Detection of narrowband sources by an array

Adaptive array techniques which seek to optimise the passive detection of an acoustic narrowband source under ideal conditions are well established. The paper gives details of a frequency-domain technique which has modest hardware requirements and yet is capable of operation in a highly nonstationary environment. In addition, the algorithm enhances both signal/noise gain and detectability when mismatch occurs, particularly for the important case of low input signal/noise ratio. The suggested technique includes linear interpolation, and yet is shown to give near-optimal performance.