Computer-aided analysis of interferometric images of unsteady aerodynamic flows

An algorithm was developed for computer-aided analysis of interferometric fringe patterns which relate to the instantaneous pressure coefficient fields of unsteady aerodynamic flows. Fringe centerlines are extracted by locating intensity extrema in the image. Edge detection using a dual threshold is employed as a guide for approximately locating the extrema and data smoothing via Chebyshev polynomial approximation is used to unambiguously locate the extrema. Quantitative pressure coefficient distributions result from the procedure.