The discrimination and recognition of underwater targets by an operating sonar array depends on its true structural dynamics. These dynamics are directly related to the mechanical and physical interfaces between transducers and their supporting and radiating structures. Such complex assemblies require sophisticated bonding and processing of compliant and rigid materials which determine the operational parameters of the sonar system. Understanding the effects of structural anomalies and defects is of critical importance to insuring correct array operation and a nondestructive method for the visualization of anomalous structural characteristics would be of great value in both development and testing of sonar systems. Knowledge of the mechanisms for acoustic energy transfer through the sonar structure into the water medium can be inferred from these visualizations and would enhance the analysis of returned signals for homing and target recognition in operation. Holographic interferometry has presented itself as a viable and useful method for the realization of this type of information.
Howard Fein, Howard Fein,
"Holographic analysis of the dynamics and structure of sonar transducer arrays", Proc. SPIE 2234, Automatic Object Recognition IV, (29 July 1994); doi: 10.1117/12.181017; https://doi.org/10.1117/12.181017