Figure 4. High-resolution imaging results of three metallic objects, in which a horn antenna is used to emit a short pulse, and the other horn antenna is used for receiving the time-dependent scattered fields at a fixed location.

(a–c) Three metallic objects with increasing complexity, in which the distance between the objects and metasurface is set to be 0.3 m. (d–f) The imaging results using the traditional minimum least-square algorithm. (g–i) The imaging results using the iteratively reweighting algorithm. The imaging results demonstrate acceptable reconstructions of original objects, in which the use of advanced algorithm can further improve the imaging quality.