Fixed Wing or Miltirotor for Survery or Mapping?

PROS AND CONS OF FIXED WING UAV

Unmanned aerial vehicles (also known as drones or RPAS) come in a range of shapes and sizes. All drones have individual characteristics and pros and cons. It is these characteristics which determine which platform is best suited to any individual task. It is crucial to understand these attributes to get the desired results you require from your mapping projects.

Pictured the Fixed wing Sensefly Ebee

FIXED WING OR MULTI ROTOR UAV FOR MAPPING

UAV, RPAS or drones come in two very different types, fixed wing and multirotor. Both have major advantages and disadvantages.

FIXED WING

Fixed wing UAVs consist of a rigid wing. Air within the earths atmosphere behaves like a fluid and it is this interaction between the aerofoil (wing) and the fluid which creates lift. Essentially this is because the wing generates lift as a result of moving through the air. Fixed wing UAV can create a force acting downwards which induces an equal and opposite reaction pushing the wing upwards. The wing turns a mass of air downwards creating a force, the equal and opposite reaction forces the aircraft upwards. Turn enough air and we can keep the weight of the wing in the air. Essentially this is because the wing on the aircraft generates lift as a result of moving through the air.

Fixed wing are a more economical way of flight than their multi rotor counterparts. This results in increased flight times for the same battery capacity. Another huge advantage fixed wing RPAS have over multi rotors is the simple structure ensures more efficient aerodynamics that provide the huge advantage of longer flight times at higher speeds allowing for larger areas to be surveyed.

A major disadvantage of fixed wing UAVs is they must be in motion to have air passing over the wing ensuring lift, meaning they must maintain constant forward motion. This means they do not offer the stationary characteristics offered by multirotors so sought after for inspections or oblique imagery.

MULTIROTOR UAVS OR DRONES

Multirotor aircraft use the rotors to create lift and also to manoeuvre. As we are using power to oppose the weight of the aircraft endurance is significantly reduced as compared with a fixed wing. However what they lack in endurance and battery life they make up for in agility and being able to get in and out tight manoeuvring situations. They also have the ability to hover in a stationary position something a fixed wing can not do.

A rotor is a rotating aerofoil designed to turn the airflow downwards to create lift.

Multirotor Drone – Hover UAV

The biggest advantage of rotory UAVs is the ability for takeoff and land vertically (VTOL). This allows the user to operate with in a smaller vicinity with no substantial landing/take off area required. Their capacity to hover and perform agile manoeuvring makes multirotor UAVs well suited to applications like inspections where precision manoeuvring and the ability to maintain a visual on a single target for extended periods of time is required.

Multirotors due to their lower speeds and shorter flight ranges will require many additional flights to survey any significant areas. The project will increase in time and operational costs if mapping and surveying large areas.