This paper reviews applications of wideband frequency modulation techniques to acoustic microscopy. The similarities and differences between chirped systems in which the waveform is recompressed with a matched filter and those in which non-linear mixing is used are discussed. Many of the considerations which determine the performance of the systems are presented.
M G Somekh,
"A Discussion Of Wideband Frequency Modulation Techniques For Acoustic Microscopy", Proc. SPIE 0809, Scanning Imaging Technology, (3 August 1987); doi: 10.1117/12.941515; https://doi.org/10.1117/12.941515