Zephyr: A High Altitude Long Endurance Unmanned Air Vehicle ...

Chapter 1Introduction and BackgroundA HALE UAV is a high altitude long endurance unmanned air vehicle. As the namesuggests, it can fly at an altitude of over 30,000 feet, for as long and as far as thepower supply allows it. A UAV can either be controlled by a remote control, have apre-programmed auto pilot system, or use a telecommand system from a groundstation.There are many UAVs available, ranging from micro UAVs that are a few centimetreswide to large UAVs that are comparable in size to passenger planes, with their usesand applications ranging from precision bombing to monitoring hurricanes. There aretwo main categories that UAVs of all sizes fit into; those used in warfare and those forcommercial and civil applications. UAVs that are used in warfare are most commonlyfor reconnaissance (i.e. gaining battlefield information), combat (capable of droppingbombs and other weapons) and target and decoy (the opposition attack these thinkingthey are carrying the enemy, enabling the actual enemy to attack unsuspectingly). Thecivil and commercial applications have a much larger scope. The most commonapplications are for surveillance (i.e. monitoring an area for suspicious behaviour),remote sensing (taking images of the ground for mapping or environmentalmonitoring for example), communication, and scientific research (for example flyinginto a hurricane). UAVs are very useful as they can perform jobs that would be toorisky for a human to do, or that are simple, monotonous and long.To date, most UAVs use internal combustion or jet engines and are directly controlledvia remote control from the ground (as aforementioned). This means that not only will1