Unmanned aerial vehicle (UAV) is an aircraft without a human pilot onboard. In a similar fashion as with autonomous cars or unmanned ground vehicles, depending on the level of autonomy (discussed later) the whole systems might use ground control station and vehicle operators that takes control over the system when necessary. The control system that enables UAV flying in autonomous mode is called – autopilot ^[1]. According to open sources (https://en.wikipedia.org/wiki/Unmanned_aerial_vehicle) UAV systems according to their functionality and applications are classified using the following groups:

• Target and decoy – providing ground and aerial gunnery a target that simulates an enemy aircraft or missile. This one of the first applications used even in the Cold wartime
• Reconnaissance – providing battlefield intelligence and ground data
• Combat – providing attack capability for high-risk missions
• Logistics – delivering cargo over the air, which usually is safer or faster than ground deliveries
• Research and development – improve UAV technologies
• Civil and commercial UAVs – agriculture, aerial photography, data collection

To understand significant differences and challenges addressed by each of the UAVs group, they have to be looked closer.

Flying target and decoy targets are among the first applications of unmanned aerial vehicles and historically goes back the Cold wartime when the first self-guided missiles were developed. For obvious reasons, the test targets had to mimic real target signatures, in every sense of this word, including shape, speed, manoeuvrability, electromagnetic reflection signature, thermal track of exhaust and other important features. These requirements and diversity of potential targets have facilitated the development of even higher diversity of UAV-targets and decoys – from small size low flying propeller aircraft to full-scale high-speed jet propulsion systems.

In military intelligence applications, the most valuable features are decreased visibility and extended remote sensing capabilities. However, not always it is possible to hit both targets. Therefore, most of the modern armies have intelligence drones of different sizes and flight schemas. For shorter ranges multi-copters that are specific with short flight time (~ 40 min.) and short-range remote sensor systems. For longer operation times fixed-wing aircraft are used like the one built by UAV Factory (https://uavfactory.com/en), which is a true market leader in the given segment – small fixed-wing drones. Fixed-wing aircraft can provide higher payload capabilities and higher energy-efficiency due to exploitation of aerodynamic forces. Currently, 24h flight time is rather widely available for this class of systems.

Combat UAVs are currently available in modern armies like the US as a solid part of conventional weapon systems. The impact on modern warfare is rather heavy changing not only tactics (regarding of richer intelligence available) but also strategies enabling to “fool” anti-air weapon systems and sometimes acting like a swarm of flying weapons. Some regional conflicts during the last decade show that combat UAVs might play the major role to take control over the battlefield. For instance, Turkish Byraktars in Lybia ^[2]. If for a moment we ignore ethical and humanitarian consequences of using combat UAVs in masses, those machines are of extreme effectiveness like cavalry a few centuries ago.

Using drones in logistics as a paradigm is not new, but still is not there. The most significant challenge is traffic control since the UAV systems will become a part of the air traffic and therefore both will bring new threats and opportunities at the same time. One can notice an obvious necessity for automatic traffic control systems instead of current human-operator based ones, which are of limited capacities and do no scale well. Some recent proposals have been made by NASA scientists ^[3]: