Wireless Propagation Characterization of Underground Sewers Towards Autonomous Inspections with Drones

In tunnel-like environments such as sewers, road tunnels and mines, a robot or team of networked mobile robots can provide monitoring services, surveillance or search and rescue. However, these scenarios pose multiple challenges from the robotics and from the communication points of view. Structurally, sewers are GPS-denied and narrow scenarios with lack of illumination and presence of sediments, and in the communication context, the multipath propagation causes strong fading phenomena. In this work we characterize a sewer scenario from the communications point of view, based on a measuring campaign carried out in the sewers of the city of Barcelona, Spain, in the context of an ECHORD++ project towards future inspection with drones.