Clutter Modeling And Clutter Suppression Technique Of Airborne Conformal Array Radar

Airborne conformal array radar is the development direction of the new generation of airborne radar.Compared with the traditional airborne array radar,it increases the stealth capability,survivability and the detection zone of the radar.When the radar is searching and tracking,it would be affected by the ground-scattered clutter signals.It is vital whether the radar can effectively deal with the ground clutter for improving the performance of radar.Usually,there are two ways to suppress clutter: reducing the side lobes of the antenna pattern and using Space Time Adaptive Signal Processing(STAP)algorithm.Due to the constraints of the antenna manufacturing and technology,the former has also been limited for suppressing clutter.In this work,the clutter modeling and clutter suppression of airborne conformal array radar is studied.And it analyzes the model of reflected signal and the way of clutter modeling of airborne conformal array radar.It discusses the factors affecting the clutter spectrum and the problem of increasing the clutter freedom of the conformal array radar.The nonstationary clutter of conformal array is analyzed and the effectiveness of the compensation algorithm is verified.On the basis of this,the conventional radar signal processing and STAP are used to suppressing clutter and performance of several classical STAP methods are evaluated by simulation.The details of this thesis are as follows:1.The second chapter interprets the way for constructing steering vector,the reflected signal model and clutter modeling method of airborne conformal array radar.Starting from the signal transmitted by the radar,the model of the reflected signal is derived gradually.Integration of equidistant ring surface scattering elements is used to establish the clutter model.The clutter spectrum in ideal conditions is showed.2.The third chapter studies spectrum,rank and nonstationary clutter.The work gives the factors affecting clutter spectrum and shows clutter spectrum in non-ideal conditions by simulation.The difference between the rank of conformal array and that of uniform array are studied.It also discusses the problem of increased clutter freedom.It studies nonstationary clutter.Due to nonstationary clutter,Doppler Compensation(DC),AngleDoppler Compensation(ADC)and improved ADC algorithms are introduced and the effectiveness of improved ADC algorithm is verified by simulation.3.The fourth chapter gives the radar detection capability and the process of signal processing.This work compares the performance of several clutter suppression methods.The detection range and detection capability of the conformal array radar are estimated theoretically.Ordinary radar signals processing,the basic theory of STAP,mDT,JDL,STMB and the selected clutter ridge algorithm are introduced.The improvement of clutter suppression performance by the direction optimization method is compared.And the clutter suppression performance of the above signal processing algorithm are compared by simulation.