Influence of sea surface roughness on the electromagnetic wave propagation in the duct environment

Brief review on PE method application to propagation channel modeling in sea environment

“…Even though tentative, this study shows: a) the PL differences of scores of dB due to surface ducting will affect the link budget and increase the requirements to the WCDMA power control range; b) depending on the specific climatic characteristics, the use of annually averaged (and even seasonally averaged) values for the duct parameters, which is a common practice, may be not enough for accurate PL prediction. Searching to improve the propagation modeling and increase the agreement between predicted and measured fields, a number of authors have combined the PE (1) with different RRFs and applied it to simulate over-sea propagation in various scenarios [112][113][114][115]. As discussed in Section 2.2, some recently proposed RRFs account for the shadowing caused by the sea surface roughness on electromagnetic waves propagating under grazing incidence angles.…”

“…The physics behind this profile, based on the Monin-Obukhov similarity theory, is explained elsewhere [7,108,109]. As indicated by Paulus and Anderson [111], (20) is a good practical approximation to the average M( ) profile, and has been widely used as input to the PE propagation model applied under evaporation duct conditions [27,33,40,73,97,[111][112][113][114][115]. Equation (20), however, has been obtained assuming thermally neutral troposphere stratification and does not account for the tropospheric stability effects on the M profile [7,29,33].…”

“…Further comparisons between (14), (15), and (16) and their effects on the PF and PL for the case of ducted propagation over the sea are reported in [114,115]. (14) and (15)) the nce between the direct and reflected fields.…”

“…Thus it may be expected that the accounting for the shadowing will increase the destructive effect of the sea roughness on the duct structure trapping capability, especially as far as the long-range ducted propagation is concerned. Further comparisons between (14), (15), and (16) and their effects on the PF and PL for the case of ducted propagation over the sea are reported in [114,115]. Benhmammouch et al [112] studied the influence of the wind direction on electromagnetic waves propagation over rough sea surface by hybridizing two approaches to the sea surface representation: (i) the large sea surface roughness is generated on the basis of a sea spectrum multiplied by an angular spreading function, thus introducing the angle difference between the wind direction and electromagnetic wave propagation direction; (ii) the small roughness is introduced by replacing the standard deviation σ ξ in (14) with the standard deviation of capillarity waves.…”

Oceanic propagation measurement in the Northern part of the South China Sea

“…As mentioned by Zhao [11], the reflected signal is subjected to sea surface roughness, which is related to wind speed. Thus, sea wind speed generally influences the received signal level on two levels: EVD condition and sea surface roughness.…”