Adaptive wideband aeroacoustic array processing

Incoherent and coherent wideband array processing techniques for aeroacoustic detection and tracking of ground vehicles are contrasted. Experimental results for a circular array are presented, illustrating complexity and performance tradeoffs. Incoherent and coherent MUSIC are used for comparison. Complexity is dominated in both cases by singular value decomposition (SVD) calculation performed M times for the incoherent case and S times for the coherent case, where M is the number of frequency bins and S is the number of look angles. Good results are obtained with the incoherent method for small M provided adequate narrowband SNR is available. The coherent approach is more statistically stable, and S can be reduced by employing a priori coarse direction estimates