Patent ID: 8624605

Claim:
A method to determine a unique waveform fingerprint of an object having an enclosed space, comprising the steps of: (a) injecting a waveform having a first frequency into the enclosed space of the object, wherein a wavelength of the first frequency of the waveform is smaller than a characteristic dimension of the enclosure such that a plurality of resonant modes are simultaneously excited; (b) collecting the waveform amplitude and phase as a function of time after it has been reflected from or scattered by physical features or structures in the enclosed space of the object; (c) incrementally step increasing the frequency of the injected waveform and injecting it into the object over a predetermined range of frequencies; (d) collecting each waveform amplitude and phase as a function of time after it has been reflected from or scattered by physical features or structures in the enclosed space of the object over the predetermined range of frequencies; and (e) generating a waveform fingerprint of the object from a plurality of collected waveforms, wherein the waveform fingerprint is a composite frequency, time, amplitude and phase representation that characterizes the interior configuration or physical features or structures in the enclosed space of the object.