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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.
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First Result of Bistatic Forward-looking 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, 12th, Sichuan May, 12th, Sichuan Mar, 11th, Tohuku
1.Introduction Forward-looking Squint-looking Side-looking Squint-looking Backward-looking
1.Introduction Forward-looking radar imaging: • Obstruction warning • Scene matching guidance • Self-landing • Self-navigation • Materials and/or troop dropping Forward looking radar Forward Squint SAR Forward Squint SAR Boresight SAR Boresight SAR
1.Introduction Why can not SAR work in forward-looking mode?
Monostatic SAR imaging area: • Iso-range and Iso-Doppler lines are orthogonal • Sole intersection Monostatic SAR Iso-range and Iso-Doppler lines 1.Introduction SAR imaging conditions: Iso-range and Iso-Doppler lines — • there is enough separation angle----2D resolution • sole intersection----No ambiguity
1.Introduction • Monostatic SAR forward-looking area: • Iso-range and Iso-Doppler lines are parallel • Double intersections Monostatic SAR Iso-range and Iso-Doppler lines Monostatic SAR:can not image the forward-looking area
1.Introduction What can we do? Separate the transmitter and receiver Bistatic
1.Introduction • Bistatic SAR forward-looking area: • Iso-range and Iso-Doppler lines arenot parallel • Sole intersections Bistatic SAR Iso-range and Iso-Doppler lines Bistatic SAR: canimage the forward-looking area of the receive station
1.Introduction BFSAR with two moving platforms • Transmitter Side-looking or Squint • Receiver forward-looking Transmitter Side-looking • Spaceborne transmitter——Airborne receiver • Airborne transmitter——Airborne receiver Receiver Forward-looking • Reconnaissance • Self-navigation • Air-drop
1.Introduction BFSAR FGAN-Germany • Spaceborne/airborne bistatic backward-looking experiment(2009.12) Spaceborne transmitter side-looking Resolution:1-3m Area:3×5km Airborne receiver backward-looking
1.Introduction Stationary Transmitter (ST) BFSAR Stationary transmitter • Transmitter----high tower, mountain, geostationary satellite, stratosphere low speed airship… • Receiver----airborne Forward-looking Receiver • Reconnaissance • Self-navigation • Air-drop
1.Introduction Imaging principle of ST-BFSAR (a) monostatic FSAR (b) ST-BFSAR
2.System Setup Stationary Transmitter Vector Signal Generator Agilent 8267D target Vehicle-borne Moving Receiver Wideband signal receiver
2.System Setup System parameters Carrier Frequency: 9.6GHz Bandwidth: 80MHz PRF: 500Hz Pulse Width: 20us Receiver velocity: 7m/s
2.System Setup Downward-looking angle is too small Target Upward forward-looking Downward forward-looking Equivalent
3. Experimental results Slow time domain Doppler domain
3. Experimental results Imaging result of ST-BFSAR
4.Current Work A A A A C O O O C O B B B 2D spatial variance
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