Using the sphericity test for source detection with narrow-band passive arrays

A new sphericity test statistic is proposed for the complex case with a distribution that approaches the asymptotic chi-squared distribution much faster than previously proposed statistics, especially for situations in which the sources are very difficult to detect, such as closely spaced or weak sources. Consequently, the probability of a correct estimate is superior to those resulting from other sphericity tests. The capability of this new sphericity test to detect closely space sources is examined and compared to the resolution capabilities of bearing estimation algorithms as well as other well-known source detection algorithms