On the problem of reconstruction of defects of complex shapes

The paper considers reconstruction of a defect of an arbitrary shape in a solid on the basis of changes in the characteristics of a back-scattered ultrasonic wave. Typical dimensions of the defect are assumed to be larger than the wavelength, and the defect is assumed to be in the far-field zone, which allows us to operate in the plane-wave approximation. An algorithm for constructing a convex shell for a non-convex defect using the return time of the back-scattered wave measured by scanning the angles around the tested object is described. The method is illustrated on examples of convex shells of two-dimensional defects of different shapes.