Figure 1

System composed of a 2D cluster of cylindrical scatterers randomly placed inside a cylinder or radius $R$ centered at position ${\mathbf{r}}_0$ where the source is lying in the forward problem (surrounded by an exclusion surface of radius $R_0$). Detection with a single point sensor lying at position ${\mathbf{r}}_d$ in the far field (a) or a closed cavity (TRM) (b). Real scatterers positions are displayed in (a) and (b).Reuse & Permissions

Figure 2

Normalized broadband time-reversed intensity ($\Delta /\Gamma =2$) as a function of space for (a) a single point antenna (the left figure is a section view of the right 3D plot) and for (b) a closed cavity. (c) Normalized monochromatic time-reversed intensity ($\Delta /\Gamma =0$) as a function of space for a single point antenna.Reuse & Permissions

Figure 3

Normalized monochromatic time-reversed intensity $I_{\mathrm{TR}}\left(\mathbf{r},\Omega +\delta \right)$. (a)–(c) correspond to the case of a system with a large optical thickness $b=2R/{\ell }_B\left(\Omega \right)=17.4$ [i.e., the system shown in Fig. 1a] for three different frequencies given by (a) $\delta /\Gamma =0$, (b) $\delta /\Gamma =0.5$, and (c) $\delta /\Gamma =1$. (d)–(f) correspond to the case of a system with an optical thickness close to unity $b=2R/{\ell }_B\left(\Omega \right)=2.1$ [i.e., a small section of the system shown in Fig. 1a] for the same three different frequencies [respectively, (d), (e), and (f)]. In all figures, the white dashed-dotted circle represents the boundary of the scattering cluster. The position of the single point antenna can be guessed in the top-right corner of the maps because of the presence of interferences fringes.Reuse & Permissions