Research On Simulation Technique Of Ground And Sea Clutter

The radar clutter reflected from the ground or sea is called ground clutter or sea clutter. For most radars, the clutter is unuseful and the existence of it seriously affectes the performance of the radar and contributes a serious disturbance to the normal work of the radar. In order to enhance the radar ability, it is necessary to dig into the characteristics of the clutter and establish the accurtate clutter model. Through the study of the simulatiing method,it can not only provide more realistic clutter environmental model for the simulation of the radar system,but also help to design and realize the radar clutter filter.And also,it can enhance radar's suppression ability to the clutter and improve the performance of the radar. So modeling and simulation of ground and sea clutter plays an important part in the designment of radar simulator and has a very important practical significance.The article takes the ground and sea clutter as the study objects and then does some research. It studies the characteristics of ground and sea clutter, studies modeling and simulation methods for clutter and then does the experimentes,then generates the stochastic sequence with special probability density function and special power spectrum distribution. The contents of the research mainly include the following several aspects:(1) The paper introduces the characteristics of ground and sea clutter. It studies and analyzes the Radar Cross-section, the divisiory method for the clutter units and the scattering characteristics of ground and sea clutter. For the scattering characteristics of ground and sea clutter, the article proposes the corresponding calculation-models for their backscattering coefficients. Then, according to the giving models, it simulates and gives the variation diagrams which are the values of backscattering coefficient changing with the grazing angle.(2) The paper introduces the probability distribute models and correlated models,and then sums up the application of various models. It also studies the modeling methods of clutter. On the process of modeling and simulation,for the designment of filter,the article proposed to use a modified LEVINSON recursive algorithm to compute the filter coefficient of AR model and gives the analysis.(3) For the various of distribution models,the paper studies the steps of using ZMNL method to model and simulate the clutter,and then gives the simulation. The results shows that, the simulation results can be largely fit with the theoretical results. The simulation has a certain practical value in the project.(4) In the simulation of Weibull distribution clutter,for ZMNL method, because the formulas which describe the relation between the correlation coefficients before and after the nonlinear transform is difficult to be solved with visualized method,so the article proposes a kind of method based on the iterative algorithm to simulate the Weibull distribution clutter.The article gives the simulating results,and then compares with the theoretical results. From the obtained simulation results,we can conclude that the simulation method can be better meet the amplitude distribution and spectrum power distribution requirements.It shows that the improved method is effective and feasible.