Abstract：The shipborne high frequency sky-surface wave radar is a further extension of the sky-surface wave radar system under the traditional fixed platform.However,due to the influence of the shipborne platform motion and the ionosphere in the propagation channel,the first-order sea clutter spectrum exhibits more features.Based on the first-order electric field equation in the Walsh model,the analytic expression of the first-order ocean surface cross-section for the sky-ship propagation mode is derived.Then,according to the expression,the effects of different factors on the first-order spectrum are simulated and analyzed.Simulation results demonstrate that the radar operating frequency,the motion of the platform and the horizontal motion of the ionosphere are the main reasons of the first-order sea clutter Doppler spectrum broadening.The wind direction mainly affects the morphological changes of the first-order sea clutter spectrum,and this feature provides the possibility of ocean remote sensing according to the first-order sea clutter spectrum.
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2019, Vol. 47 
