Signal Model of a Rotating Microphone Array and Insights Into Its Spatial Response

This paper addresses the beamforming problem with a rotating microphone array, specifically a conical array mounted on a drone platform. Compared to traditional beamforming methods, developing and analyzing the associated beamformer is challenging due to the time-varying positions of the sensors. To tackle this issue, we introduce a coordinate system centered on the look position and define an averaged beampattern to assess the attenuation of noise from specific directions. Our findings reveal that the averaged beampattern is symmetric around the look position, which contrasts sharply with traditional microphone arrays that have fixed sensor positions. Finally, simulations illustrate this intriguing phenomenon alongside results from traditional arrays. These new observations and insights can aid in designing improved sound acquisition systems with rotating microphone arrays.