SPP 1798, Subproject: Dynamic measurement of sound fields using compressed sensing

The objective of the proposed research is to explore the possibilities of measuring sound fields (plenacoustic functions) with moving microphones by making use of the theory of compressed sensing and to develop the corresponding tools. At first, a single omnidirectional microphone is considered for which the spatial location is assumed to be known during the entire measurement with respect to the initial position. This can be achieved in practice by either moving the microphone in a controlled way (e.g., by a robot arm) or by carrying out random movement by some other means and observing the microphone position with a fast tracking device. By exploiting the position information within a compressed-sensing based measurement, the proposed approach has the potential to capture the sound fields within a given volume by using only a hand-held microphone that is quasi randomly moved. A number of advantages is expected over methods that capture sound fields with large arrays of spatially distributed microphones. For example, with one microphone, no exact microphone calibration is needed. The practical applications are manifold, from listening-room-compensation over optimum loudspeaker placement to architectural acoustics, where reliable sound-field measurements could be obtained with a minimum of equipment. The second phase of the project will be directed toward optimizing spatial adaptivity and providing solutions for the multichannel case with several simultaneously active sources, including the use of moving microphone arrays.