Estimation of instantaneous sound intensity field using a dense microphone array

Acoustic intensity estimation is an important research topic in the field of architectural acoustics. Various point-based intensity estimation methods using microphone probes have been proposed so far. On the other hand, research has also been conducted on average acoustic intensity field estimation methods using microphone arrays. This study proposes a method for estimating instantaneous sound intensity fields that can be applied to arbitrary spatial dimensions and array configurations. The proposed method is based on representing the instantaneous sound field using the reproducing kernel of a space of spherically band-limited functions. One of the key advantages of the proposed is its ability to analytically handle the spatial differentiation involved in the calculation of particle velocities, allowing for more accurate intensity estimation compared to the p-p method. Numerical simulations were conducted to validate the effectiveness of the proposed method, using a three-dimensional plane wave sound field.