In this paper, the subaperture approximation (SA) method for 3-D microwave imaging is presented based on the sparsity of 3-D image. The idea is that the sparsity information can be extracted from the lower resolution image obtained using the subaperture of the (virtual) array and be used for high-resolution imaging to reduce the imaging region. Thus, a recursion procedure that can significantly reduce the computational cost is established. Compared with the surface-tracing-based method, the SA method can avoid the loss of isolated scatterers. The feasibility is verified by using experimental data. After analysis, the SA method can reduce the computational cost from two aspects: reducing the array element number needed to be processed and the pixels needed to be processed. The computational cost is mainly related to the target characteristics (the sparsity ratio and the topological structure), and decreases with the increase of the sparsity ratio. When the sparsity ratio is larger than 97.6%, the computational cost can be lower than 10% of the 3-D back-projection (BP) method.
"Fast 3-D Microwave Imaging Method Based on Subaperture Approximation," Progress In Electromagnetics Research,
Vol. 126, 333-353, 2012. doi:10.2528/PIER12011106
1. Li, F., X. Chen, and K.-M. Huang, "Microwave imaging a buried object by the GA and using the S11 parameter," Progress In Electromagnetics Research, Vol. 85, 289-302, 2008. doi:10.2528/PIER08081401
2. Zhou, H., T. Takenaka, J. Johnson, and T. Tanaka, "A breast imaging model using microwaves and a time domain three dimensional reconstruction method," Progress In Electromagnetics Research, Vol. 93, 57-70, 2009. doi:10.2528/PIER09033001
3. Ren, X.-Z., L. H. Qiao, and Y. Qin, "A three-dimensional imaging algorithm for tomography SAR based on improved interpolated array transform," Progress In Electromagnetics Research, Vol. 120, 181-193, 2011.
4. Li, N.-J., C.-F. Hu, Y.-X. Zhao, and J. J. Wei, "A new method of near-field three dimensional synthetic aperture radar imaging," PIERS Proceedings, 71-74, Cambridge, USA, Jul. 5-8, 2010.
5. Li, C. and D.-Y. Zhu, "A residue-pairing algorithm for InSAR phase unwrapping," Progress In Electromagnetics Research, Vol. 95, 341-354, 2009. doi:10.2528/PIER09070706
6. Klare, J., "Digital beamforming for a 3D MIMO SAR --- Improvements through frequency and waveform diversity," IGARSS 2008, V17-V20, Boston, MA, United States, Jul. 2008.
7. Teng, H. T., H.-T. Ewe, and S. L. Tan, "Multifractal dimension and its geometrical terrain properties for classification of multiband multi-polarized SAR image," Progress In Electromagnetics Research, Vol. 104, 221-237, 2010. doi:10.2528/PIER10022001
8. Yu, L. and Y. Zhang, "CSAR imaging with data extrapolation and approximate GLRT techniques," Progress In Electromagnetics Research M, Vol. 19, 209-220, 2011. doi:10.2528/PIERM11062904
9. Chan, T.-K., Y. Kuga, and A. Ishimaru, "Experimental studies on circular SAR imaging in clutter using angular correlation function technique," IEEE Trans. Geoscience and Remote Sensing, Vol. 37, No. 5, 2192-2197, Part 1, Sep. 1999. doi:10.1109/36.789616
10. Bryant, M. L., L. L. Gostin, and M. Soumekh, "3-D E-CSAR imaging of a T-72 tank and synthesis of its SAR reconstructions," IEEE Trans. Aerospace and Electronic Systems, Vol. 39, No. 1, 211-227, Jan. 2003. doi:10.1109/TAES.2003.1188905
11. Axelsson, S. R. J., "Beam characteristics of the three-dimensional SAR in curved or random paths," IEEE Trans. Geoscience and Remote Sensing, Vol. 42, No. 10, 2324-2334, Oct. 2004. doi:10.1109/TGRS.2004.834802
12. Mahafza, B. R. and M. Sajjadi, "Three-dimensional SAR imaging using linear array in transverse motion," IEEE Trans. Aerospace and Electronic Systems, Vol. 32, No. 1, 499-510, Jan. 1996. doi:10.1109/7.481296
13. Jun, S., X. Zhang, J. Yang, and C. Wen, "APC trajectory design for one-active" linear-array three-dimensional imaging SAR," IEEE Trans. on Geoscience and Remote Sensing, Vol. 48, No. 3, 1470-1486, Mar. 2010. doi:10.1109/TGRS.2009.2031430
14. Du, L., et al., "A three-dimensional range migration algorithm for downward-looking 3D-SAR with single-transmitting and multiple receiving linear array antennas ," EURASIP Journal on Advances in Signal Processing, Vol. 2010, 1-15, 2010. doi:10.1155/2010/957916
15. Zhang, D.-H. and X.-L. Zhang, "Downward-looking 3-D linear array SAR imaging based on chirp scaling algorithm," 2nd Asian-Paci¯c Conference on Synthetic Aperture Radar, APSAR 2009, 1043-1046, 2009.
16. Shi, J., X. Zhang, J. Yang, and Y. Wang, "Surface-tracing-based LASAR 3-D imaging method via multiresolution approximation," IEEE Trans. Geoscience and Remote Sensing, Vol. 46, No. 11, Part 2, 3719-3730, Nov. 2008.
17. Jun, S., X. Zhang, J. Yang, and K. Liao, "Experiment results on one-active" LASAR," IEEE Radar Conference 2009, 1-4, Pasadena, CA, United States, May 2009.
18. Sheen, D., D. McMakin, and T. Hall, "Near-field three-dimensional radar imaging techniques and applications," Applied Optics, Vol. 49, No. 19, E83-E93, Jul. 2010. doi:10.1364/AO.49.000E83
19. Balanis, C. A., Antenna Theory: Analysis and Design, Wiley, 1997.
20. Ward Cheney, Will light, "A Course in Approximation Theory,", Brooks/Cole, Paci¯c Grove, CA, 2000.
21. Koo, V. C., Y. K. Chan, V. Gobi, M. Y. Chua, C. H. Lim, C.-S. Lim, C. C. Thum, T. S. Lim, Z. Bin Ahmad, K. A. Mahmood, M. H. Bin Shahid, and C., "A new unmanned aerial vehicle synthetic aperture radar for environmental monitoring ," Progress In Electromagnetics Research, Vol. 122, 245-268, 2011.
22. Wang, Y.-P., et al., "Effect of linear array elements spacing on angle imaging performance of downward-looking 3D-SAR," IGARSS 2009, IV570-IV573, Cape Town, South Africa, Jul. 2009.
23. Wei, S.-J., X.-L. Zhang, and J. Shi, "Linear array SAR imaging via compressed sensing," Progress In Electromagnetics Research, Vol. 117, 299-319, 2011.
24. Freeman, A. and S. L. Durden, "A three-component scattering model for polarimetric SAR data," IEEE Trans. on Geoscience and Remote Sensing, Vol. 36, No. 3, 953-973, May 1998. doi:10.1109/36.673687
25. Yamaguchi, Y., T. Moriyama, M. Ishido, and H. Yamada, "Four-component scattering model for polarimetric SAR image decomposition," IEEE Trans. on Geoscience and Remote Sensing, Vol. 43, No. 8, 1699-1706, Aug. 2005. doi:10.1109/TGRS.2005.852084
26. Franceschetti, G., A. Iodice, and D. Riccio, "A canonical problem in electromagnetic backscattering from buildings," IEEE Trans. on Geoscience and Remote Sensing, Vol. 40, No. 8, 1787-1801, Aug. 2002. doi:10.1109/TGRS.2002.802459
27. Ausherman, D., A. Kozma, J. Walker, H. Jones, and E. Poggio, "Developments in radar imaging," IEEE Trans. Aerospace and Electronic Systems, Vol. 363, Jul. 20, 1984.
28. Socas-Navarro, H., "Polarimetric calibration of large-aperture telescopes II: The sub-aperture method," J. Opt. Soc. Am. A, Vol. 22, 907-912, 2005. doi:10.1364/JOSAA.22.000907