Time domain visualization using acoustic holography implemented by temporal and spatial complex envelope.

Spatial envelope was proposed to show the location of acoustic sources and overall radiation pattern by the authors [C.-S. Park and Y.-H. Kim, J. Acoust. Soc. Am. 125, 206-211 (2009)]. The envelope can provide sufficient information on where the sources are and how the energy propagates into space. This concept is certainly useful for time domain acoustic holography since one can utilize not only spatial envelope to envisage what one needs to know but also temporal envelope to reduce the number of data. A holographic process to obtain spatial envelope is therefore introduced and verified, and how much one can reduce the processing time by implementing envelopes is compared with the conventional holography.