Total least square clutter cancellation in passive radar

Abstract

In this study, a total least square (TLS) based cancellation method is proposed for suppressing direct and multipath clutter signals in passive radar. The TLS algorithm is first used to estimate the distribution of the clutter signals over delay bins. Then the clutter signal subspace is constructed by delaying the reference signal according to the estimated number and delay bins of the clutter signals. Finally, the surveillance signal is projected into the orthogonal subspace of the clutter space. Compared to the typical extended cancellation algorithm, the proposed method uses a smaller but more accurate order of clutter space, so it can get accurate estimate of the clutter amplitudes by only using a limited length of signals. This indicates the proposed method is with the potential to suppress time-variant interference where only a small number of signal samples is available.