Measurement of Sound Fields Using Moving Microphones
This addresses the challenge of high spatial sampling requirements and calibration difficulties in acoustic measurements, offering a customizable trade-off between measurement effort and time.
The paper tackles the problem of efficiently sampling sound fields by using moving microphones with known trajectories, reducing the need for many fixed microphones and enabling reconstruction of the entire sound field through spatial interpolation.
The sampling of sound fields involves the measurement of spatially dependent room impulse responses, where the Nyquist-Shannon sampling theorem applies in both the temporal and spatial domain. Therefore, sampling inside a volume of interest requires a huge number of sampling points in space, which comes along with further difficulties such as exact microphone positioning and calibration of multiple microphones. In this paper, we present a method for measuring sound fields using moving microphones whose trajectories are known to the algorithm. At that, the number of microphones is customizable by trading measurement effort against sampling time. Through spatial interpolation of the dynamic measurements, a system of linear equations is set up which allows for the reconstruction of the entire sound field inside the volume of interest.