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Progress In Electromagnetics Research C
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DIGITAL BEAMFORMING IN ELEVATION FOR MOVING SURFACE SHIPS

By L. Zhang and Y. Jiang

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Abstract:
Moving target ship imaging in large sea area has always been the focus of military and civilian attention. Due to the limitation of pulse repetition frequency (PRF), there is a contradiction between wide mapping band and azimuth accuracy. The nonlinearity of PRF can also cause discontinuity of mapping band. Therefore, this paper proposes a method of digital beamforming-scan on receiving (DBF-SCORE) beam scanning based on airborne phased array radar to achieve the requirement of scene mapping band with lower PRF. The adaptive Capon spectrum estimation is used to dynamically adjust the beam pointing so that it can always point to the moving target for accurate imaging. Considering the nonuniform sampling of the transmitting pulse period of the antenna, the azimuth nonuniform Fourier transform (NUDFT) algorithm is used to re-sample the nonuniform periodic signal of the multi-channel receiving antenna and obtain the uniform spectrum signal. Finally, fine focusing of moving target is achieved by local phase gradient algorithm (PGA) algorithm, and accurate imaging of moving target in large sea area is realized. The validity of the algorithm can be verified by simulation and real data imaging, which can be used for reference in phased array SAR imaging of moving targets.

Citation:
L. Zhang and Y. Jiang, "Digital Beamforming in Elevation for Moving Surface Ships," Progress In Electromagnetics Research C, Vol. 94, 177-187, 2019.
doi:10.2528/PIERC19041204

References:
1. Heimmer, J., "Multi-mission phased array radar (MPAR) national radar R&D project," Systems, Applications & Technology Conference, 1-2, IEEE Long Island, 2008.

2. Zhang, S. X., et al., "Multichannel HRWS SAR imaging based on range-variant channel calibration and multi-Doppler-direction restriction ambiguity suppression," IEEE Transactions on Geoscience and Remote Sensing, Vol. 52, No. 7, 4306-4327, 2014.
doi:10.1109/TGRS.2013.2281329

3. Reigber, A., et al., "DBFSAR: An airborne very high-resolution digital beamforming SAR system," Proceedings of the 14th European Radar Conference, 175-178, Nuremberg, Germany, Oct. 2017.

4. Sikaneta, I. and D. Cerutti-Maori, "Demonstrations of HRWS and GMTI with RADARSAT-2," European Conference on Synthetic Aperture Radar, 263-266, Nuremberg, Germany, Apr. 2012.

5. Reigber, A., et al., "DBFSAR: An airborne very high-resolution digital beamforming SAR system," European Radar Conference (EuRAD), 175-178, 2017.

6. Cook, C. E. and M. Bernfeld, Radar Signal an Introduction to Theory and Application, Academic Press, 1967.

7. Capon, J., "High-resolution frequency-wavenumber spectral analysis," Proc. IEEE, Vol. 57, 1408-1418, 1969.
doi:10.1109/PROC.1969.7278

8. Zhang, C., Synthet Icaperture Radar: Theorysystem Analysis and Application, Science Press, Beijing, 1989.

9. Dutt, A. and V. Rokhlin, "Fast Fourier transforms for nonequispaced data," SIAM Journal on Scientific Computing, Vol. 14, No. 6, 1368-1393, 1993.
doi:10.1137/0914081

10. Fessler, J. A. and B. P. Sutton, "Nonuniform fast Fourier transforms using min-max interpolation," IEEE Transactions on Signal Processing, Vol. 51, No. 2, 560-574, 2003.
doi:10.1109/TSP.2002.807005

11. Liu, Q. H. and N. Nguyen, "An accurate algorithm for nonuniform fast Fourier transforms (NUFFT's)," IEEE Microwave and Guided Wave Letters, Vol. 8, No. 1, 18-20, 2002.
doi:10.1109/75.650975

12. Ren, B. L., et al., "A fast circular convolution algorithm based on NUFFT for near-field SAR imaging," International Conference on Microwave & Millimeter Wave Technology, 1-4, 2012.

13. Wu, Y., et al., "Improved RMA based on Nonuniform Fast Fourier Transforms (NUFFT's)," International Conference on Signal Processing, 2489-2492, 2008.

14. Zhao, X., X. L. Wang, and Z. M. Wang, "Phase gradient autofocus algorithm for SAR images based on optimal contrast criterion," Remote Sensing Technology and Application, Vol. 20, No. 6, 606-610, 2005.

15. Ye, C., et al., "Parallel implementation of a block-wise phase gradient autofocusing method," J. Tsinghua Univ. (Sci. & Tech.), Vol. 52, No. 5, 612-615, 2012.


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