Bistatic(Multistatic) Radar Coherent Processing

The stealth target and the low altitude,slow speed small target(LSS-Target)in the future put forward high requirements for radar detection power.Multi-radar coherent processing is an important development direction of radar signal processing,which can improve the performance of target detection and recognition with a strong environmental adaptability and a low-intercept and anti-jamming capability.The thesis focuses on the problem of target detection in low SNR,studies on coherent synthesis for multi-radar,coherent compensation for the range profiles,and longtime coherent integration for bistatic radar.The works and contributions are summarized as follows:(1)The coherent synthesis of narrow-band signals received by bistatic radar is investigated.The influence of noncoherent errors on the received signals are analyzed,the range profile is aligned by taking advantage of the strategy named as the target region reference distance matching preprocessing,a bistatic radar phase mismatch model is established,and the method of parameter estimation based on correlation is given.(2)The compensatory parameters estimation for multi-radar coherent synthesis is investigated.The amplitude and phase relationship between the received signals is established,a coherent parameter estimation method based on subspace decomposition combined with least squares estimation is proposed,which leads to the multi-radar signal reconstruction and coherent synthesis.(3)The coherent compensation method of bistatic radar range profile is investigated.The noncoherent model of bistatic radar range profiles is deduced,a high accuracy phase compensation method based on image criterion is proposed.(4)The weak target integration detection based on bistatic RFT is investigated.The long time coherent integration method of bistatic radar based on RFT is given,the algorithm integrates the straight lines determined by the target motion parameters meanwhile adds doppler filtering to achieve the target autofocusing detection.In order to solve the problem of blind speed side lobe(BSSL)in the practical application,the constraint conditions of BSSL nonoverlapping are derived,and a method of improved symmetric window is proposed for the BSSL suppression.