A Broadband—Holography Imaging System for Nondestructive Evaluation
Acoustical Holography has become a powerful means in computerized non-destructive testing. To obtain a good axial resolution the conventional monofrequent concept /1/ was extended to Multifrequency Holography /2/. Here the data-acquisition has to be repeated several times using a series of different frequencies. A further step is to excite the system with broadband signals, to obtain the object information over a certain range of frequencies within a single measurement procedure. This leads to the principle of “Broadband Holography”, a reconstruction scheme, which is similar to. the well known LSAFT algorithm /3/.
KeywordsInverse Filter Object Area Transmitted Waveform Acoustical Holography Finite Impulse Response Digital Filter
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