Direct path interference suppression algorithm of bistatic sonar system based on spatial smoothing

In the system of bistatic sonar, the direct path interference (DPI) can´t be suppressed in the time and frequency fields because the DPI is highly correlated with the target signals. A suppression algorithm based on adaptive spatial smoothing is put forward in the spatial field. In the case of uniform linear array, this algorithm first establishes the model of adaptive beam former to get the optimal weighted vector, then applies the vector to spatial smoothing beam form. Thus the correlativity between DPI and target signal is eliminated quite well to ensure the effect of DPI suppression. The results of simulation and experiments show that the algorithm is more effective than common spatial smoothing beam form algorithms to eliminate DPI.