Research On Simulation Technology And Description Method Of Non-stationary Sea Clutter

When the sea surface is detected by the radar,the echo signal obtained by the radar is disturbed by the sea clutter with the deeply influence of the background.Therefore,Deeper researching on the sea clutter signal is important for reducing the effect of sea clutter.In this paper,the sea clutter signal is studied in detail from the aspects of modeling method and statistical method.The sea clutter can be effectively generated in the case of measured data and no measured data,which has certain practical meaning for the study of sea clutter.This paper studies the sea clutter by two aspects,then we generates the non-stationary sea clutter signals of some classical distribution model with Wen's Spectrum,and verifies the non-stationary characteristics of the generated sea clutter signal.The first method generates sea clutter signals by simulating a three-dimensional modeling.This method generate sea clutter signals by simulating the actual physical scene,including generating dynamic sea surface by linear filtering method,calculating the echo signal by physical optics method and multi-layer fast multipole algorithm.The quasi-static method is used to obtain the time series signal.Then the sea clutter signal in each case were analyzed and summarized;the second method generate sea clutter signal by the use of statistical modeling method.This paper uses ZMNL and SIRP to generate six distribution,Which includes not only four kinds of distribution models,such as Rayleigh distribution,which are suitable for conventional narrowband radar,but also include distributed models such as generalized compound distributions for wideband radar sea clutter simulation,in which this paper introduces the variation of the radar sea clutter signal with the changes of resolution and distance.Then we study the estimation of the parameters of the sea clutter model,which includes the shape parameters and the power parameters of the generalized compound distribution model and the generalized K-distribution model under the condition of measured sea clutter data and no measured sea clutter data.The studies of GC-PDF and GK-PDF show that the generalized complex distribution and the generalized K distribution are degraded into several other distribution models with specific parameter,and the widely use of these two distributions.Optimize the method of generating the sea clutter of GC-PDF and GK-PDF with considering the physical feasibility of the filter,the influence of thenonlinear transformation on the spectral broadening and the phase correlation of the clutter signal.This improvement has a certain value.Finally,the AR model method is used to generate the complex K-distributed sea clutter signal using the venturi spectrum,and the amplitude difference distribution of the obtained sea clutter is fitted by Tsallis distribution.It is proved that the sea clutter signal With non-stationary.