## 3 Results and Discussion
### Prallelepiped with Appendices  
Three configurations were considered. The first, object in a vertical position; the second, object in a horizontal position and rotating around the vertical axis; the third, sample in a precession, according to a 45\({}^{\circ}\) cone with respect to the vertical axis. In this configuration, an anticlockwise rotation was considered, with 0\({}^{\circ}\), 45\({}^{\circ}\), 90\({}^{\circ}\), 135\({}^{\circ}\), 270\({}^{\circ}\), and 315\({}^{\circ}\) positions. The positioning of the sample and the measures graphs are shown in Figures 9 and 10, respectively. Figure 8: Parallelepiped reflection trend. Figure 9: Parallelepiped with appendices positioning in respect to the wave incidence direction. (**a**) Horizontal and vertical positions; (**b**) precession positions. The case with the highest reflection is the horizontal position, with an increasing trend between 13 and 23 dB of reflection at the extreme frequencies. Vertical, vertical at 45\({}^{\circ}\) of rotation on the longitudinal axis, and horizontal at 45\({}^{\circ}\) of rotation on the longitudinal axis measures have a more flattened trend starting from 13 dB at 12 GHz and ending at 10 dB at 18 GHz. It is also important to note that several spikes on the plots are visible for all the positions at the same frequencies (16.5 GHz, 16.7 GHz, 17 GHz, 17.4 GHz, 17.8 GHz). All the precession positions are visible at 18 GHz, except position Precession 3. From 15.5 GHz to 18 GHz, satellites in Precession 0 and Precession 2 are always visible, while objects in the Precession 1 position are visible between 17.3 and 18 GHz only. At lower frequencies, from 12 to 13.8 GHz, satellites in the Precession 2 position are not visible, while Precession 0 and 1 present the highest values of reflection. The test campaign leads to the consideration that scaled objects, in horizontal, vertical, vertical at 45\({}^{\circ}\) of rotation on the longitudinal axis, and horizontal at 45\({}^{\circ}\) of rotation on the longitudinal axis positions, with the dimensions range aforementioned, are visible with a 400 MHz radar system. That means that, for instance, an object of 3.46 m at 17.8 GHz, with relative appendices, is clearly visible. For precession positions, an object of 3.5 m length is always visible, except when in the Precession 3 position and its attitude is determined by its reflection value. Objects between 3 and 3.5 m are visible when in Precession 0 and Precession 2 positions, while when in the Precession 1 position, only objects between 3.4 and 3.5 m are visible. Objects from 2.4 to 2.7 m in the Precession 2 position are not visible, while Precession 0 and 1 present the highest reflection. As a concluding remark, in view of the differences in the above-mentioned reflected values, the different attitude positions can be clearly found for the objects under consideration when they are tracked with a 400 MHz radar signal. Regarding the 18 GHz frequency (3.5 m scaled object), the reflection signal related to the relative attitude positions is highlighted in Figure 11, where both planar and precession positions are shown. Figure 10: Parallelepiped with appendices signal reflection: TE polarization reflection vs. frequency. The great visibility of the object can be noted when it is placed in horizontal positions and rotation; instead, when in precession, it appears clear that the visibility depends on the relative position but, thanks to the presence of the appendices, only the 315\({}^{\circ}\)--Precession 3 position is not visible. The reflection trend for the in-plane positions leads to the consideration that, because the larger is the width of the body exposed to the EM field, the higher is the reflection and thus the visibility, the presence of the appendices enhances the reflection properties of the body in horizontal 0\({}^{\circ}\) position.