Sea clutter suppression and micromotion marine target detection via radon-linear canonical ambiguity function

The micro-Doppler (m-D) signature of a marine target is used for detection within sea clutter in this study. The marine target usually has translational and rotational motions, and the corresponding radar returns can be modelled as a quadratic frequency modulated signal over a period of time. To compensate the range walk and Doppler migration of the micromotion target simultaneously, a novel long-time coherent integration detection algorithm, that is, Radon-linear canonical ambiguity function (RLCAF), is proposed. It has been proved that the m-D signal can be well matched and accumulated in the RLCAF domain using the long-time instantaneous autocorrelation function and associated with the parameterisation of the linear canonical transform. Furthermore, to suppress sea clutter and improve signal-to-clutter ratio, the authors propose a RLCAF spectrum subtraction method using the different properties of RLCAF representations between the target and sea clutter. Finally, experiments with real radar dataset indicate that the proposed method can achieve better integration and detection performance of a marine target with micromotion in case of high sea state.