volume | PIER Journals

Abstract

Range alignment plays an important role in the inverse synthetic aperture radar (ISAR) imaging. The performance of the traditional range alignment algorithms decreases when the migration through resolution cells (MTRC) is much severe. In this paper, a measure of MTRC is defined, and the effect of MTRC on range alignment is analyzed. Taking MTRC into account, a robust sub-integer range alignment algorithm is proposed. Firstly, each range profile is interpolated to remove the precision limitation of integer range resolution cell. Subsequently, the matrix formed by all the range profiles is partitioned into several matrix blocks on the slow-time domain. For each matrix block, the range profiles are aligned by minimizing the entropy of the average range profile (ARP). Finally, the matrix blocks are coarsely aligned using the maximum correlation method, followed by a fine alignment based on the minimization of the ISAR image entropy. The effectiveness of the proposed algorithm is validated by simulations and real-world data. Results demonstrate that the proposed method is robust against MTRC and can reduce the alignment error. The resultant ISAR image is much better focused.

1. Chen, C. C. and H. C. Andrews, "Target-motion-induced radar imaging," IEEE Trans. Aerosp. Electron. Syst., Vol. 16, No. 1, 2-14, 1980.
doi:10.1109/TAES.1980.308873

2. Martorella, M., E. Giusti, A. Capria, et al. "Automatic target recognition by means of polarimetric ISAR images and neural networks," IEEE Trans. Geosci. Remote Sens., Vol. 47, No. 11, 3786-3794, 2009.
doi:10.1109/TGRS.2009.2025371

3. Musman, S., D. Kerr, and C. Bachmann, "Automatic recognition of ISAR images," IEEE Trans. Aerosp. Electron. Syst., Vol. 35, No. 4, 1240-1252, 1999.
doi:10.1109/7.805442

4. Yan, X., J. Hu, G. Zhao, J. Zhang, and J. Wan, "A new parameter estimation method for GTD model based on modified compressed sensing," Progress In Electromagnetics Research, Vol. 141, 553-575, 2013.
doi:10.2528/PIER13052017

5. Park, J.-I. and K.-T. Kim, "A comparative study on ISAR imaging algorithms for radar target identification," Progress In Electromagnetics Research, Vol. 108, 155-175, 2010.
doi:10.2528/PIER10071901

6. Munoz-Ferreras, J. M. and F. Perez-Martinez, "Subinteger range-bin alignment method for ISAR imaging of noncooperative targets," EURASIP J. Adv. Signal Process., Vol. 2010, 1-16, 2010.

7. Yuan, B., S. Y. Xu, and Z. P. Chen, "Translational motion compensation techniques in ISAR imaging for target with micro-motion parts," Progress In Electromagnetics Research M, Vol. 35, 113-120, 2014.
doi:10.2528/PIERM14011503

8. Zhu, D. Y., L. Wang, Y. S. Yu, et al. "Robust ISAR range alignment via minimizing the entropy of the average range profile," IEEE Geosci. Remote Sens. Lett., Vol. 6, No. 2, 204-208, 2009.
doi:10.1109/LGRS.2008.2010562

9. Wang, G. Y. and Z. Bao, "A new algorithm of range alignment in ISAR motion compensation," Acta Electronica Sinica, Vol. 26, No. 6, 5-8, 1998.

10. Wang, J. F. and D. Kasilingam, "Global range alignment for ISAR," IEEE Trans. Aerosp. Electron. Syst., Vol. 39, No. 1, 351-357, 2003.
doi:10.1109/TAES.2003.1188917

11. Steinberg, B. D., "Microwave imaging of aircraft," Proceedings of the IEEE, Vol. 16, No. 12, 1578-1592, 1988.
doi:10.1109/5.16351

12. Ye, C. M., J. Xu, Y. N. Peng, et al. "Performance analysis of Doppler centroid tracking for ISAR autofocusing," Acta Electronica Sinica, Vol. 37, No. 6, 1324-1328, 2009.

13. Jackowatz, C., D. Wahl, P. Eichel, et al. Spotlight-mode Synthetic Aperture Radar: A Signal Processing Approach, Kluwer Academic Publishers, 1996.
doi:10.1007/978-1-4613-1333-5

14. Zhang, L., J. L. Sheng, J. Duan, et al. "Translational motion compensation for ISAR imaging under low SNR by minimum entropy," EURASIP J. Adv. Signal Process., Vol. 2013, 1-19, 2013.

15. Li, X., G. S. Liu, and J. L. Ni, "Autofocusing of ISAR images based on entropy minimization," IEEE Trans. Aerosp. Electron. Syst., Vol. 35, No. 4, 1240-1252, 1999.
doi:10.1109/7.805442

16. Qiu, X. H., A. H. W. Cheng, and Y. S. Yam, "Fast minimum entropy phase compensation for ISAR imaging," Journal of Electronics and Information Technology, Vol. 26, No. 10, 1656-1660, 2004.

17. Xu, G., M. D. Xing, L. Yang, et al. "Joint approach of translational and rotational phase error corrections for high-resolution inverse synthetic aperture radar imaging using minimum-entropy," IET Radar Sonar Navig., Vol. 10, No. 3, 586-594, 2016.
doi:10.1049/iet-rsn.2015.0356

18. Martorella, M., J. Palmer, F. Berizzi, et al. "Polarimetric ISAR autofocusing," IETSignal Process., Vol. 2, No. 3, 312-324, 2008.

19. Zhang, S. H., Y. X. Liu, and X. Li, "Fast entropy minimization based autofocusing technique for ISAR imaging," IEEE Trans. Signal Process., Vol. 63, No. 13, 3425-3434, 2015.
doi:10.1109/TSP.2015.2422686

20. Martorella, M., F. Berizzi, and B. Haywood, "Contrast maximisation based technique for 2-D ISAR autofocusing," IEE Proceedings: Radar Sonar Navig., Vol. 152, No. 4, 253-262, 2005.
doi:10.1049/ip-rsn:20045123

21. Xing, M. D., R. B. Wu, and Z. Bao, "High resolution ISAR imaging of high speed moving targets," IEE Proceedings: Radar Sonar Navig., Vol. 152, No. 2, 58-67, 2005.
doi:10.1049/ip-rsn:20045084

22. Ozdemir, C., Inverse Synthetic Aperture Radar Imaging with MATLAB Algorithms, John Wiley and Sons, Inc., 2012.
doi:10.1002/9781118178072

Dr. Pengjiang Hu

Dr. Shiyou Xu

Dr. Zengping Chen