Two-dimensional noise source imaging with a T-shaped microphone cross array

Spatial cross-correlation beamsteering with a T-shaped sparse array can provide an efficient procedure to identify the directions and to obtain the emission levels of multiple uncorrelated noise sources. The procedure can be applied to stationary or moving sources. It provides two-dimensional image resolution equivalent to that of a full array, but requires significantly fewer microphones. This results in substantially reduced requirements for data acquisition and signal processing, with a material cost reduction. Simulation, laboratory measurement, and field measurement of a train moving at high speed illustrate application of the procedure.