Closed-Form Direction Finding Using Collocated but Orthogonally Oriented Higher Order Acoustic Sensors

This paper introduces new closed-form formulas to estimate an incident source's azimuth-elevation angle-of-arrival, for various combinations of higher order directional acoustic sensors, that are orthogonally oriented in a collocated triad. Also identified are the validity regions for un ambiguous estimation of the azimuth-elevation arrival-angle. These new direction-finding formulas may be used in the open literature's eigen-structure-based direction-finding algorithms, originally designed for (first-order) acoustic particle-velocity sensors.