Self-Localization of Single Microphone from Ultrasound Field Generated by Sources with Subwavelength Displacement

We propose a self-localization method of a single microphone based on measured phase gradient of wave field created by sources with sub-wavelength movements. Unlike most of conventional localization methods based on time-of-arrival (TOA) of time-difference-of-arrival (TDOA) from impulsive wave packets emitted from sources, we employ spatial information of wave field that is entirely derived from the wave equation containing a point source. Instead of impulsive emissions, continuous sinusoidal wave from a point source is utilized in our technique. We describe a localization strategy that integrates multiple measurements for a stable and robust performance. We verified the validity of our method via numerical and realenvironment experiments.