volume | PIER Journals

Abstract

Classical assesssment of the received power by a radar leads to a decorrelation of many relevant phenomena (i.e. propagation, backscattering), which may introduce modelling errors notably in the presence of large target with respect to the wavelength. To overcome this limitation, a new hybrid approach is proposed. It combines a method of propagation calculation (the parabolic wave equation) with a method of scattering calculation (the EFIE solved by a method of moment approach) and an application of the reciprocity principle (the power coupling factor). Each method constituting the hybrid approach is described; the example of a large cargo is chosen and its apparent RCS is evaluated above the sea at low frequency. The results are discussed, studying the influence of the different parts of the boat on the apparent RCS.

1. "Special section on over-the-horizon radar technology," Radio Science, Vol. 33, No. 7, 1043-1266, 1998.
doi:10.1029/98RS02158

2. King, W. P., "Surface-wave radar and its application," IEEE Transactions on Antennas and Propagation, Vol. 51, No. 10, 2003.
doi:10.1109/TAP.2003.817991

3. Sevgi, L., A. Ponsford, and C. H. Chan, "An integrated marine surveillance system based on high-frequency surface wave radars, Part 1: Theoretical background and numerical simulations," IEEE Antennas and Propagation Magazine, Vol. 43, No. 4, 2001.

4. Sevgi, L., "Stochastic modelling of target detection and tracking in surface HF radar," Int. Journal Num. Model., No. 11, 167-181, 1998.
doi:10.1002/(SICI)1099-1204(199805/06)11:3<167::AID-JNM300>3.0.CO;2-W

5. Khan, R., et al. "Target detection and tracking with a high frequency ground wave radar," IEEE J. Oceanic Eng., Vol. 19, No. 4, 1994.
doi:10.1109/48.338390

6. Patterson, W. L., Advanced Refractive Effects Prediction System (AREPS), 92152-5001, Version 1.0 Users Manual, 1998.

7. Levy, M. F. and K. H. Craig, "TERPEM propagation package for operational forecasting with EEMS," Proceedings of the 1996 Battlespace Atmospherics Conference, 1996.

8. Fabbro, V., N. Guillet, and P. F. Combes, "Innovative improvements of the Parabolic Wave Equation method for radiowave propagation modeling," ICAP 2003, 2003.

9. Simon, J., "Extension des mÃ©thodes multipoles rapides: rÃ©solution pour des seconds membres multiples et applications aux objets diÃ©lectriques," Ph.D. thesis, No. 6, 2003.

10. Chew, W. C., J. M. Jin, and C. C. Lu, "Fast solutions methods in electromagnetics," IEEE Transactions on Antennas and Propagation, Vol. 45, No. 3, 533-543, 1997.
doi:10.1109/8.558669

11. Burkholder, R. J., M. R. Pino, and F. Obelleiro, "A Monte Carlo study of the rough sea surface influence on the radar scattering from two dimensional ships," IEEE Antennas and Propagation Magazine, Vol. 43, No. 2, 2001.
doi:10.1109/74.924601

12. Bolomey, J. C., "RÃ©ponse d'une antenne de rÃ©ception une onde incidente non plane," Annales des TÃ©lÃ©com., Vol. 34, 469-476, 1979.

13. Fabbro, V., N. Douchin, and P. F. Combes, "Three-dimensional backscatering by a target above the sea surface," Electromagnetics, Vol. 21, No. 6, 451-466, 2001.
doi:10.1080/027263401750399534

14. Dockery, G. D. and J. R. Kuttler, "An improved-boundary algorithm for Fourier split-step solutions of the parabolic wave equation," IEEE Trans. Antennas and Propag., Vol. 44, No. 12, 1592-1599, 1996.
doi:10.1109/8.546245

15. Kuttler, J. R. and R. Janaswamy, "Improved Fourier transform methods for solving the parabolic wave equation," Radio Science, Vol. 37, No. 2, 2002.
doi:10.1029/2001RS002488

16. Donohue, J. and J. R. Kuttler, "Propagation modeling over terrain using the parabolic wave equation," IEEE Trans. Antennas and Propag., Vol. 48, No. 2, 260-277, 2000.
doi:10.1109/8.833076

17. Leontovitch, A., "On the approximate boundary conditions for an electromagnetic filed on the surface of well-conducting bodies, investigations of propagation of radio waves," Academy of Science, 1948.

18. Barrick, D. E., "Theory of HF and VHF propagation across the rough sea, 1. The effective surface impedance for a slightly rough highly conducting medium at grazing incidence," Radio Science, Vol. 6, 517-526, 1971.

19. Barrick, D. E., "Theory of HF and VHF propagation across the rough sea, 2. Application to HF and VHF propagation above the sea," Radio Science, Vol. 6, 527-533, 1971.

20. Phillips, O. M., "Spectral and statistical properties of the equilibrium range in wind generated gravity waves," J. Flui. Mech., Vol. 156, 505-531, 1985.
doi:10.1017/S0022112085002221

21. Millington, G. and G. A. Isted, "Ground-wave propagation over an inhomogeneous smooth earth: Part 2. Experimental evidence and practical implementation," Proc. IEE, Vol. 97, 209-221, 1950.

22. Wu, Z., et al. "Recovery effect in radiowave propogation," Electronic Letters, No. 3, 162-163, 1990.

23. Norton, K. A., "The propagation of radio waves over the surface of the earth and in upper atmosphere," Proc. IRE, Vol. 25, 1203-1236, 1937.

24. Maclean, T. S. M. and Z. Wu, "Radiowave propagation over ground," Chapman and Hale, 1993.

25. Fabbro, V., "Diffraction d'une onde Ã©lectromagnÃ©tique par une cible plongÃ©e dans un milieu hÃ©tÃ©rogÃ¨ne. Application la dÃ©tection radar basse altitude au-dessus de la mer," Ph.D. thesis, No. 10, 1999.

26. Soudais, P., H. Steve, and F. Dubois, "Scattering from several test-ob jects computed by 3D hybrid IE/PDE methods," IEEE Trans. Antennas and Propag., Vol. 47, No. 4, 646-653, 1999.
doi:10.1109/8.768803

27. Knott, E. F., J. F. Shaeffer, and M. T. Tuley, Radar Cross Section, Artech House, 1985.

28. Moore, J. and R. Pizer, Moment Methods in Electromagnetics, Research Studies Press LTD, 1984.

Dr. Vincent Fabbro

Prof. Paul Combes

Dr. Nicolas Guillet