Coordinated Target Detection And Tracking Of Frequency-phase Hybrid Array Radar

Different from Phased Array(PA),Frequency Diverse Array(FDA)are capable of detecting distance information by adding frequency offset between arrays.The additional range dimension of freedom makes the FDA have a good application potential in range parameter detection and range dependent clutter suppression.In this thesis,the concept of frequency diversity is deeply studied on the basis of FDA.PA and FDA are combined in different dimensions,and the two parts of data are co-processed,so that different arrays such as spatial frequency-phase hybrid array and time-domain frequency-phase hybrid array are generated.Algorithms are proposed in the aspects of low complexity super-resolution target parameter estimation,low small slow feature target detection and low small slow target adaptive tracking.The research content and main innovations of this thesis are as follows:(1)Low-complexity super-resolution target parameter estimation method for spatial frequency-phase hybrid array: The array is divided into PA and FDA part by frequency offset division.The Angle estimation of the PA part is used to decouple the Angle range of the FDA,so that the dimension of two-dimensional spectrum estimation is reduced to two steps of one-dimensional estimation.In addition,the optimal Angle weighting value is derived based on the linear minimum mean square error criterion,and the optimal results are given by co-processing the estimation information of the two-part array.The cramér rao lower bound of frequency-phase hybrid array is derived and the performance advantage of frequency-phase hybrid array and optimal angle estimation is shown.(2)Low-small-slow target detection with time-domain frequency-phase hybrid array:Aiming at the detection problem of moving targets with low-small-slow characteristics,such as unmanned aerial vehicle(UAV)and floating balloon under the urban background,the time-domain frequency-phase hybrid array is formed by adding frequency offset between different pulses of the PA.Based on this frequency-phase hybrid array,a Doppler compensation target detection algorithm is proposed.Based on the range-Doppler coupling characteristics of the array,the clutter is moved out of the target element by doppler compensation to achieve clutter suppression.This algorithm can make full use of the doppler shift brought by the motion of the target in the complex strong clutter environment to complete the detection of the target.(3)Adaptive moving target tracking with subarray frequency-phase hybrid array: In view of the difficulty of detecting low,small and slow characteristic targets,frequency bias is added between the phased subarray and pulses to form a space-time frequency-phase hybrid array with subarray distribution.On the basis of this array,an adaptive transmitting parameter optimization target tracking algorithm based on extended Kalman filter is proposed.Combined with the idea of cognitive radar,the transmitting beam weight vector is updated according to the real-time data snapshot in the tracking process,so as to achieve the matching beam irradiation of the target.The simulation results show that the tracking error of this method is lower than that of orthogonal or additive weighted emission.With higher accuracy.