Research And Realization Of Passive Radar Signal Fusion And Sorting Technology

Passive radar multi beam reconnaissance technology has many advantages,such as large dynamic range,long operation distance,multiple narrow beams can realize monopulse direction finding,easy to realize the integration of active and passive,but there are also many problems:firstly,the beam changes from wide beam to multiple overlapped narrow beams to receive signals,multiple beams will respond at the same time,and the signal with strong side lobe energy is considered as the main lobe The received signal,as well as the transition band,cross channel and rabbit ear effect in the process of channelization,will cause the pulse signal redundancy,which will cause adverse effects on signal sorting.Secondly,the electromagnetic environment is more and more complex,and the traditional five parameters of signal sorting will appear unstable and chaotic.In order to solve the problem of redundancy and interference pulse in PDW caused by multi beam array antenna receiving signals at the same time,strong signal in non antenna reconnaissance direction and channelization technology,a PDW preprocessing method is proposed.It combines time domain,frequency domain and spatial domain to fuse the pulse sequence,which includes two parts: combining time domain and spatial domain,the side lobe blanking operation and spatial domain fusion operation are carried out to fully eliminate the redundant pulse generated by non antenna reconnaissance direction interference signal and multi beam response;combining time domain and frequency domain,the frequency domain fusion operation is carried out to fully eliminate the redundant pulse generated in the channelization process Redundancy and interference pulse of the system.The experimental results show that the redundancy and interference pulse in PDW sequence can be effectively eliminated by PDW preprocessing.Combined with the actual needs of the project,this paper proposes the dynamic PRI range estimation.According to the actual system,it proposes the time segmentation to reduce the adverse impact of too large interval between two pulses caused by intermittent acquisition on PRI accuracy.It realizes the multi-DSP pipeline,multi-core parallel radar signal sorting architecture based on TMS320C6678.Using master-slave parallel processing mode,and notify for inter core communication,the master sorting is applied to multi-core.The test results show that compared with single core operation,this method can effectively reduce the running time.In the complex environment,LPI radar gain is not high,which easily leads to inaccurate parameter extraction and parameter confusion.Aiming at the problem that traditional radar signal sorting relies too much on five parameters and needs to accumulate a certain amount of pulses to achieve signal sorting,this paper proposes a signal sorting method based on pulse pressure characteristics.This method makes full use of the received sampling data,considers the relatively stable intra pulse information,and synthesizes the inter pulse parameters to complete the signal sorting.The matched filter is constructed by using the time-domain sampling data of the pulse,and the remaining pulse is compressed.Then the CA-CFAR algorithm is used to detect the pulse compression results,so as to realize the signal sorting.Considering the computational complexity and real-time performance of signal sorting,and the traditional signal sorting method,the algorithm can be applied to the sorting of residual pulse after traditional signal sorting.Experiments show that this method can effectively separate LFM and BPSK signals.