Airborne receiver backward-looking
• Spaceborne/airborne bistatic backward-looking experiment (2009.12)
BFSAR1.Introduction
Resolution : 1-3m Area: 3×5km
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Forward-looking Receiver
Stationary transmitter
1.Introduction Stationary Transmitter (ST) BFSAR
• Transmitter----high tower, mountain, geostationary satellite, stratosphere low speed airship…• Receiver----airborne
• Reconnaissance
• Self-navigation
• Air-drop
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(a) monostatic FSAR (b) ST-BFSAR
1.Introduction Imaging principle of ST-BFSAR
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2.System Setup
Vector Signal Generator
Agilent 8267D
Stationary Transmitter
Wideband signal receiver
target
Vehicle-borne Moving Receiver
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2.System Setup
Bandwidth: 80MHz
PRF: 500Hz
Pulse Width: 20us
Receiver velocity: 7m/s
Carrier Frequency: 9.6GHz
System parameters
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2.System Setup
Downward-looking angle is too small
Target
Upward forward-looking Downward forward-lookingEquivalent
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2.System Setup
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0 1000 2000 3000 4000 5000 6000 7000 8000 90000
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方 位 向 采 样 点0 1000 2000 3000 4000 5000 6000 7000 8000 9000
0
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9x 10
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方 位 向 频 率 , 采 样 点
3. Experimental results
Slow time domain Doppler domain
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Imaging result of ST-BFSAR
3. Experimental results
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4.Current Work
A
O
B
CA
O
B
A
O C
B
A
O
2D spatial variance
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4.Current Work
Keystone-based azimuth nonlinear Chirp Scaling imaging algorithm
Keystone transform:
Correct the linear range walk of all targets
----remove the variance of range migration
NLCS:
Equalize the FM rates of all targets
---- remove the variance of azimuth FM rate
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Thank you