Vendetta Final Proposal Part 1 (3.4 MB) - Cal Poly

shows, most threats will be from below and at shallow angles of about 15° while at 50,000 ft during ingress. Because ofthis, the 0° and 15° lookup angles were analyzed. The results of the Radbase2 software are illustrated first in Foldout 3.which depicts the radar cross-section of the aircraft from a frontal, or 0° lookup angle.The figure shows that the vehicle does clearly meet the frontal RCS requirement of 0.05 m 2 (-13 dBm 2 ) set forthin the RFP. It also shows that the iterative measures taken to shape the aircraft worked. The leading edge and trailingedge of the wing come together closely. There is a large return directly from the side of the aircraft due to the wingtipand fuselage side. It can also be seen that, although there are slight variations in the returns due to the differentfrequencies, they do not vary much due to the fact that the Vendetta is a rather large vehicle; hence none of the surfacesare small enough to interfere at the radar wavelengths. The weakest azimuth angle for the Vendetta is the 40° anglewhere the leading edge sends a large spike forward. However, the Vendetta meets the RFP requirement for a full 77° ofazimuth.Looking at the equally crucial 15° lookup angle cross-section in Foldout 3 reveals a slightly different picture. Itshows that the Vendetta meets and exceeds the 0° lookup angle returns. This is highly advantageous. The shape of thebottom of the aircraft is effective in keeping spikes at a minimum. As mentioned earlier, this is a crucial area for theVendetta. As most of its threats are from the ground, it is important that the aircraft has a limited return in thisorientation.The threat chart shows that the Vendetta would remain in range of the Soviet SA-12 and SA-6 SAMs for 160seconds and 60 seconds, respectively. This means that the returns from the bottom of the Vendetta are crucial for threatassessment. The software was used to generate an RCS butterfly plot in a sweep around the vehicle to determine thefootprint that it will leave as it flies above its threats. Foldout 3 shows this sweep.It can be seen that the 60° facets on the bottom of the fuselage are deflecting radar away from the vulnerablelookup orientation. The aircraft is still producing a large return of almost +40 dBm 2 in this position, however. Onceagain, there is little variation in the returns for various frequencies. Mission planning would become crucial to be surethe Vendetta avoids flying directly over only these long-range, high flying threats such as the SA-12.It is important to note that the addition of radar absorbing material (RAM) would further reduce some of thereturns on the aircraft. Note that all plots shown reflect the fact that software is assuming fully reflective metal on allsurfaces. No cavities are being modeled besides the inlets. This is a conservative approach. RAM could be applied inactuality to reduce some of the returns on the bottom and front of the aircraft.15