Add beamforming technique

[romulogcerqueira]

The current simulator can be extended to simulate other types of high-frequency sonars, such as multibeam profiling ones. To achieve that purpose, the simulator should incorporate the beamforming technique, a spatial filter that emphasizes and attenuates signals coming from different directions, after the noise simulation step.

This way, the simulator could also support the development of 3D structure inspection and bathymetry applications.