Figure 5.

Active cloaking of the electric self-potential ${\mathbf{u}}_d^{\square }$ on $\mathbf{\Gamma }$ (a) generated by the current source density ${\mathbf{f}}^{\square }$. Using Eq. (13) the cloaking devise is modelled by the current source density ${\mathbf{f}}_{c,\alpha }^{\square }$ (b) that generates ${\mathbf{u}}_{d,c}^{\square }$ (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 ${\mathbf{u}}_d^{\square }+{\mathbf{u}}_{d,c}^{\square }$ (see dashed line) on line ${\mathbf{\Gamma }}_1$ $\{\mathbf{x}\in {\mathrm{\Omega }}^a:x_1=0\text{km};x_3=0.5\text{km}\}\subset \mathbf{\Gamma }$.