Assessment of millimeterwave propagation over sea by experiment and simulation

To be able to assess the capability of maritime radars under different conditions at differing radar bands simulation programs for the refractivity profile of the atmosphere and the wave propagation, based upon a solution of the parabolic equation have been developped. These have been used to model the propagation for a series of measurements which have been conducted using an experimental radar operating simultaneously at frequencies of 10 GHz, 35 GHz and 94 GHz against reference reflectors onboard a vessel for outbound and inbound courses. Simultaneously environmental measurements using wavebuoys and meteosonds have been conducted to generate a complete data set. Moreover an approach was initiated to retrieve the vertical profile of the refractive index from sea clutter data by an inversion method. The method is based on the LS-SVM (Least-Squares Support Vector Machines) theory. The paper describes the experimental approach and the simulation methods. Results of simulations retrieved from the classical method and the new inversion approach are compared.