Two-Antenna SAR With Waveform Diversity for Ground Moving Target Indication

Along-track interferometry (ATI) and displaced phase center antenna (DPCA) are two representative synthetic aperture radar (SAR) ground moving target indication (GMTI) techniques. However, the former is a clutter-limited detector, whereas the latter is a noise-limited detector. In this letter, we propose a two-antenna SAR with waveform diversity for GMTI. The two antennas placed in the azimuth dimension simultaneously transmit two orthogonal waveforms, namely, the up- and down-chirp waveforms. In doing so, four independent transmit-receive channels are obtained for the receiver, and thus, an efficient GMTI is developed by cooperatively utilizing the ATI GMTI and DPCA GMTI processing techniques. This method first uses the DPCA technique to cancel clutter and then the ATI technique to suppress noise. Next, the fractional Fourier transform is employed to estimate the Doppler parameters and corresponding reference filters are designed to focus the moving targets. The proposed approach cooperatively utilizes the advantages of ATI and DPCA GMTI techniques and overcomes their disadvantages. It does not prerequire knowledge of the target's across-track velocity. The effectiveness is verified by simulation results.

[1]  Vito Pascazio,et al.  Estimation of Radial Velocity of Moving Targets by Along-Track Interferometric SAR Systems , 2008, IEEE Geoscience and Remote Sensing Letters.

[2]  B. Dawidowicz,et al.  Suppression of the ground clutter in airborne PCL radar using DPCA technique , 2009, 2009 European Radar Conference (EuRAD).

[3]  Jian Li,et al.  Ground Moving Target Indication via Multichannel Airborne SAR , 2011, IEEE Transactions on Geoscience and Remote Sensing.

[4]  Wen-Qin Wang,et al.  MIMO SAR imaging: Potential and challenges , 2013, IEEE Aerospace and Electronic Systems Magazine.

[5]  B. D. Steinberg,et al.  Reduction of sidelobe and speckle artifacts in microwave imaging: the CLEAN technique , 1988 .

[6]  A. Monti Guarnieri,et al.  Maximum likelihood multi-baseline Sar interferometry , 2006 .

[7]  Yue Wang,et al.  Iterative Successive Interference Cancellation for Quasi-Synchronous Block Spread CDMA Based on the Orders of the Times of Arrival , 2011, EURASIP J. Adv. Signal Process..

[8]  Shen Chiu,et al.  A comparison of displaced phase centre antenna and along-track interferometry techniques for RADARSAT-2 ground moving target indication , 2005 .

[9]  Christoph H. Gierull,et al.  Ground Moving Target Indication With Tandem Satellite Constellations , 2008, IEEE Geoscience and Remote Sensing Letters.

[10]  A. Beaudoin,et al.  An airborne synthetic aperture radar (SAR) experiment to support RADARSAT-2 ground moving target indication (GMTI) , 2002 .

[11]  Marina V. Dragosevic,et al.  Moving Target Indication via RADARSAT-2 Multichannel Synthetic Aperture Radar Processing , 2010, EURASIP J. Adv. Signal Process..

[12]  Shen Chiu,et al.  Application of Fractional Fourier Transform to Moving Target Indication via Along-Track Interferometry , 2005, EURASIP J. Adv. Signal Process..

[13]  Zheng Bao,et al.  A Knowledge-Based Target Relocation Method for Wide-Area GMTI Mode , 2014, IEEE Geoscience and Remote Sensing Letters.

[14]  C. H. Gierull.  Ground moving target parameter estimation for two-channel SAR , 2006 .

[15]  Jian Yang,et al.  Imaging and Parameter Estimation of Fast-Moving Targets With Single-Antenna SAR , 2014, IEEE Geoscience and Remote Sensing Letters.

[16]  Xiaotao Huang,et al.  New Approach for SAR Imaging of Ground Moving Targets Based on a Keystone Transform , 2011, IEEE Geoscience and Remote Sensing Letters.

[17]  Fred Daum,et al.  MIMO radar: Snake oil or good idea? , 2008, 2009 International Waveform Diversity and Design Conference.

[18]  Wen-Qin Wang,et al.  Moving Target Indication via Three-Antenna SAR with Simplified Fractional Fourier Transform , 2011, EURASIP J. Adv. Signal Process..

[19]  Wei Xu,et al.  Multichannel synthetic aperture radar systems with a planar antenna for future spaceborne microwave remote sensing , 2012, IEEE Aerospace and Electronic Systems Magazine.

[20]  Luís B. Almeida,et al.  The fractional Fourier transform and time-frequency representations , 1994, IEEE Trans. Signal Process..

[21]  Junfeng Wang,et al.  Ground Moving Target Indication in SAR Images by Symmetric Defocusing , 2013, IEEE Geoscience and Remote Sensing Letters.

[22]  Gozde Bozdagi Akar,et al.  Digital computation of the fractional Fourier transform , 1996, IEEE Trans. Signal Process..