@inproceedings{viator99b, author = {J. A. Viator and S. A. Prahl}, title = {Photoacoustic Imaging of Gelatin Phantoms Using Matched Field Processing}, booktitle = {SPIE Proceedings of Laser-Tissue Interaction X}, year = {1999}, editor = {S. L. Jacques and G. J. M{\"u}ller and A. Roggan and D. H. Sliney}, pages = {276--283}, volume = {3601}, abstract = {Matched Field Processing (MFP) has been used in the ocean acoustics community to localize acoustic sources by correlating experimental data with a modelled field based on a solution to the acoustic wave equation. Here we attempt to adapt the method of MFP to localize an acoustic source in a tissue phantom made from an acrylamide gel. An acrylamide gel in a cylindrical geometry was formed with a small optically absorbing sphere embedded within it. A Q-switched, frequency- doubled Nd:YAG laser operating at 532\,nm coupled to an optical parametric oscillator (OPO) tuned to 726\,nm was used to irradiate the absorbing sphere. The pulse duration was 4.75\,ns and the absorption coefficient of the absorbing sphere was 15\,cm$^{-1}$. The stress confined laser energy resulted in an acoustic pulse radiating from the absorbing sphere. A piezoelectric transducer was used to detect the pulses at various locations on the gel. By vertically translating the transducer a virtual hydrophone array was constructed. The acoustic field was modeled using normal mode methods. A simulation was performed using the normal mode model as virtual data which was then correlated with the normal mode model itself. Finally, the experimental acoustic array data was correlated to the normal mode model.}, }