Characteristics of L-band multipath fading due to sea surface reflection

For low G/T ship-based earth stations in future maritime satellite communications, the effect of multipath fading due to sea surface reflection will be very important at low elevation angles. However, a practical model of the L -band multipath fading for fade prediction has not been available so far. A practical fading model is presented based on the shadowed Kirchhoff approximation theory for the coherent and incoherent components of the scattered power as a function of sea surface conditions. Using this model, theoretical fading depths are presented as a function of elevation angle, wave height, and antenna gain. The results indicate that intense fading occurs for wave heights greater than 50 cm, and the dependence on wave height is small under these conditions at L -band frequencies. Theoretical results presented agree well with experimental results obtained by field experiments.