The requirement for a diffuse field in nonlinear imaging is integral to the performance of the technique, if the statistical conditions are not met by either taking a signal early in time or too late in time, the image performance will be degraded. Metrics to define the level of diffusivity such as phase coherence and standard deviation of energy are investigated to determine their suitability to define a diffuse state. These are compared against SNR in a nonlinear image to confirm they accurately determine a suitable gate time. In addition, the effect of gate length on the characterization of a diffuse field is investigated to determine an optimum duration. Together these provide a set of tools to determine the best parameters for nonlinear array imaging.
How to Cite:
Robinson, B. D. & Croxford, A. J. & Drinkwater, B. W., (2019) “Optimsation of gate time parameters for diffuse field nonlinear array imaging”, Review of Progress in Quantitative Nondestructive Evaluation .