Reconstruction of smooth shape defects in waveguides using locally resonant frequencies

This article aims to present a new method reconstruct slowly varying width defects in 2D waveguides using locally resonant frequencies. At these frequencies, modes propagate the waveguide under form of Airy functions depending on parameter called point. In this particular point, local is known and its location can be recovered from boundary measurements wavefield. Using same process for different we produce good approximation all waveguide. Given multi-frequency taken at surface waveguide, provide L \infty-stable explicit We finally validate our numerical data, discuss applications limits.