Root map characterization of interference location in a wide aperture antenna array

The utility of the root map (RM), commonly used for two-dimensional filter stability tests, as applied to the weights of an adaptive rectilinear antenna array to estimate interference direction-of-arrival is demonstrated. Contrary to the adaptive pattern, the cancellation pattern root map is shown to possess separate properties which allow accurate location of a single interference. One advantage of the RM method is that it requires fewer sample points than scanning-based algorithms, yet realizes superior resolution. Another advantage is that the RM method remains highly robust with both low SNR and with steering vector (pointing) errors