Performance of an adaptive array under sensor failure

It has been reported that during experiments with linear arrays at sea, sensor failure occurs with nearly 100% probability. An upper bound on the increase in sidelobe level for a nonadaptive weighted array with inoperative elements has been reported. The authors consider the performance of a narrowband adaptive array that has failed sensors. Assuming that each sensor fails independently and with equal probability, expressions for the expected signal-interference-to-noise (SINR) and variance are given. The mean minus three sigma is then used as the lower bound of the SINR under sensor failure. Simulation results verify the analysis for the expected SINR and show that the lower bound holds in 98% of the cases