A technique for adaptive polarisation filtering in radars

The ratio of the average target-signal power to the average unwanted-signal power at the input of a radar detection receiver can be significantly increased by applying some methods of adaptive signal processing based on the exploitation of the polarization state of the radar return. The suppression of unwanted radar echoes is generally obtained by a vector processing of the dual-polarization radar signal which is equivalent to appropriately adapting the state of the receiving antenna to the unwanted environment. In this paper, after discussing some concepts of adaptive cancellation of partially polarized unwanted radar echoes, we analyze the operation and performance of a new non¬linear adaptive polarization canceller which can be used to improve the signal-to-disturbance ratio in the presence of barrage jamming or precipitation clutter. To this end, some results are also pres¬ented which pertain to experimental dual-polariza¬tion radar data.