Research On Sub-aperture Imaging Algorithm And Anti-interference Of Missile-borne SAR

Synthetic Aperture Radar(SAR)is an important radar technology research direction in modern times.It can perform long-distance and high-resolution imaging of the scene target in any weather condition and time period,thus replacing traditional optical and infrared remote sensing in military radar applications.SAR has become a military radar system with more research and application value.The missile-borne synthetic aperture radar is one of the important applications of SAR in the military field.Among many imaging algorithms,the sub-aperture imaging algorithm has the advantages of excellent imaging effect,strong real-time performance and easy motion compensation.Therefore,the algorithm is more suitable for missile-borne SAR system.In this paper,the sub-aperture imaging algorithm and anti-interference technology of missile-borne SAR are studied.The main contents are as follows:1)Two kinds of sub-aperture imaging algorithms for missile-borne SAR are studied.Firstly,with the combination of imaging principle of synthetic aperture radar and the geometry model of the stripe mode,detailed theoretic deduction of the improved RD algorithm based on azimuth sub-aperture and the improved OSA algorithm based on pulse compression are conducted respectively.Theoretical derivation,and the high real-time performance of the two algorithms are analyzed through the storage and calculation of the data processing module.Finally,two imaging algorithms are simulated via Matlab.The results verify the correctness and effectiveness of the two algorithms.2)A method of time-delayed transmission interference of missile-borne SAR is introduced.According to the principle of active deception interference and the geometric model of time-delayed transmission,algorithm flow of distance-to-delay aimed interference,azimuth-delayed-delay and distance-azimuth joint-delay aimed interference are deduced.With the combination of the interference algorithm flow and the above two sub-aperture imaging algorithms,the three interference methods are stimulated.The results verify the correctness and effectiveness of the three delay transponders.3)The anti-delayed transponder interference method of missile-borne SAR is studied.According to the principle of delayed transponder interference,the differences between the real target echo signal and the false target echo signal are analyzed.In addition,theoretical derivation of random primary phase anti-interference,frequency-adaptive polarity agility anti-interference,and random primary phase and frequency-aggressive polar aggression joint anti-interference are conducted respectively.Finally,with the combination of the above three methods for time-delayed forwarding interference.The three anti-delayed repeater methods are simulated and the results verify the correctness and effectiveness of the three anti-interference algorithms.In the end,the main research contents of this paper are summarized and the aspects that need to be improved in this paper and the direction of further research are stated.