Polarisation oblique projection for radar seeker tracking in chaff centroid jamming environment without prior knowledge

Chaff centroid jamming makes the indicated angle of a target by a radar seeker bias off the target, which is catastrophic to the radar seeker target tracking. In this study, the authors propose to suppress the chaff centroid jamming by polarisation oblique projection without prior knowledge of the target and the jamming polarisation parameters. At first, they prove that interference-to-signal ratio and in-phase monopulse ratio error after polarisation oblique projection are both independent of the estimation errors of the target polarisation parameters by theoretical derivation and geometrical interpretation. Then they estimate the polarisation parameters of chaff centroid jamming directly by the radar seeker received signal, and construct the polarisation oblique projection operator using the estimated jamming polarisation parameters and randomly set target polarisation parameters. They suppress the chaff centroid jamming with the estimated polarisation oblique projection operator, and demonstrate the validity of the proposed method by Monte Carlo simulations.