FOliage PENetration Synthetic Aperture Radar (FOPEN SAR) is used in low Signal-to-Clutter Ratio (SCR) conditions to detect targets hidden in forests, which introduces difficulties in target detection. In this study, an enhanced imaging method based on the scattering aspect variability of the target is proposed, which improves the SCR of the formed images of hidden targets while maintaining high spatial resolution. In the case of a vehicle target, the dihedral is formed by its main side and the ground. The echo is strongest when the incident electromagnetic wave is along the normal direction of the dihedral. A high-resolution image corresponding to this aspect angle is formed by the proposed enhanced imaging method to increase the SCR of the target and improve the detection performance. Airborne FOPEN SAR data were used to validate the efficiency of the proposed method.
Davis M E. Foliage Penetration Radar: Detection and Characterization of Objects under Trees[M]. SciTech Publishing, Inc, 2011: 60-92.
[2]
Novak L M, Halversen S D, Owirka G J, et al.. Effects of polarization and resolution on SAR ATR[J]. IEEE Transactions on Aerospace and Electronic Systems, 1997, 33(1): 102-116.
[3]
吴一戎. 多维度合成孔径雷达成像概念[J]. 雷达学报, 2013, 2(2): 135-142.Wu Yi-rong. Concept on multidimensional space joint-observation SAR[J]. Journal of Radars, 2013, 2(2): 135-142.
[4]
Kaplan L M, McClellan J H, and Seung-Mok Oh. Prescreening during image formation for ultrawideband radar[J]. IEEE Transactions on Aerospace and Electronic Systems, 2002, 38(1): 74-88.
[5]
Carin L, Ybarra G, Bharadwaj P, et al.. Physics-based classification of targets in SAR imagery using subaperture sequences[C]. IEEE International Conference on Acoustics, Speech and Signal Processing, Phoenix, AZ, USA, 1999: 3341-3344.
[6]
Runkle P, Nguyen L H, McClellan J H, et al.. Multi-aspect target detection for SAR imagery using hidden Markov models[J]. IEEE Transactions on Geoscience and Remote Sensing, 2001, 39(1): 46-55.
[7]
Soumekh M, Gunther G, Linderman M, et al.. Digitally-spotlighted subaperture SAR image formation using high performance computing[C]. Proceedings of SPIE, 2000, 4053: 260-271.
[8]
Wong D and Carin L. Analysis and processing of ultra wide-band SAR imagery for buried landmine detection[J]. IEEE Transactions on Antennas and Propagation, 1998, 46(11): 1747-1748.
[9]
杨威, 陈杰, 李春升. 面向目标特性精细提取的SAR数据融合成像处理方法[J]. 雷达学报, 2015, 4(1): 29-37.Yang Wei, Chen Jie, and Li Chun-sheng. SAR data fusion imaging method oriented to target feature extraction[J]. Journal of Radars, 2015, 4(1): 29-37.
[10]
Chaney R D, Willsky A S, and Novak L M. Coherent aspect-dependent SAR image formation[C]. Proceedings of SPIE, 1994, 2230: 256-274.
[11]
Jackson J A, Rigling B D, and Moses R L. Canonical scattering feature models for 3D and bistatic SAR[J]. IEEE Transactions on Aerospace and Electronic Systems, 2010, 46(2): 525-541.
[12]
Martin W and Flandrin P. Wigner-Ville spectral analysis of nonstationary processes[J]. IEEE Transactions on Acoustics, Speech, and Signal Processing, 1985, 33(6): 1461-1470.
[13]
Choi H-I and Williams W J. Improved time-frequency representation of multicomponent signals using exponential kernels[J]. IEEE Transactions on Acoustics, Speech, and Signal Processing, 1989, 37(6): 862-871.
[14]
洪文. 圆迹SAR成像技术研究进展[J]. 雷达学报, 2012, 1(2): 124-135.Hong Wen. Progress in circular SAR imaging technique[J]. Journal of Radars, 2012, 1(2): 124-135.
2015, Vol. 4 
