Aeroacoustic wideband array processing for detection and tracking of ground vehicles

Wideband array processing using a steered covariance matrix (STCM) [H. Wang and M. Kaveh, IEEE Trans. ASSP 33, 823–831 (1985)] was implemented and evaluated with experimental data from a small baseline aeroacoustic sensor array. The nonstationary character of acoustic signatures from maneuvering vehicles requires harmonic association and adaptive selection of an operating‐frequency set for the STCM on a data‐block by block basis. The sensor outputs are processed so that all selected frequencies with the same direction of arrival (DOA) have the same rank‐one representation in the steered covariance matrix. This matrix was used in the steered minimum variance (STMV) method [J. Krolik, in Advances in Spectrum Analysis and Array Processing, Vol. II, Chap. 6 (Prentice‐Hall, Englewood Cliffs, NJ, 1991)] to accomplish adaptive direction finding. Processing gain and corresponding improvement of accuracy in the DOA estimates was observed when compared to narrow‐band subspace methods such as ESPRIT. The STMV DOA es...