Chapter 8

UAV Remote Sensing in Precision Agriculture

(book excerpts)

Unmanned aerial vehicles (UAVs), commonly known as drones, are among the most successful technologies in precision agriculture and smart farming. In the past, remote sensing was often based on satellite images or images acquired by using manned aircraft in order to monitor vegetation status at specific growth stages and soil properties. However, satellite imagery is often not the best option because of the low spatial resolution of images acquired and the restrictions of the temporal resolutions, as satellites are not always available to capture the necessary images. In addition, long periods are often required to wait between the acquisition and reception of images. In addition, environmental conditions, such as clouds, often hinder their reliable use. Considering the use of manned aircrafts, usually it results in high costs, and many times it is not possible to carry out multiple flights to obtain more than a few crop images. The development of UAV-based remote sensing systems has taken remote sensing and precision agriculture (PA) one step further. The use of UAVs to monitor crops offers great possibilities for acquiring field data in an easy, fast, and cost-effective way compared to previous methods. UAVs’ ability to fly at a low altitude results in ultra-high spatial resolution images of the crops (i.e., a few centimeters). This significantly improves the performance of the monitoring systems. Furthermore, UAV-based monitoring systems have high temporal resolution as they can be used at the user’s will. This enhances the flexibility of the image acquisition process. In addition, UAVs are a lot simpler to use and also cheaper than manned aircraft. Moreover, they are more efficient than ground-based proximal systems as they can cover a large field in a short amount of time and in a non-destructive way, which is very important. With UAVs, the actual flight process is relatively straightforward. UAVs are controlled using software on a ground control device (typically, a tablet, laptop, or smartphone); the operator draws an outline of the area to be surveyed on a Google map type of view. The software programs the flight, overlaying lines on the map to show the drone’s flight path. The information is uploaded to the drone over a wireless link. Takeoff, flight, and landing are completely autonomous (manual override allows the operator to avoid unexpected objects in the flight path, such as a manned plane).

Click on the following topics for more information on UAV remote sensing in precision agriculture.

Topics Within This Chapter:

  • Advantages and Limitations of UAV Remote Sensing
  • Advantages of UAV Remote Sensing
  • Limitations of UAV Remote Sensing
  • UAV Platforms
  • Fixed-Wing UAVs
  • Advantages
  • Disadvantages
  • Rotary-Wing UAVs
  • Advantages
  • Disadvantages
  • Vertical Take-Off and Landing UAVs
  • Advantages
  • Disadvantages
  • Components of UAVs
  • Airframe
  • Power Source
  • Batteries
  • UAV Flight Controller
  • Core Functions of a Flight Controller
  • Software
  • UAV Navigation and Positioning System
  • GNSS Receiver
  • Ground Control Points
  • RTK/PPK Base Station
  • UAV Ground Control Stations
  • Core Functions of Ground Control Stations
  • UAV Communication Systems
  • UAV Protocols in Communication Systems
  • UAV Communication Links
  • Real-Time Data Transmission Software
  • UAV Payload (Mission-Specific Sensors or Tools)
  • UAV Sensors
  • UAV Spray Systems
  • UAV Failsafe and Safety Systems
  • Manual or Autonomous Control Methods of UAVs
  • Manual Control Methods
  • Autonomous Control Methods
  • UAV Mission Planning
  • UAV Image Acquisition Parameters
  • Selection of Sensors and Lenses
  • Flight Speed
  • Time of Day
  • Flight Altitude
  • Terrain Following
  • Image Overlap
  • Flight Direction
  • Viewing Angle
  • Waypoints
  • Flight Planning Apps
  • Core Functions of UAV Flight Planning Apps
  • Digital Image Processing and Analytics of Remote-Sensed Data
  • Digital Image Processing
  • Digital Image Analysis
  • Federal Aviation Administration’s Regulations for Drones
  • FAA Requirements for Flying a Drone
  • Drone Swarms for Farming
  • UAV Remote Sensing Applications in Precision Agriculture
  • UAV Weed Mapping and Management
  • Sensors
  • Machine Learning for Mapping Weeds
  • Crop Monitoring and Yield Estimation
  • Disease and Insect Surveillance
  • Machine Vision and Machine Learning for Detecting Insect Pests and Diseases
  • Phenotyping
  • Crop Spraying
  • UAVs Versus Aircraft Crop Spraying
  • Swath Testing
  • Label Restrictions