Anti-jamming Approach Of Anti-ship Missile Using Inertial Navigation System Information

Radar seeker is the main sensor of most Anti-ship Missiles(ASM) in terminal guidance, and its performance has a direct impact on ASM performance. It is difficult for traditional radar seeker to adapt to the complex electromagnetic environment of modern battlefields. Accordingly, it is urgent to research on anti-jamming techniques of radar seeker under confrontation condition and improve the adaptability of radar seeker to electromagnetic environment in modern battlefield.If the radar seeker is jammed, the precision of ASM would decrease. The thesis proposed an anti-jamming method based on Inertial Navigation System(INS) information to improve the performance of ASM. It consists of three parts, which is the pattern of ASM electromagnetic jammers, analysis of INS error and the anti-jamming method based on INS information.Based on the operating characteristics of ASM, the second chapter divided jamming into three patterns: outboard passive jamming, outboard active bait and ship-borne active interference. And it analyzed the principle and tactical operation in detail. The above analysis provides theoretical basis for anti-jamming measures of radar seekers and scenario settings of simulation.When INS information is used in target tracking of ASM, the navigation error affects the tracking accuracy of the missiles. Therefore, the third chapter is based on the principle of the INS, and analyzed the mechanic configuration of north-pointing INS platform, derives the mathematical model and analyzes the error characteristics of INS by simulation.According to the scenarios of jammed ASM radar seekers, two anti-jamming methods are proposed in chapter 4. One solved the chaff centroid jamming based on INS information. The other is proposed for noise suppressing jamming based on INS information. According to the scenario of chaff centroid jamming, the first anti-jamming method made use of both INS information and radar seeker information. The model of anti-jamming simulation is then established and simulation was conducted to verify the effectiveness of this anti-jamming method. It also simulated the affects of the following factors on hitting probability: the position accuracy of INS, target ship maneuvering, the distance between missile and ship when false target is released, the proportional navigation ratio, the SNR of reflected waves, and so on. The second method is proposed for noise suppressing jamming , which is based on the INS information. Simulation model is established accordingly, and the effects of this anti-jamming method is analyzed. Simulation results show that this method is able to anti jamming when the distance between the missile and the target is small, but when the distance of missile-to-target is large, target ship maneuvering restrict the implementation of this anti-jamming method.