A drone is an unmanned aircraft. Drones are more formally known as unmanned aerial vehicles (UAVs) or unmanned aircraft systems. Essentially, a drone is a flying robot that can be remotely controlled or fly autonomously using software-controlled flight plans in its embedded systems, which work in conjunction with onboard sensors and a Global Positioning System (GPS).

UAVs were most often associated with the military. They were initially used for anti-aircraft target practice, intelligence gathering and, more controversially, as weapons platforms. For military purposes, drones can be sent on missions deemed too dangerous for human pilots in manned aircraft. Personally owned civilian drones, however, have a range of different professional and recreational uses, including the following:

·         Search and rescue.

·         Surveillance.

·         Traffic monitoring.

·         Weather monitoring.

·         Firefighting.

·         Personal use.

·         Drone-based photography.

·         Videography.

·         Agriculture.

·         Delivery services.

How do drones work?

Drones have two basic functions: flight mode and navigation.

To fly, drones must have a power source, such as a battery or fuel. They also commonly have rotors, propellers or wings and a frame. The frame of a drone is typically made of a lightweight, composite material to reduce weight and increase maneuverability.

Drones with propellers typically have four double-bladed propellers that stem off four arms connected to the frame. They generate lift using motors that rapidly spin the propellers. Drones that use wings, on the other hand, rely on the forward movement of the aircraft to push the wings through the air to generate lift.

Drones require a controller, which lets the operator use remote controls to launch, navigate and land the aircraft -- all while the pilot remains on the ground. The controllers communicate with the drone using radio waves, such as Wi-Fi. Drones also commonly have a camera onboard, which streams what it's seeing to the controller held by the pilot.

Some drones can fly on a set course automatically using a combination of obstacle avoidance sensors and GPS. A common implementation of this is the return to home function on some consumer drones.

What are common drone features and components?

Drones have many components, including the following:

·         Electronic speed controllers, which manage a motor's speed and direction.

·         Flight controller.

·         GPS module.

·         Battery.

·         Antenna.

·         Receiver.

·         Cameras.

·         Gimbals, which stabilize the camera from vibration, wind or other movement.

·         Sensors, including ultrasonic sensors and collision avoidance sensors.

·         Accelerometer, which measures speed.

·         Altimeter, which measures altitude.

Drone features vary based on the intended use. Examples of features include the following:

·         Various types of cameras with high-performance, zoom and gimbal steady cam and tilt capabilities.

·         Artificial intelligence (AI), which enables the drone to follow objects.

·         Augmented reality (AR) features that superimpose virtual objects on the drone's camera feed.

·         Media storage format.

·         Maximum flight time, which determines how long the drone can remain in the air.

·         Maximum speeds, including ascent and descent.

·         Hover accuracy.

·         Obstacle sensory range.

·         Altitude hold, which keeps the drone at a fixed altitude.

·         Live video feed.

·         Flight logs.

·         Automatic return to home.

·         Follow mode.

Navigational systems, such as GPS, are typically housed in the nose of a drone. The GPS on a drone communicates its precise location to the controller. An onboard altimeter can communicate altitude information as well as help keep the drone at a specific altitude if the controller designates one.

Drones can be equipped with sensors, including ultrasonic, laser or lidar distance sensors, time-of-flight sensors, chemical sensors and stabilization and orientation sensors. Visual sensors offer still and video data. Red, green and blue sensors collect standard visual RGB wavelengths, and multispectral sensors collect visible and nonvisible wavelengths, such as infrared and ultraviolet. Accelerometers, gyroscopes, magnetometers, barometers and GPS are also common drone features.

For example, thermal sensors enable surveillance and security applications, such as livestock monitoring and heat-signature detection. Hyperspectral sensors help identify minerals and vegetation, and are ideal for use in crop health, water quality and surface composition.

Some drones use sensors to detect obstacles and avoid collisions. Initially, these sensors were designed to detect objects in front of the drone. Some drones now provide obstacle detection in five directions: front, back, below, above and side to side.

For landing, drones use visual positioning systems with downward-facing cameras and ultrasonic sensors. The ultrasonic sensors determine how close the drone is to the ground.

What types of drones are available?

Drones are classified in several different ways, including by wing type, weight, range, power and activity type.

When classified by wing type, there are the following two main types of drone platforms:

1.     Rotor, including single-rotor and multi-rotor, such as tricopters, quadcopters, hex copters and octocopters.

2.     Fixed-wing, which includes drones that need forward movement to generate lift through the wings, as well as hybrid vertical takeoff and landing (VTOL) drones that don't require runways.

Personal drones often provide video or still-camera capabilities.

Drones can also be classified according to their weight, as follows:

·         Very small drones, which are 200 grams (.44 pounds) or less.

·         Small drones, which weigh up to 1,000 grams (2.20 pounds).

·         Medium drones, which weigh up to 44 pounds.

·         Large drones, which weigh more than 44 pounds.

Classified by range, drones can fit into one of the following categories:

·         Very close range, which can fly out to about one miles.

·         Close range, which can fly out to about 1 miles.

·         Short range, which can fly out to about 2 miles.

·         Midrange, which can fly out to about 3 miles.

·         Long range, which can fly out to more than 5 miles.

By power type, drones can be classified as follows:

·         Battery.

·         Gasoline.

·         Hydrogen fuel cell.

·         Solar.

By activity, drones can be classified into several types, which include, but aren't limited to the following:

·         Toy drones.

·         Photography or videography drones.

·         Racing drones.

·         First-person view (FPV) drones.

·         Search and rescue drones.

·         Military drones.

·         Construction drones.

·         Agriculture drones.

Personal drones

Many personal drones are available for consumer use. They've become standard Black Friday and Cyber Monday deals, offering high-definition video and still camera capabilities. Operators are often beginners who are looking to simply fly them for fun or racing. These drones usually weigh 10 pounds or less, but they can be less than a pound.

Examples of personal drones include the following:

·         Autel Evo Lite+, which is a competing option to the DJI mini but offers a 40-minute flight time and adjustable aperture.

·         BetaFPV Cetus Pro Kit, which is an FPV drone designed for beginners.

·         DJI Mini 4 Pro, which is a lightweight and compact drone for photography.

·         DJI Mavic 3 Pro, which is a powerful camera drone with omnidirectional obstacle sensing.

·         E max tiny hawk II, which is a racing drone designed for beginners.

·         Ryze Tello, which is a lightweight, compact and affordable option for beginners.

Commercial drones

Stronger, more capable drones are also available for use in commercial settings. Insitu, a Boeing company, offers the Scan Eagle, a UAV with a 10-foot wingspan that weighs 35 pounds. Insitu also builds the Integrator, an 81-pound aircraft with a 16-foot wingspan. Insitu drones don't take off from runways. Instead, they use VTOL capabilities in the company's launchers and recovery system. Sensors available include electro-optic imagers, mid-wave infrared imagers, infrared markers and laser rangefinders.

The Insitu Integrator extended range UAV sits on a Skyhook launcher.

In 2018, Boeing announced it had prototyped an unmanned electric VTOL cargo air vehicle capable of transporting up to a 500-pound payload. As of 2024, however, Boeing hasn't announced any updates to its production or sale.

Tethered drones are another option. They're physically tethered to a base station. Tethered systems can solve the power-supply challenge many drones face if the tether provides a direct power supply. For example, the Elistair Safe-T 2 tethered drone station offers 2,200 watts of power and can fly to heights of more than 200 feet, with data transfer rates of up to 200 Mbps.

In addition to Insitu and Elistair, other commercial drone manufacturers include the following:

·         3D Robotics Inc.

·         AeroVironment Inc.

·         Autel Robotics.

·         DJI.

·         Ehang.

·         Freefly

·         Parrot

·         Precision Hawk Inc.

·         Skydio

·         Yuneec.

Commercial and enterprise drone applications

Nonmilitary drone use has increased over the past decade. Beyond surveillance and delivery applications, UAVs are used for drone journalism, search and rescue, disaster response, asset protection, wildlife monitoring, firefighting, communications relay, healthcare and agriculture.

The integration of drones and internet of things (IoT) technology has created many enterprise applications. Drones working with on-ground IoT sensor networks can help agricultural companies monitor land and crops; energy company’s survey power lines and operational equipment; and insurance companies monitor properties for claims and policies.

A 2015 experiment in Austin, Texas, showed one way to combine drones and IoT. A security tech company teamed with a drone startup to hunt for ZigBee beacons to provide an overview of the IoT networks present in residential and business areas of the city. The companies reported that the results were quick and instructive.

From logistics to agriculture to security, unmanned aerial vehicles and IoT are often part of the same discussion. They offer ubiquitous connectivity and interactivity.

Other examples of how drone technology is used include the following:

·         Agriculture. Drones measure and record the height of crops. They use lidar remote sensing technology that illuminates the crop with a laser and calculates distance by measuring what is reflected back. This can help farmers optimize agricultural production and promote sustainable farming practices.

·         Biological monitoring. Drones with biological sensors fly to unsafe areas to take air or water quality readings. They can also check for the presence of specific microorganisms and atmospheric elements.

·         Wildfire monitoring. Firefighters use drones to survey an affected area to determine the extent of the damage and how fast a fire is spreading. Images taken provide details of the damage.

·         Sports coverage. Television networks use drones to capture sporting event footage, such as taped and live flyover footage, that would otherwise be difficult to capture. The use of drones must comply with Federal Aviation Administration (FAA) regulations, as well as sports league, venue and local law enforcement agency rules.

The history of drones

Drones date back to 1849 Italy, when Venice was fighting for its independence from Austria. Austrian soldiers attacked Venice with hot-air, hydrogen- and helium-filled balloons equipped with bombs.

The first pilotless radio-controlled aircraft was used in World War I. In 1917, the U.S. Army developed the experimental Kettering Bug, an unmanned flying bomb aircraft, which was never used operationally in combat.

The first generally used drone appeared in 1935 as a full-size retooling of the de Havilland DH.82B Queen Bee biplane. It was fitted with a radio and servomechanism-operated controls in the back seat. The plane could be conventionally piloted from the front seat, but generally flew unmanned for artillery gunners in training to shoot.

The term drone dates to this initial use, a play on the Queen Bee nomenclature.

UAV technology continued to be of interest to the military, but it was often unreliable and costly. After concerns about the shooting down of spy planes arose, the military revisited the topic of UAVs. Military drones soon took on roles of dropping leaflets and acting as spying decoys.

Soldiers of the Bundeswehr, the German armed forces, recover a KZO reconnaissance drone following a successful mission during Thunder Storm 2018 multinational NATO military exercises on June 7, 2018, near Pabrade, Lithuania.

In 1982, the Israeli Air Force used UAVs against the Syrian fleet with minimal loss of Israeli forces. The Israeli UAVs acted as decoys, jammed communication and offered real-time video reconnaissance.

Drones have continued to be a mainstay as part of military IoT in the following roles:

·         Intelligence.

·         Aerial surveillance.

·         Force protection.

·         Search and rescue.

·         Artillery spotting.

·         Target following and acquisition.

·         Battle damage assessment.

·         Reconnaissance.

·         Weaponry.