Study On The Cooperative Anti-jamming Techniques For Radar/Infrared Compound Seeker

The multi-mode compound guidance has already become the development direction of modern seeker. The combination of the precise range data measured by the radar sensor and the angle data by the infrared sensor can greatly improve the guidance precision of the seeker. Besides, the infrared imaging sensor outperforms the point-source sensor in terms of target recognition ability. Moreover, radar and infrared spectrum are far apart from each other, which makes it difficult to interfere them simultaneously. Therefore, radar/infrared imaging composite guidance has become the first choice for the anti-ship missile. With regard to the possible interference in the tracking process of anti-ship missile, a fusion algorithm of radar and infrared imaging data is proposed to achieve the purpose of cooperative anti-jamming.Firstly, the interference faced with the radar/infrared seeker of anti-ship missile is analyzed in terms of the interference principle and implementation methods. Secondly, based on the study of the information fusion technique of radar/infrared seeker, the category, workflow, and algorithm of information fusion method are discussed respectively. Then a feature-level distributed fusion scheme is designed. A optimal information fusion algorithm is obtain through simulation experiment, in which a modified K near neighbor path correlation method is used for track association, while the covariance weighted fusion algorithm for track fusion. Finally, a cooperative anti-jamming algorithm for radar/infrared imaging composite seeker is proposed. After track correlation, the target state residual information is used to detect the interference, and the local track quality to estimate the disturbed sensor. To counter the disturbances in the tracking process, the local tracks of radar and infrared sensors are re-established, re-associated and then fused.Simulation experiments in MATLAB verify the anti-jamming algorithm. The effectiveness of this algorithm is validated by adding the infrared surface source and active electromagnetic interference at different tracking moments of the composite seeker. The radar and infrared observation points are used in the fusion center to form the respective local tracks with the extended Kalman filtering(EKF) algorithm. The simulation results show that the interference can be detected promptly after track correlation. By comparing the radar and infrared track quality, the disturbed sensor can be accurately determined. By isolating the disturbed sensor and re-establishing its local track, the track association and track fusion are performed to achieve the purpose of cooperative anti-jamming. Simulation results reveal that the algorithm can obtain a hit rate 95% or more in the interference background.Simulation and analysis validate the ability of the cooperative anti-jamming technique to resist kinds of possible electromagnetic and infrared interferences in the tracking process of anti-ship missile. With this technique, as long as the radar-infrared local track deviation exceeds the detection threshold of the interference, it can be determined that the composite seeker is disturbed. Therefore, the proposed method has the ability to resist a variety of electromagnetic and infrared interference.