Detection of chaff centroid jamming aided by GPS/INS

Chaff centroid jamming released by vessel makes the target indicated azimuth angle of radar seeker of anti-ship missile bias off the target. The failure to detect the presence of chaff centroid jamming is catastrophic to target tracking for the radar seeker. In this study, the authors take the azimuthal in-phase monopulse ratio of radar seeker as test statistic and detect the presence of chaff centroid jamming with the aid of GPS/INS. Probability density functions of the azimuthal in-phase monopulse ratio when jamming is absent and present are derived at first. Then the authors propose a method using the measured information of both GPS/INS and radar seeker to estimate the target off-boresight azimuth angle which is vital for detection threshold setting. Finally, the authors show the performance of the chaff centroid jamming detection by simulations and analyse the effects of some key jamming parameters on detection performance.