Experimental Evaluation of Opportunity to Improve the Resolution of the Acoustic Maps

The work is devoted to the generation of acoustic maps. The experimental work considers the possibility to increase the resolution of the maps. The work uses two-dimensional microphone array with randomly spaced elements to generate acoustic maps of sources located in its near-field region. In this region, the wavefront is not flat and phase of input signals depends on the direction of arrival and the range as well. The input signals are partially distorted by indoor multipath propagation and related interference of sources emissions. For acoustic mapping with the improved resolution, an algorithm in the frequency domain is proposed. The algorithm is based on the modified method of Capon. Acoustic maps of point-like noise sources are generated. The maps are compared with the maps generated using other standard methods including built-in equipment software. The resolution improvement is up to 2.7 times. The obtained results are valuable in the estimation of the direction of arrival for Noise Exposure Monitoring.