Patent ID: 8120994
Filing Date: 2012-02-21
Classification: G01S,G06F

Abstract:
1. An apparatus comprising a receiver comprising: a base having a planar base surface; first and second acoustical sensors that detect an acoustical signal emitted by a moveable signal source, said first and second acoustical sensors being mounted on said base and separated from one another; a first EM detector that detects a first EM signal that is synchronized with said acoustical signal; and a controller that measures the difference in time of detection between said first EM signal and said acoustical signals detected by said first and second acoustical sensors; wherein said first and second acoustical sensors each comprise: a detector that generates an electrical signal in response to an acoustical signal in a predetermined frequency range; a housing surrounding said detector, said housing having an aperture defined by an axis, wherein said acoustical sensor has a reception function that is symmetrical about said axis, said axis being substantially perpendicular to said base surface.