Cut-views of the 3D numerical model with the exterior shape corresponding to that of the asteroid 25143 Itokawa (Fujiwara et al. 2006). The signal paths between the transmitter (Tx) and the receiver (Rx) are also shown in various cut-views through the model. The real part of the exact relative permittivity distribution for the DM is piecewise constant with the values ε_r = 1, ε_r = 2.56 + j0.02, and ε_r = 3.4 + j0.04 inside the ellipsoidal internal void, in the mantle layer, and elsewhere within the asteroid body, respectively.