Drone dictionary — essential terms every pilot should know

Whether you’re a seasoned UAV pilot or an aspiring operator looking to take to the skies, there is always something new to learn about piloting and operating drones. To help all you seasoned professionals and newcomers alike, Waypoint has collected a glossary of terms designed to help you brush up on your existing knowledge and maybe even learn something new.

The following are terms often used in relation to UAVs, UAV operation and the industries they operate in, specifically mining, construction and agriculture.

Above Elevation Data (AED): unique to AgEagle’s eMotion flight planning software, AED altitudes are relative to the currently active elevation data model and is defined as the altitude approximately above the ground.

Above Ground Level (AGL): the altitude of a drone’s flight height.

Above Mean Sea Level (AMSL): the altitude relative to a standard mean sea level geoid.

Above the Takeoff Altitude (ATO): the altitude relative to the place a drone started its motor just before takeoff.

Background Map: a visual 2D map of a region featuring landforms, roads, etc., onto which additional data is layered, also referred to as a base map.

Base Map: (see Background Map)

Beyond Visual Line of Sight (BVLOS): an operating method whereby an unmanned aircraft is flown beyond the visual line of sight of the operator.

Ceiling height: the maximum adjustable vertical height that the drone can fly to within the allowable working area.

Check Point: a surveyed point on the ground used to verify the accuracy of photogrammetric outputs. These includes DSMs, point clouds, 3D mesh, orthomosaics and DTMs.

Contour Map: a topographic map that delineates surface elevation using contour lines.

Drone: an unmanned aircraft that can navigate autonomously, without human control or beyond line of sight.

Digital Elevation Model (DEM): a 3D display in form of a raster grid that features the bare earth, removing all natural and artificial features.

Digital Surface Model (DSM): a 3D display of an area that includes the tops of buildings, trees and other ground-based objects.

Digital Terrain Model (DTM): a 3D display of vector data that features natural terrain and regularly spaced points.

Expanded Polypropylene (EPP): a highly versatile and shock-absorbent type of foam.

Extended Visual Line of Sight (EVLOS): an operating method in which the drone operator relies on remote observers to continuously keep the drone within visual line of sight.

Federal Aviation Administration (FAA): a branch of the department of transportation in a United States-based government organization that focuses on aviation regulations. The FAA is responsible for the United States and its surrounding international waters.

Flight Log: a record of a single flight. Traditionally, this would be written by a pilot. In the case of eBee drones, this is a digital record that is generated automatically.

Geotag: an electronic tag (grouping) of geographic information (coordinates) that is assigned to media such as photographs and videos via the process of geotagging. In the case of eBee drones, this process is handled automatically via the eMotion flight-planning software).

GeoTIFF: a public domain metadata standard that allows georeferencing information to be embedded within a TIFF image file.

Geographic Information System (GIS): a system that lets users visualise, question, analyse and interpret data to understand spatial relationships, patters and trends.

Global Navigation Satellite System (GNSS): a satellite navigation system with global coverage, such as GPS, GLONASS and the European Union’s Galileo system.

Globalnaya Navigazionnaya Sputnikovaya Sistema (GLONASS): refers to Russia’s version of GPS, another navigation system with global coverage and similar precision.

Global Positioning System (GPS): refers to the United States NAVSTAR Global Positioning System, a space-based navigation system that provides location and time information anywhere on or near the Earth.

Ground Control Point (GCP): a location or object on the ground that has precisely known coordinates. Used to improve the precision of DSMs created by photogrammetric analysis of a series of images.

Ground Control Station (GCS): a ground-based control center, such as a laptop computer, that allows for human control of UAV flights.

Ground Sampling Distance (GSD): the distance between two consecutive pixel centres measured on the ground, also referred to as ground resolution. A GSD of 5 cm means one pixel in the image represents 5 linear centimetres on the ground.

Ground Resolution: (see Ground Sampling Distance)

Image Overlap: an intersection of imagery. The more image overlap, the better the output. It helps the software process images and create a clearer, more detailed map.

Index Calculator:  a generated index map/grid where the color of each pixel is computed using a formula that combines different bands of the reflectance map.

Index Map: a map that represents specific values for vegetation or soil, such as greenness or soil moisture.

Inertial Measurement Unit: (IMU): an electronic device used to manoeuver aircraft, which detects changes in acceleration and rotation. Comprised of sensors such as accelerometers, gyroscopes and sometimes magnetometers.

Infrared imagery: the output of images based on heat energy of the infrared spectrum.

Keyhole Markup Language (KML): an XML notation for expressing geographic annotation and visualisation within internet-based, two-dimensional maps and three-dimensional Earth browsers.

Keypoint: an identifiable point in an image. The process of photogrammetry involves the matching of common keypoints on two or more images.

Kinetic Energy: the energy an object possesses due to its motion.

LiDAR: a remote-sensing technology that measures distances by illuminating a target laser and analysing the reflected light.

Light-emitting Diode (LED): a semiconductor device that emits light when an electric current is passed through it.

Magnetometer: a geophysical instrument that measures the strength of the Earth’s magnetic field. Used to alongside sensors such as gyrometers and accelerometers to determine an aircraft’s altitude (it’s orientation relative to the Earth’s horizon).

Meta Data/Metadata: a set of data that describes other data. In the case of a photo, metadata might include where an image was captured (i.e. its geographic coordinate), who captured it, the camera used and more.

Multispectral imagery: the output of images that measure wavelengths through light, which then comes together in multiple layers of wavelengths to create geographically accurate mosaics.

Normalized Difference Vegetation Index (NDVI): one of the most commonly used vegetation indices in precision agriculture. NDVI provides information regarding the chlorophyll content in plants.

Orthomosaic: a large image comprised of adjoining orthorectified images that have been digitally reconstructed. A common mapping drone output (often in GeoTIFF format).

Orthophoto: an aerial image where the effect of the central projection has been removed (orthorectified) according to the DTM and the orientation of the image. Refers to a single image from a satellite, aircraft or drone.

Parallax: the effect caused by an object’s apparent location viewed from two different lines of sight.

Payload: a component or product carried by a drone to fulfil a specific mission. In the case of aerial imaging drones, the payload is the camera.

Photogrammetry: the science of recording, measuring and interpreting photographs through data retrieved about physical objects and the environment.

Pitch: an aircraft’s rotation when the nose moves up or down about a transverse axis. For fixed-wing aircrafts such as the eBee, this axis runs from wing to wing.

Pitot Tube: the instrument on an aircraft that measures air pressure in order to calculate airspeed.

Point Cloud: a set of data points in a 3D coordinate system. These points are typically defined by X, Y and Z coordinates and additional information such as intensity, RGB value or class.

Post-processing kinematic (PPK): a kinematic technique that corrects geotag locations after the drone data has been captured and uploaded; an alternative technique to RTK.

Radio link: the quality of the wireless connection between the drone and the ground control station. Each radio unit consists of a transceiver and a directive antenna, typically operating at microwave frequencies in the range of 6-23 GHz.

Raster Data: in its simplest form, a raster consists of a matrix of cells (or pixels) organised into rows and columns (or a grid) where each cell contains a value representing information, such as RGB value, altitude or temperature.

Rasters: drone-captured digital photographs.

Real-Time Kinematic (RTK): a technique used to enhance the precision of position data derived from satellite-based positioning systems, which relies on a single reference station or interpolated virtual station to provide real-time corrections.

Red Green Blue (RGB): the visible region of the electromagnetic spectrum, from approximately 400 nm to 700 nm.

Reflectance Map: a display that provides scene radiance as a function of surface orientation.

Remotely Piloted Aircraft System (RPAS): describes a configurable set of remotely piloted aircraft elements.

Remote Sensing: the process of obtaining information about a physical element or surface from a distance, i.e. via UAV.

Revolutions Per Minute (RPM): describes the rotation speed of a motor or other machine.

Roll: an aircraft’s rotation about a longitudinal axis, running from nose to tail.

Small Unmanned Aerial System (SUAS): the industry standard term for “drone”.

Temporary flight restriction (TFR): a non-permanent restricted area for air travel determined by the FAA.

Unmanned Aerial Vehicle (UAV): an aircraft operated with no pilot on board plus its associated elements.

Vector Data: a representation of the world using points (e.g. featuring x, y, z coordinates), lines and polygons. Useful for storing data that has discrete boundaries such as country borders and parcels of land.

Virtual Reference Station (VRS): networks that use real-time kinematic (RTK) solutions to provide high-accuracy RTK Global Navigation Satellite Systems.

Waypoint: a series of defined coordinates that identify a specific point in space.

Working area: a dedicated area where the base station and the drone’s operating space are located.

3D Mesh: a type of digital recreation system, often used with Building Information Management (BIM), that overlays 3D point clouds with reference points in X, Y and Z axes to create a more fully form representation of an area and/or objects.