An apparatus and method for inspecting a structure are provided which
include receiving probes and area transducers disposed proximate opposite
surfaces of a structure under inspection. An area transducer uniformly
emits ultrasonic signals over an area which may be scanned by a receiving
probe without corresponding movement of the area transducer. An area
transducer may be moved over the surface of the structure or repositioned
to provide additional inspection area for the receiving probe to scan,
including to provide for continuous inspection. Multiple area transducers
may be used in sequence to provide for continuous inspection. Multiple
receiving probes may be used, independently or collectively as an array,
to increase inspection of a structure, taking advantage of the large area
of ultrasonic signals emitted by one or more area transducers.