Self-rotation angle estimation of circular microphone array based on sound field interpolation

In this paper, we present a novel method for estimating the rotation angle of a circular microphone array (CMA) when multiple sound sources do not move but the CMA rotates instantly. We assume that the multichannel observation of the CMA at the reference position follows the multidimensional complex-valued Gaussian and model it. We utilize our previous research results on the interpolation of the sound field on the circle's circumference. Then, using the spatial modeling and sound field interpolation, we estimate the rotation angle of the CMA by the maximum likelihood method. We conducted numerical simulations that indicated the estimation accuracy of our proposed method to be within approximately five degrees and the algorithm to be feasible online.