**4.2 UAS swarm simulation in MCNP computed radiation field**

A realistic gamma-ray flux distributions in a 3D volume with dimensions of 100 m × 100 m × 32 m that contained five photon sources with energy ranging from 3 to 6 MeV were computed using MCNP. A concrete building was used in the model to introduce a structure that attenuates and blocks radiation flux in certain areas of the volume monitored by onboard sensors of UAS. Therefore, complex gamma ray flux distributions were generated (**Figure 15**).

The reference contour along with performance of the contour mapping algorithm overlaid onto this radiation field is shown in **Figure 16**. A two dimensional radiation distribution at the height of 15 m was used in this simulation (the UAS platforms were moving in the same plane). In this simulation, the swarm's starting position was located inside the radiation field at a point with coordinates (35 m; 35 m). The algorithm allowed mapping the desired contour with a reasonable accuracy.
