What Are Drones?
Unmanned aerial vehicles (UAV), commonly named drones, are small aerial platforms weighing up to 20 kg (50 lbs). Due to their size, they cannot be boarded by a human body (yet). Drones can be operated in two ways; directly, in which a human has complete control of the vehicle by wireless remote; and autonomously, in which the vehicle is able to control itself and follow a route based on the data from GPS or other sensors.
There are many different kinds of unmanned aerial vehicles and can be categorized into the following groups:
- Fixed wing; very simple vehicle to control. It has some form of a non-movable wing and a propeller that facilitates forward movement. Due to its construction, it must always be moving relative to the air around it to stay aloft. Hence, it’s operation can be greatly affected by the wind. Another limiting factor is that larger drones require some kind of runway area that can be used for deployment and retrieval, while smaller ones can be hand launched and retrieved by landing on a soft surface.
- Rotary wing; the most common drone type. It looks like a small helicopter since it has multiple rotors (typically 4-8). Due to its rotary system, the drone has the ability to hover and can be vertically deployed and retrieved. The rotary wing vehicle has some advantages over the other types. It is small and easily transportable and less liable to mechanical failure. The main disadvantages, though, are its limitation in cargo it can carry, as well as its battery life, which is limited to allow only 15 minutes or less of flight.
- Tethered vehicle is a common drone tethered to a wire to eliminate the need for a remote controller. Drone movement is therefore confined according to the tether. Moreover, tethered drones have many different variations. They can range from a standard drone moved according to the tether to a drone tethered with a microfilament wire with an installed power system for unlimited flight.
- Lighter-than-air (LTA) vehicles include blimps and other typical helium-filled crafts tethered to some kind of wire. Their main disadvantages are the difficulty in transporting because of their size, and the fact that they cannot tolerate even moderate wind speeds. Therefore, LTA drones are used less in farming.
Crop Data Delivered from the Air with Unmanned Aerial Vehicle (UAV)
Drones are small and light aerial vehicles which may fly at extremely high altitudes and carry various navigation systems or recording devices such as RGB cameras, infrared cameras, and other sensors. Due to their ability to deploy various sensors and capture high-resolution and low-cost images of crop conditions, drones are very useful in farming.
Initially used for chemical spraying, today drones are a great tool for capturing aerial imagery with platform mounted cameras and sensors. Images can range from simple visible-light photographs to multi-spectral imagery that can be used to assess different aspects of plant health, weeds, and assets.
Drones collect raw data and translate it with algorithms into useful information. Therefore, they can be used for various applications in farming, such as the monitoring of the following parameters:
- Crop health; damage made by pests, color change due to pest infection
- Vegetation indices; leaf area, anomaly detection, treatment efficacy, phenology, yield
- Plant height; plant height and density
- Plant scouting; plant size, plot statistics, stand number, compromised plots, planter skips
- Water needs; water-stressed parts of the field/orchard in need of watering
- Soil analysis; nutrient availability for plant nutrient management
To summarize, drones help farmers optimize the use of inputs such as seeds, fertilizers, water, and pesticides more efficiently. This allows timely protection of crops from pests, saves time for crop scouting, reduces overall cost in farm production, and secures high yield and quality crops.