Tethered drones and Tether Ground Stations

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The use of unmanned aerial vehicles (UAV) at Emergency and Rescue operation sites is steadily increasing.

The advantages are obvious:

Comprehensive reconnaissance can be carried out quickly and the results are available in real time. A greater challenge, however, is the continuous and comprehensive control of the operational environment, especially in large-scale emergencies such as forest fires or floods. These emergencies often pose an acute threat to the population over a period of several days.

This is precisely where there is a technical gap in the continuity of monitoring damage situations. On the one hand, there are unmanned aerial vehicles, which have many advantages due to their low acquisition costs and high availability. On the other hand, there is a high logistical effort if the drones are to remain permanently in the air, for example to keep an eye on the spread of a fire front or the safety of dikes at critical locations, or to monitor filling stations for sandbags from the air. A continuous supply of full batteries must be ensured, although it should be noted that it is necessary to land every half hour for a battery change. The alternative is currently manned aviation, which also cannot remain in the air indefinitely, but has larger and often better sensor technology. The main disadvantage is the cost intensity of these missions.

A fairly recent possibility to close the gaps is the use of so-called tethered drones, colloquially also called cable drones. 

Tethered drone systems - Cablebound drones

Tethered drone systems offer a good expansion option for the UAV already used by fire departments, emergency and rescue forces, police and others. Tethered drones draw all their power permanently from the ground via a cable. Power is fed into a ground station (tethered ground station, short: TGS), where it is converted to suit the UAV. All that is required is to replace the drone's battery with a suitable on-board component. In the best case, such as with the Kite 75, this can be done completely without tools at the site of operation.

Advantages of Tethered drones

The UAVs used can nevertheless be used as free-flying UAVs, as already known. However, if a permanent overview of the situation from the air is required, this can be achieved in a few simple steps by switching to TGS operation, with a continuous power supply to the drone from the ground.

Another advantage of tethered drones are the data conductors in the supply cable. These data conductors can be used to feed sensor data from the drone into a mission network. They can even be used to control the UAV completely without radio components. Given the increase in radio applications, this can also reduce interference. The biggest advantage, however, is the high possible data transmission rate, as well as the option to process this data more effectively on the ground. 

The possible operational scenarios and thus also the operational tactical value of an entire drone unit increases enormously as a result. This is especially true if the local operational concepts are revised and thought through further, depending on the possible applications. For example, it is quite conceivable that a drone unit could even be deployed for diving missions. The UAV can be placed in the area close to the shore, or even on a boat, and support the divers from the air. Radio and LTE repeaters can be attached to the UAV to increase its range over the entire duration of the mission.