The performance assessment of maritime microwave communications and radar systems requires accounting simultaneously for the non-homogeneous propagation medium over the sea and the rough sea surface scattering. The tropospheric ducting, specific for over water propagation, is one of the most difficult to treat propagation mechanisms. The proposed work combines a recently published in the literature phase correction, responsible for the shadowing effects, to the Ament rough surface reflection coefficient and the Parabolic Equation method (as implemented in the Advanced Propagation Model) to simulate the microwave propagation over the sea under evaporation duct conditions. Propagation factor and path loss results calculated for phase-corrected Ament, non-phase-corrected Ament and the other widely used, Miller-Brown, rough surface reflection coefficient are compared and discussed. The main effects from the accounting of the shadowing result in the shift of the interference minima and maxima of the propagation factor, changes in the path loss pattern and destruction of the trapping property of the duct.
2. Kerr, D. E., Propagation of Short Radio Waves, Peninsula Publishing, Los Altos, 1988.
3. Lopez, P. H., "A 5-yr 40-km-resolution global climatology of superrefraction for ground-based weather radars," J. Appl. Meteor. Climatol., Vol. 48, 89-110, Jan. 2009.
4. Anderson, K. D., "Radar detection of low-altitude targets in a maritime environment," IEEE Trans. Antennas Propag., Vol. 43, No. 6, 609-613, Jun. 1995.
5. Woods, G. S., A. J. Kerans, and D. L. Maskell, "Simulated angle-of-arrival measurements for an over ocean microwave radio link," Proc. URSI Commission F Triennium Open Symposium, 200-207, Cairns, Australia, Jun. 2004.
6. Barrios, A. E. , K. Anderson, and G. Lindem, "Low altitude propagation effects --- A validation study of the advanced propagation model (APM) for mobile radio applications," IEEE Trans. Antennas Propag., Vol. 54, No. 10, 2869-2877, Oct. 2006.
7. Sirkova, I. and M. Mikhalev, "Parabolic-equation-based study of ducting effects on microwave propagation," J. Microw. Opt. Technol. Letters, Vol. 42, No. 5, 390-394, Sep. 2004.
8. Gunashekar, S. D., E. M. Warrington, D. R. Siddle, and P. Valtr, "Signal strength variations at 2 GHz for three sea paths in the British channel islands: Detailed discussion and propagation modeling," Radio Sci., Vol. 42, RS4020, Aug. 2007, doi: 10.1029/2006RS003617.
9. Babin, S. M. , G. S. Young, and J. A. Carton, "A new model for the oceanic evaporation duct," J. Appl. Meteor., Vol. 36, No. 3, 193-204, Mar. 1997.
10. Von Engeln, A. and J. Teixeira, "A ducting climatology derived from ECMWF global analysis fields," J. Geophys. Res., Vol. 109, D18104, Sep. 2004, doi: 10.1029/2003JD004380.
11. ITU-R P.452-11, "Prediction procedure for the evaluation of microwave interference between stations on the surface of the earth at frequencies above about 0.7 GHz,", 38, ITU, 2003.
12. Milas, V. F. and P. H. Constantinou, "Interference environment between high altitude platform networks (HAPN), geostationary (GEO) satellite and wireless terrestrial systems," Wireless Personal Communications, Vol. 32, No. 3-4, 257-274, Feb. 2005.
13. Kuttler, J. R. and G. D. Dockery, "Theoretical description of the parabolic approximation/fourier split-step method of representing electromagnetic propagation in the troposphere," Radio Sci., Vol. 26, No. 2, 381-393, Mar.-Apr. 1991.
14. Levy, M., Parabolic Equation Methods for Electromagnetic Wave Propagation , The Institution of Electrical Engineers, London, UK, 2000.
15. Donohue, D. J. and J. R. Kuttler, "Propagation modeling over terrain using the parabolic wave equation," IEEE Trans. Antennas Propag., Vol. 48, No. 2, 260-277, Feb. 2000.
16. Barrios, A., "A terrain parabolic equation model for propagation in the troposphere," IEEE Trans. Antennas Propag., Vol. 42, No. 1, 90-98, Jan. 1994.
17. Sirkova, I. and M. Mikhalev, "Parabolic wave equation method applied to the tropospheric ducting propagation problem --- A survey," Electromagnetics, Vol. 26, No. 2, 155-173, Feb. 2006.
18. Ament, W. S., "Toward a theory of reflection by a rough surface," Proc. IRE, Vol. 41, No. 1, 142-146, Jan. 1953.
19. Miller, A. R. , R. M. Brown, and E. Vegh, "New derivation for the rough surface reflection coefficient and for the distribution of sea-wave elevations," IEE Proc. Microwaves, Optics and Antennas, Vol. 131, Part H, No. 2, 114-116, Apr. 1984.
20. Freund, D. E., N. E. Woods, H.-C. H. Ku, and R. S. Awadallah, "Forward radar propagation over a rough sea surface: A numerical assessment of the Miller-Brown approximation using a horizontally polarized 3-GHz line source," IEEE Trans. Antennas Propag., Vol. 54, No. 4, 1292-1304, Apr. 2006.
21. Hristov, T. S., K. D. Anderson, and C. A. Friehe, "Scattering properties of the ocean surface: The Miller-Brown-Vegh model revisited," IEEE Trans. Antennas Propag., Vol. 56, No. 4, 1103-1109, Apr. 2008.
22. Freund, D. E., N. E. Woods, H.-C. Ku, and R. S. Awadallah, "The effects of shadowing on modelling forward radar propagation over a rough sea surface," Waves in Random and Complex Media, Vol. 18, No. 3, 387-408, Aug. 2008.
23. Fabbro, V. , C. Bourlier, and P. F. Combes, "Forward propagation modelling above Gaussian rough surfaces by the parabolic wave equation: Introduction of the shadowing effect," Progress In Electromagnetics Research, Vol. 58, 243-269, 2006.
24. Barrios, A. E. and W. L. Patterson, "Advanced propagation model (APM) Computer software configuration item (CSCI) documents," Space and Naval Warfare Systems Command Tech., Doc. 3145, 479, San Diego, CA, 2002.
25. Awadallah, R. S., "Rough surface scattering and propagation over rough terrain in ducting environments,", Doctoral Dissertation, 189, Virginia Polytechnic Institute and State University, Blacks-burg, Virginia, 1998.
26. Apaydin, G. and L. Sevgi, "The split-step-fourier and finite-element based parabolic-equation propagation prediction tools: Canonical tests, systematic comparisons, and calibration," IEEE Antennas Propag. Magazine, Vol. 52, No. 3, 66-79, Jun. 2010.
27. Dockery, G. D. and J. R. Kuttler, "An improved impedance-boundary algorithm for Fourier split-step solutions of the parabolic wave equation," IEEE Trans. Antennas Propag., Vol. 44, No. 12, 1592-1599, Dec. 1996.
28. Recommendations and Reports of the CCIR, "Propagation in non-ionized media," CCIR XVth Plenary Assembly, Vol. 5, ITU, Geneva, Dubrovnik, 1986.
29. Rotheram, S., "Radiowave propagation in the evaporation duct," Marconi Review, Vol. 37, No. 192, 18-40, 1974.
30. Paulus, R. A. and K. D. Anderson, "Application of an evaporation duct climatology in the littoral," Proc. Battlespace Atmospheric and Cloud Impacts on Military Operations, BACIMO, 1-9, Fort Collins, Colorado, Apr. 2000.
31. Smith Jr., J. R., S. J. Russell, B. E. Brown, P. M. Haldeman Jr., D. D. Hayden, D. G. Morgan, R. D. Pierce, J. W. Shan, "Electromagnetic forward-scattering measurements over a known, controlled sea surface at low grazing," IEEE Trans. Geosci. Remote Sensing, Vol. 42, No. 6, 1197-1207, Jun. 2004.
doi: --- Either ISSN or Journal title must be supplied.