Figure 4.

Active cloaking of the electric potential ${\mathbf{u}}_d^{+}$ on $\mathbf{\Gamma }$ (a) generated by the current source density ${\mathbf{f}}^{+}$. Using Eq. (13) the cloaking devise is modelled by the current source density ${\mathbf{f}}_{c,\alpha }^{+}$ (b) that generates ${\mathbf{u}}_{d,c}^{+}$ (c) leading to a significant reduction (almost cancellation) of the electric potential signal on $\mathbf{\Gamma }$ (d). Panel (e) demonstrates the cancellation of the signal ${\mathbf{u}}_d^{+}+{\mathbf{u}}_{d,c}^{+}$ (see dashed line) on the middle path (line ${\mathbf{\Gamma }}_1$: $\{\mathbf{x}\in {\mathrm{\Omega }}^u:x_1=0\text{km};x_3=0.5\text{km}\}\subset \mathbf{\Gamma }$) of the synthetic measurement data.