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

The distance of conventional X-band microwave propagation over the sea surface is within 'radio line-of-sight' (RLOS) which limits its application in long-range land-buoy communication. To overcome the above limitation, evaporation duct (EVD) is employed as an alternative to the physical channel in the land-buoy communication and the corresponding communication distance could be extended to hundreds of kilometers. To explore the effects of EVD channels on communication signaling, an over-the-sea trans-horizon propagation experiment was conducted in the northern part of the South China Sea. The statistical features of the received signal level (RSL), e.g. median, fading range, and probability density function (PDF), are reported. Moreover, the influence of sea surface wind speed and the height of the receiving terminals on RSL fluctuation are also discussed. Finally, Some conclusions are given.