US Patent 7355626 Location of events in a three dimensional space under surveillance

A surveillance system using an array of detectors onto which energy from the scene under surveillance is focused can indicate the direction of an event that has been recognized. The invention uses two or more arrays to locate events in three dimensions, and to define regions within the three dimensional space being surveyed. The events are located by detecting which elements from the respective arrays are stimulated by the occurrence of an event, and determining the location of the event to be at the intersection of the fields of view of the stimulated elements.