volume | PIER Journals

Abstract

Circular synthetic aperture radar (CSAR) is different from other usual SAR modes, e.g., Stripmap SAR or Spotlight SAR, which takes a circular path rather than a straight path. It can provide not only two-dimensional (2-D) high resolution images but also three-dimensional (3-D) information about the target. In this paper, 2-D CSAR imaging containing 3-D information about the target is discussed. Considering the limited bandwidth of radar system and the limited angular persistence of the reflector's scattering characteristic in a real scene, we combine the data extrapolation technique based on the autoregressive (AR) model with the non-coherent combination of the sub-aperture images based on the approximate Generalized Likelihood Ratio Test (GLRT) technique to get a 2-D CSAR image with resolution improved and with aspect-dependent reflectivity characteristics kept. The GTRI T-72 tank dataset is processed to test the algorithm.

1. Soumekh, M., Synthetic Aperture Radar Signal Processing with Matlab Algorithms, Ch. 7, Wiley, New York, 1999.

2. Soumekh, M., "Reconnaissance with slant plane circular SAR imaging," IEEE Trans. Image Process., Vol. 5, No. 8, 1252-1265, Aug. 1996.
doi:10.1109/83.506760 Google Scholar

3. Ishimaru, A., T. Chan, and Y. Kuga, "An imaging technique using confocal circular synthetic aperture radar," IEEE Trans. Geosci. Remote Sens., Vol. 36, No. 5, 1524-1530, Sep. 1998.
doi:10.1109/36.718856 Google Scholar

4. Dudgeon, D. E., R. T. Lacoss, C. H. Lazott, et al. "Use of persistant scatterers for model-based recognition," Proc. SPIE 2230, 356-368, Apr. 1994.
doi:10.1117/12.177192 Google Scholar

5. Trintinalia, L. C., R. Bhalla, and H. Ling, "Scattering center parameterization of wide-angle backscattered data using adaptive gaussian representation," IEEE Trans. Antennas and Propagation, Vol. 45, 1664-1668, Nov. 1997. Google Scholar

6. Odendaal, J. W., E. Barnard, and C. W. I Pistorius, "Two-dimensional superresolution radar imaging using the MUSIC algorithm," IEEE Trans. Antennas and Propagation, Vol. 42, No. 10, 1386-1391, 1994.
doi:10.1109/8.320744 Google Scholar

7. Roy, R. and T. Kailath, "ESPRIT-estimation of signal parameters via rotational invariance techniques," IEEE Transactions on Acoustics, Speech and Signal Processing, Vol. 37, No. 7, 984-995, 1989.
doi:10.1109/29.32276 Google Scholar

8. Gupta, I. J., M. J. Beals, and A. Moghaddar, "Data extrapolation for high resolution radar imaging," IEEE Trans. Antennas and Propagation, Vol. 42, No. 11, 1540-1545, 1994.
doi:10.1109/8.362783 Google Scholar

9. Kayran, A. H. and I. Erer, "Optimum asymmetric half-plane autoregressvie lattice parameter modeling of 2-D fields," IEEE Trans. Signal Processing, Vol. 52, No. 3, 807-819, 2004.
doi:10.1109/TSP.2003.822363 Google Scholar

10. Yu, L.-J. and Y.-H. Zhang, "One-dimensional spectrum extrapolation for circular SAR imaging," International Symposium on Antennas Propagation and EM Theory, Nov. 2010. Google Scholar

11. Stankwitz, H. C., R. J. Dallaire, and J. R. Fienup, "Non-linear apodization for sidelobe control in SAR imagery," IEEE Transactions on Aerospace and Electronic Systems, Vol. 31, No. 1, 267-279, 1995.
doi:10.1109/7.366309 Google Scholar

12. Zhai, W. and Y. Zhang, "Application of super-sva to stepped-chirp radar imaging with frequency band gaps between subchirps," Progress In Electromagnetics Research B, Vol. 30, 71-82, 2011. Google Scholar

13. Moses, R. L. and L. C. Potter, "Noncoherent 2D and 3D SAR reconstruction from wide-angle measurements," 13th Annual Adaptive Sensor Array Processing Workshop, MIT Lincoln Laboratory, Lexington, MA, Jun. 2005. Google Scholar

14. Moses, R. L., E. Ertin, and C. Austin, "Synthetic aperture radar visualization," Proceedings of the 38th Asilomar Conference on Signals, Systems, and Computers, Pacific Grove, CA, Nov. 2004. Google Scholar

15. Ertin, E., L. C. Potter, and R. L. Moses, "Enhanced imaging over complete circular apertures," Proceedings of the 40th Asilomar Conference on Signals, Systems, and Computers, Nov. 2006. Google Scholar

16. Ertin, E., R. L. Moses, and L. C. Potter, "Interferometric methods for three-dimensional target reconstruction with multipass circular SAR," Radar, Sonar and Navigation, IET, Vol. 4, No. 3, 464-473, 2010.
doi:10.1049/iet-rsn.2009.0048 Google Scholar

17., GTRI-dataset website: https://www.sdms.afrl.af.mil/datasets/gtri..
doi:10.1049/iet-rsn.2009.0048 Google Scholar

18. Showman, G. A., M. A. Richards, and K. J. Sangston, "Comparison of two algorithms for correcting zero-Doppler clutter in turntable ISAR imagery," Proceedings of the 32th Asilomar Conference on Signals, Systems, and Computers, Nov. 1998. Google Scholar

Dr. Lingjuan Yu

Prof. Yunhua Zhang