A Study on the Propagation Characteristics of AIS Signals in the Evaporation Duct Environment
Keywords:
AIS, evaporation duct,, parabolic equation method, propagation lossAbstract
The propagation characteristics of signal of the Automatic Identification System (AIS) in the evaporation duct environment over the sea surface are investigated by using the parabolic equation method. The parabolic equation method has excellent stability and accuracy in solving the computational problem of electromagnetic wave propagation under different atmospheric conditions and it is probably the most suitable for the purpose of analyzing AIS signals. The propagation of AIS signals in air is determined by the variation of the refractivity with height. For AIS transmission, ducting propagation may be the most important propagation mechanism. The propagation loss of AIS signals in the evaporation duct is calculated and compared with that for the case of the standard atmosphere. In order to demonstrate the effect of evaporation duct on the propagation of AIS signals more intuitively, propagation loss versus range for three typical AIS links and the receiver height versus propagation loss under different atmospheric conditions are analyzed in details. The simulation results show that the evaporation duct has little influence on the AIS system.
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References
A. Goudossis and S. K. Katsikas, “Towards a secure automatic identification system (AIS),” J. Mar. Sci. Technol., https://doi.org/10.1007/s00773- 018-0561-3, 2018.
“Long range detection of automatic identification system (AIS) messages under various tropospheric propagation conditions,” Tech. Rep. ITU-R M. 2123, International Telecommunications Union (ITU), 2007.
D. Green, C. Fowler, D. Power, and J. Tunaley, “VHF propagation study,” Contractor report DRDC-ATLANTIC-CR-2011-152, Defense R&D Canada, London Research and Development Corp., C-Core, 2012.
E. R. Bruin, “On propagation effects in maritime situation awareness: Modelling the impact of North Sea weather conditions on the performance of AIS and coastal radar systems,” Master Thesis, Utrecht University, 2016.
H. Hitney and R. Vieth, “Statistical assessment of evaporation duct propagation,” IEEE Trans. Antennas Propagat., vol. 38, no. 6, pp. 794-799, 1990.
S. D. Gunashekar, D. R. Siddle, and E. M. Warrington, “Transhorizon radiowave propagation due to evaporation ducting,” Resonance, vol. 11, no. 1, pp. 51-62, 2006.
I. Sirkova, “Brief review on PE method application to propagation channel modeling in sea environment,” Cent. Eur. J. Eng., vol. 2, no. 1, pp. 19-38, 2012.
J. R. Kuttler and R. Janaswamy, “Improved Fourier transform methods for solving the parabolic wave equation,” Radio Science, vol. 37, no. 2, pp. 5-11, 2002.
Z. S. Wu, L. Li, L. K. Lin, and Z. W. Zhao, “Study on the maximum calculation height and the maximum propagation angle of the troposcatter wide-angle parabolic equation method,” IET Microwaves, Antennas & Propagation, vol. 10, no. 6, pp. 686-691, 2016.
Safety of life at sea (SOLAS) convention chapter V, regulation 19, 2000.
“Recommendation, technical characteristics for an automatic identification system using time division multiple access in the VHF maritime mobile band,” Tech. Rep. Rec. ITU-R M.1371-5, International Telecommunications Union (ITU), 2014.
R. A. Paulus, “Evaporation duct effects on sea clutter,” IEEE Trans. Antennas Propagat., vol. 38, no. 11, pp. 1765-1771, 1990.
M. Levy, Parabolic Equation Methods for Electromagnetic Wave Propagation, The Institution of Electrical Engineers, London, 2000.
I. Sirkova, “Propagation factor and path loss simulation results for two rough surface reflection coefficients applied to the microwave ducting propagation over the sea,” Progress n Electromagnetics Research M, vol. 17, pp. 151-166, 2011.
D. E. Freud, N. E. Woods, H. C. 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 Propagat., vol. 54, no. 4, pp. 1292-1304, 2006.
M. D. Cui, H. Cha, and B. Tian, “A propagation model for rough sea surface conditions using the parabolic equation with the shadowing effect,” ACES Journal, vol. 33, no. 6, pp. 683-689, 2018.
P. E. Cadette, “Modeling tropospheric radiowave propagation over rough sea surfaces using the parabolic equation Fourier split-step method,” Master thesis, The George Washington University, 2012.
