Brian G. Ferguson
Defence Sci. and Technol. Organisation, P. O. Box 44, Pyrmont, Australia 2009
A passive broadband acoustic technique is described that detects the transit of a subsonic jet aircraft. The outputs from a pair of spatially separated microphones are cross-correlated in three overlapping frequency bands. The time lag that corresponds to the maximum value of the cross-correlogram is extracted for each of the three bands every second. Coincidence detection of this time lag information results in the detection of the jet transit with a negligible false alarm rate. The detection range is extended by applying the technique to the beamformed outputs from a pair of microphone arrays. The results of applying the technique to real data from 25 jet transits are presented.