Target detection based on time reversal with polarisation array antennas

Abstract

Polarisation diversity radar enhances the performance of target detection. Time reversal exploits the multipath effect by adaptively matching propagation channels to improve the signal-to-noise ratio (SNR) and realise high detectability. This work combines polarisation diversity and time-reversal technology to propose a time-reversal detector suitable for a polarisation array radar. The maximum likelihood estimate is carried out for the time-varying channel response to solve the channel mismatch problem, which may cause the degradation of time-reversal performance. In addition, a conventional polarisation detector is developed under the same varying channel scenario to benchmark the time-reversal detector, and furthermore, the SNR gain of the time-reversal detector over the conventional detector is derived. Numerical simulations demonstrate the superiority of the time-reversal detector. Both the polarisation detectors proposed can take advantage of the channel variations to improve the detectability, and the greater the energy brought by the channel changes, the better the detection performance achieved.