# Anti-Collision System for Small Civil Aircraft
## 5 Conclusions  
The main contribution of this paper is that we derived algorithms for the operation of an anti-collision system for small civil aircraft, and also designed movement trajectory models of five flying objects which operate within the aviation communication network. Movement trajectories of the FOs were modeled in a geocentric coordinate system. Based on the acquired algorithms and models of FO trajectories, a simulation of the operation of an anti-collision system for small civil aircraft was carried out. During the simulation, it was assumed that flying objects RJA39K, FHM6112, LOT653, WZZ3007, and LOT5 MF operate in the communication network of aviation. The LOT5 MF is a small civil aircraft equipped with an onboard anti-collision system. Using the anti-collision system, it establishes its position based on the data received from the aforementioned flying objects. The Matlab software was used to carry out the computer simulation. The accuracy of determining the position of a flying object LOT5 MF with an anti-collision system depending on the errors of the position data of flying objects RJA39K, FHM6112, LOT653, WZZ3007 was investigated. The errors of the coordinates of the flying objects were simulated by the constant k, the value of which was modified from 0 (no error) up to 3 (maximum error). The simulation results prove that the precision of position identified by the anti-collision system in the model simulation presented in Figure 7, with the constant k ranging from 0.1 to 3.0,  
Figure 10: Accuracy of ACS positioning for selected positions FOs, straight flight. varied (dispersions \(\sigma^{2}_{\Delta\text{P}}\) of ACS positioning errors) from 1.94 m\({}^{2}\) to 503.23 m\({}^{2}\). During the flight with the maneuver, the positioning error of the anti-collision system was greater. See Figure 8. Based on the acquired simulation results relating to the presented model situations, it can be concluded that it is possible to apply the anti-collision system designed onboard small civil aircraft. The accuracy of positioning by the anti-collision system onboard LOT5 MF depending on the mutual positions of flying objects RJA39K, FHM6112, LOT653, WZZ3007 was verified using the simulation. Deriving from the simulation results presented in Figure 10 can be stated that the anti-collision system identified its position with the errors depending on its distance from individual FOs. Modifying the distance between the anti-collision system and individual FOs from 10.0 km to 50.0 km, the errors of position identification were ranging from (dispersions \(\sigma^{2}_{\Delta\text{P}}\) of ACS positioning errors) 4.29 m\({}^{2}\) to 68.25 m\({}^{2}\). This fact confirms that the designed anti-collision system is operational in establishing its position against other FOs, with the distance from the given FOs being 50.0 km maximum. This can be explained by the fact that the anti-collision system's position is established by a distance-measuring method. The advantage of the anti-collision system is that it is independent of satnav systems and secondary radars. The disadvantage of the proposed anti-collision system is that it identifies its position only with those flying objects that are part of the air communication network. On the other hand, the essential advantage of this system is its low price. As stated in [23], the average root-mean-square error (RMSE) proposed by the system ADS-B (Automatic Dependent Surveillance-Broadcast)/MLAT (Multilateration Surveillance) data fusion framework is 15.3 m compared to the average RMSE of ADS-B which is 30 m. ADS-B is directly dependent on GNSS (Global Navigation Satellite System). Based on this, we can say that the accuracy of the anti-collision system is better. Conceptualization, M.D. and P.D. ; data curation, M.D. ; methodology, L.M., formal analysis, P.D. and L.M. ; validation M.D. and P.D. ; supervision, L.M. and P.D. ; resources, M.D. and P.D. ; writing--original draft preparation, M.D. and P.D. ; writing--review and editing, L.M.