Reconstructing the shape of an object from its mirror image

An image of an object can be achieved by sending multiple waves toward it and recording the reflections. In order to achieve a complete reconstruction it is usually necessary to send and receive waves from every possible direction [360° for two-dimensional (2D) imaging]. In practice this is often not possible and imaging must be performed with a limited view, which degrades the reconstruction. A proposed solution is to use a strongly scattering planar interface as a mirror to “look behind” the object. The mirror provides additional views that result in an improved reconstruction. We describe this technique and how it is implemented in the context of 2D acoustic imaging. The effect of the mirror on imaging is demonstrated by means of numerical examples that are also used to study the effects of noise. This technique could be used with many imaging methods and wave types, including microwaves, ultrasound, sonar, and seismic waves.