| The passive radar is a kind of radar that is more adaptable to battlefield changes and has strong survivability.It plays a very important role in reconnaissance.Compared with the traditional ground-air passive radar,the airborne passive radar with space-based radar as the radiation source can better meet the needs of modern warfare.However,under this system,the clutter distribution is complex and changeable,and the distance correlation is relatively strong.It is difficult to obtain sufficient training data.Space-Time Adaptive Processing(STAP)can effectively suppress clutter and detect targets,but it requires more training samples and a large amount of calculation;Parametric Adaptive Matched Filter(PAMF)algorithm can reduce the amount of calculation and sample requirements to a certain extent.In this paper,the research on reducing the calculation amount and training data requirements of the airborne passive radar clutter suppression and moving target detection algorithm is carried out.The main work is as follows:(1)Complete the geometric modeling of the airborne passive radar scene and conduct the analysis of the direct wave suppression technology based on the ECA-B algorithm;then simulate and analyze the characteristics of the clutter based on the four typical airborne external radiation source radar flight scenes;finally,two classic clutter suppression and target detection algorithms of STAP and PAMF are introduced,and the simulation results and detection performance of the two algorithms are analyzed.(2)Optimize the STAP and PAMF algorithms in the airborne passive radar scene from the perspective of increasing the degree of freedom of the airspace.Firstly,based on the relationship between the performance of the space-time signal processing algorithm and the degree of freedom,starting from the non-uniform array,the meaning of the two non-uniform arrays and their respective acquisition methods are introduced in detail,and then the STAP/PAMF algorithm based on the non-uniform array is proposed.Simulation of algorithms and analysis of deployment detection performance and calculation amount under the clutter scene of airborne passive radar.(3)Optimize the STAP and PAMF algorithms in the airborne passive radar scene from the perspective of increasing the degree of freedom in time domain.Firstly,simulate and analyze the clutter spectrum broadening characteristics of the airborne radar under different pulse repetition frequencies;then,by analogy with non-uniform arrays,the STAP algorithm based on non-uniform pulses is proposed,and combined with the PAMF structure,a non-uniform pulse-based algorithm is proposed.The PAMF algorithm of spatial whitening first and then temporal whitening;finally,the detection results and performance are analyzed in the clutter scene of the airborne external radiator radar.(4)Completed the FPGA implementation of the airborne passive radar clutter suppression and moving target detection system.Firstly,design and demonstrate the system and each implementation module according to the indicators,including the PAMF algorithm based on dimensionality reduction time-space whitening,digital beam forming(DBF)and moving target detection(MTD);then complete the implementation design of the above modules and programming,and then verify the feasibility of the system through functional simulation,sub-system joint debugging and overall joint test.Finally,the practicality and real-time performance of the system are verified through the processing of measured data. |
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