Research On Radar Jamming Countermeasures Based On Polarization

Modern warfare involves a more complicated electronic environment,and methods for radar jamming and anti-jamming are developing all the time.Active interference is becoming a prevalent form of radar jamming,which makes it challenging to remove disturbances to radar in the air,time,and frequency domains.This is due to the maturation of digital radio frequency memory(DRFM)technology.In the case of active interference,new anti-interference processing methods,such as polarization domain signal processing,are required.Polarization radar is a new type of institutional radar that identifies target signals and suppresses interference signals by taking advantage of the difference in polarization between targets and interference.This thesis aims to solve the problem of reducing the interference problem of polarimetric MIMO radar under the condition of active interference,and the specific methods are studied,and the anti-jamming ability of MIMO radar is strengthened to a certain extent by using game theory and polarimetric diversity technology.This study provides new ideas and methods for the application of polarimetric radar in the field of anti-jamming.The main work content is summarized as follows:1.The anti-interference technology based on polarization filtering is studied.First,polarization definition,methods for characterizing polarization,and polarization descriptors are presented.The radar polarization measurement technique is then introduced,and the advantages and disadvantages of different polarimetric measurement systems are compared and summarized.Finally,the polarization filtering technology is introduced,and the effectiveness of the polarization filtering technology against interference is verified by simulation experiments.2.On the foundation of both real and fake target recognition,the anti-spoofing jamming method of polarimetric MIMO radar is investigated.Under the background of active interference,through the characteristics of polarized MIMO radar system,the true and false target recognition problem is simplified to a binary hypothesis test problem by using the characteristics of true and false targets in the polarization domain,and then the target detector is designed according to the likelihood ratio criterion to improve the true and false target recognition performance.To enhance the radar’s ability to reduce interference,the polarization of its transmitting and receiving terminals has been tuned.3.The anti-spoofing jamming technology of polarimetric MIMO radar based on game theory is studied.In the context of polarimetric MIMO radar,polarization diversity is adopted for the transmit array,and based on the concept and advantages of game theory,the polarization design problem of the radar system is described as a two-player zero-sum game(TPZS)between the radar and the jammer.In addition,two emitting polarization design methods are proposed for different situations: a one-sided game for non-intelligent jammers and a strategic game for intelligent jammers.The optimal strategy and Nash equilibrium solution in the two cases are given,so as to obtain the optimal emitter polarization of the radar system and improve the radar interference suppression performance.