[1] GIBs may be used in conjunction with an active underwater device (such as a pinger equipped torpedo), or with a passive acoustic sound source (such as an inert bomb striking the surface of the water).
Typically the sound source or impact event is tracked or localized using a time of arrival (TOA) technique.
Early GIBs were created for broad ocean area weapons testing by modifying conventional Navy sonobuoys with small OEM-grade GPS receivers and deploying them from a helicopter or from P-3 Orion aircraft.
Weapon strikes within the array emitted acoustic signatures that were captured by the GIBs and transmitted up to the orbiting aircraft.
Inert weapon releases from military aircraft strike the surface of the water within the array, emitting an acoustic signature that is captured by each of the GIBs.