Inverse Synthetic Aperture Radar (ISAR) imaging is one of the most sophisticated methods to obtain information about the scattering or radiation properties of a finite sized object. The idea is to process the scattered or radiated fields coherently over a certain frequency bandwidth and over a certain angular range in order to generate the image. In a simulation based approach, this procedure can be considerably simplified, if the source currents are known (either real or equivalent) and if a bistatic image is desired. By inserting the radiation integral into the imaging integral and by interchanging the integration orders, the imaging point spread function can be generated and the image formation is reduced to a convolution of the point spread function with the current distribution. A concise formulation of this well-known methodology is presented together with a discussion of important properties. Various examples of 2D and 3D images for complex metallic objects such as automobiles are shown, which have been obtained from the surface currents of a Shooting and Bouncing Rays (SBR) field solver.
2. Bhalla, R. and H. Ling, "ISAR image formation using bistatic data computed from the shooting and bouncing ray technique," Journal of Electromagnetic Waves and Applications, Vol. 7, No. 9, 1271-1287, 1993.
3. Peterson, A. F., S. S. Ray, and R. Mittra, Computational Methods for Electromagnetics, IEEE Press, Piscataway, 1998.
4. Eibert, T. F., "A diagonalized multilevel fast multipole method with spherical harmonics expansion of the k-space integrals ," IEEE Trans. Antennas Propag., Vol. 53, No. 2, 814-817, Feb. 2005.
5. Ling, H., R.-C. Chou, and S.-W. Lee, "Shooting and bouncing rays: Calculating the RCS of an arbitrarily shaped cavity," IEEE Trans. Antennas Propag., Vol. 37, No. 2, 194-205, Feb. 1989.
6. Buddendick, H. and T. F. Eibert, "Acceleration of ray-based radar cross section predictions using monostatic-bistatic equivalence," IEEE Trans. Antennas Propag., Vol. 58, No. 2, 531-539, Feb. 2010.
7. Lee, S. W., H. Ling, and R. Chou, "Ray tube integration in shooting and bouncing ray method," Microwave Opt. Tech. Lett., Vol. 1, 286-289, Oct. 1988.
8. Bhalla, R. and H. Ling, "Image-domain ray-tube integration formula for the shooting and bouncing ray technique," Radio Science, Vol. 30, 1435-1446, Sep./Oct. 1995.
9. Bhalla, R. and H. Ling, "A fast algorithm for signature prediction and image formation using the shooting and bouncing ray technique," IEEE Trans. Antennas Propag., Vol. 43, No. 11, 727-731, Jul. 1995.
10. Bhalla, R. and H. Ling, "Three-dimensional scattering center extraction using the shooting and bouncing ray technique," IEEE Trans. Antennas Propag., Vol. 44, No. 11, 1445-1453, Nov. 1996.
11. Bhalla, R., J. Moore, and H. Ling, "A global scattering center representation of complex targets using the shooting and bouncing ray technique," IEEE Trans. Antennas Propag., Vol. 45, No. 12, 1850-1856, Dec. 1997.
12. Bhalla, R. and H. Ling, "Near-field signature prediction using far-field scattering centers extracted from the shooting and bouncing ray technique," IEEE Trans. Antennas Propag., Vol. 48, No. 2, 337-338, Feb. 2000.
13. Wang, X. B., X. Y. Zhou, T. J. Cui, Y. B. Tao, and H. Lin, "High-resolution inverse synthetic aperture radar imaging based on the shooting and bouncing ray method," Global Symposium on Millimeter Waves, Nanjing, China, 2008.
14. He, X. Y., X. B. Wang, Y. Y. Zhou, B. Zhao, and T. J. Cui, "Fast ISAR imag simulation of targets at arbitrarily aspect angles using a novel SBR method," Progress In Electromagnetics Research B, Vol. 28, 129-142, 2011.
15. Anglberger, H., R. Speck, T. Kempf, and H. Suess, "Fast ISAR image generation through localization of persistent scattering centers," Proc. SPIE, Defense & Security, Orlando, FL, USA, Apr. 2009.
16. Buddendick, H. and T. F. Eibert, Application of a fast equivalent currents based algorithm for scattering center visualization of vehicles, IEEE Antennas and Propagation International Symposium, Toronto, Ca, 2010.
17. Buddendick, H. and T. F. Eibert, Parallelized physical optics computations for scattering center models in radio channel simulations, IEEE Vehicular Network Conference, 2010.
18. Yu, Y., D. Zhang, Z. Yin, and W. Chen, "Broadband electro-magnetic scattering echo generation and its ISAR imaging simulation," International Conference on Microwave and Millimeter Wave Technology, Nanjing, China, 2008.
19. Le, C., T. Dogaru, L. Nguyen, and M. A. Ressler, "Ultrawideband (UWB) radar imaging of building interior: Measurements and predictions ," IEEE Transactions on Geoscience and Remote Sensing, Vol. 47, No. 5, 1409-1419, May 2009.
20. Kong, J. A., Electromagnetic Wave Theory, Wiley, New York, 1990.
21. Bleistein, N. and J. K. Cohen, "Nonuniqueness in the inverse source problem in acoustics and electromagnetic," Journal of Mathematical Physis, Vol. 18, No. 2, 194-201, Feb. 1977.
22. Abramowitz, M. and I. A. Stegun, Handbook of Mathematical Functions, 10th Ed., Dover Publications, 1972.
23. Bhalla, R. and H. Ling, "Cross range streaks in ISAR images generated via the shooting and bouncing ray technique: Cause and solutions," IEEE Antennas Propag. Mag., Vol. 39, No. 2, 76-80, Apr. 1997.