Sense and Avoid in UAS: Research and Applications

1

Introduction

George Limnaios,* Nikos Tsourveloudis* and Kimon P. Valavanis†

*Technical University of Crete, Chania, Greece

†University of Denver, USA

1.1 UAV versus UAS

An unmanned aerial vehicle (UAV), also known as a drone, refers to a pilotless aircraft, a flying machine without an onboard human pilot or passengers. As such, ‘unmanned’ implies the total absence of a human who directs and actively pilots the aircraft. Control functions for unmanned aircraft may be either onboard or off-board (remote control). That is why the terms remotely operated aircraft (ROA) and remotely piloted vehicle (RPV) are in common use as well [1]. The term UAV has been used for several years to describe unmanned aerial systems. Various definitions have been proposed for this term, like [2]:

A reusable1 aircraft designed to operate without an onboard pilot. It does not carry passengers and can be either remotely piloted or pre-programmed to fly autonomously.

Recently, the most reputable international organizations – like the International Civil Aviation Organization (ICAO), EUROCONTROL, the European Aviation Safety Agency (EASA), the Federal Aviation Administration (FAA) – as well as the US Department of Defense (DoD), adopted unmanned aircraft system (UAS) as the correct official term. The changes in acronym are caused by the following aspects:

• The term ‘unmanned’ refers to the absence of an onboard pilot.
• The term ‘aircraft’ signifies that it is an aircraft and as such properties like airworthiness ...