These developments also inspired the construction of the Kettering Bug
The Kettering Bug was an experimental unmanned aerial torpedo, a forerunner of present-day cruise missiles. It was capable of striking ground targets up to from its launch point, while traveling at speeds of . The Bug's costly design and operat ...
by Charles Kettering
Charles Franklin Kettering (August 29, 1876 – November 25, 1958) sometimes known as Charles Fredrick Kettering was an American inventor, engineer, businessman, and the holder of 186 patents.
For the list of patents issued to Kettering, see, Le ...
from Dayton, Ohio
Dayton () is the sixth-largest city in the U.S. state of Ohio and the county seat of Montgomery County. A small part of the city extends into Greene County. The 2020 U.S. census estimate put the city population at 137,644, while Greater Day ...
and the Hewitt-Sperry Automatic Airplane
The Hewitt-Sperry Automatic Airplane was a project undertaken during World War I to develop a flying bomb, or pilotless aircraft capable of carrying explosives to its target. It is considered by some to be a precursor of the cruise missile.
Co ...
– initially meant as an uncrewed plane that would carry an explosive payload to a predetermined target. Development continued during World War I, when the Dayton-Wright Airplane Company
The Dayton-Wright Company was formed in 1917, on the declaration of war between the United States and Germany, by a group of Ohio investors that included Charles F. Kettering and Edward A. Deeds of Dayton Engineering Laboratories Company ( DELCO) ...
invented a pilotless aerial torpedo that would explode at a preset time.
The film star and
model-airplane
A model aircraft is a small unmanned aircraft. Many are replicas of real aircraft. Model aircraft are divided into two basic groups: flying and non-flying. Non-flying models are also termed static, display, or shelf models.
Aircraft manufactur ...
enthusiast
Reginald Denny developed the first scaled remote piloted vehicle in 1935.
Soviet researchers experimented with controlling
Tupolev TB-1
The Tupolev TB-1 (development name ANT-4) was a Soviet bomber aircraft, an angular monoplane that served as the backbone of the Soviet bomber force for many years, and was the first large all-metal aircraft built in the Soviet Union.
Design and ...
bombers remotely in the late 1930s.
World War II
In 1940 Denny started the
Radioplane Company
The Radioplane Company was an American aviation company that produced drone aircraft primarily for use as gunnery targets. During World War II, they produced over 9,400 of their Radioplane OQ-3 model, a propeller-powered monoplane, making it the ...
and more models emerged during
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
used both to train antiaircraft gunners and to fly attack-missions.
Nazi Germany
Nazi Germany (lit. "National Socialist State"), ' (lit. "Nazi State") for short; also ' (lit. "National Socialist Germany") (officially known as the German Reich from 1933 until 1943, and the Greater German Reich from 1943 to 1945) was ...
produced and used various UAV aircraft during the war, like the
Argus As 292
The Argus As 292 was originally developed in 1939 as a small, remote-controlled unmanned anti-aircraft target drone. A short-range reconnaissance version was also developed. The success of the project led to the Argus Fernfeuer UAV proposal.
Dev ...
and the
V-1 flying bomb
The V-1 flying bomb (german: Vergeltungswaffe 1 "Vengeance Weapon 1") was an early cruise missile. Its official Ministry of Aviation (Nazi Germany), Reich Aviation Ministry () designation was Fi 103. It was also known to the Allies as the buz ...
with a
jet engine
A jet engine is a type of reaction engine discharging a fast-moving jet of heated gas (usually air) that generates thrust by jet propulsion. While this broad definition can include rocket, Pump-jet, water jet, and hybrid propulsion, the term ...
.
Postwar period
After World War II development continued in vehicles such as the American
JB-4
The JB-4, also known as MX-607, was an early American air-to-surface missile developed by the United States Army Air Forces during World War II. Using television/radio-command guidance, the JB-4 reached the flight-testing stage before being can ...
(using television/radio-command guidance), the Australian
GAF Jindivik
The GAF Jindivik is a radio-controlled target drone produced by the Australian Government Aircraft Factories (GAF). The name is from an Aboriginal Australian word meaning "the hunted one". Two manually-controlled prototypes, were built as the GAF ...
and
Teledyne Ryan
The Ryan Aeronautical Company was founded by T. Claude Ryan in San Diego, California, in 1934. It became part of Teledyne in 1969, and of Northrop Grumman when the latter company purchased Ryan in 1999. Ryan built several historically and tec ...
Firebee I of 1951, while companies like
Beechcraft
Beechcraft is an American brand of civil aviation and military aircraft owned by Textron Aviation since 2014, headquartered in Wichita, Kansas. Originally, it was a brand of Beech Aircraft Corporation, an American manufacturer of general avi ...
offered their
Model 1001 for the
U.S. Navy
The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage o ...
in 1955.
Nevertheless, they were little more than remote-controlled airplanes until the
Vietnam War
The Vietnam War (also known by #Names, other names) was a conflict in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. It was the second of the Indochina Wars and was officially fought between North Vie ...
.
In 1959 the
U.S. Air Force
The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Sign ...
, concerned about losing pilots over hostile territory, began planning for the use of uncrewed aircraft. Planning intensified after the
Soviet Union
The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national ...
shot down a U-2 in 1960. Within days, a highly-
classified UAV program started under the code name of "Red Wagon". The August 1964
clash in the Tonkin Gulf between naval units of the U.S. and the
North Vietnamese Navy
The Vietnam People's Navy (VPN; vi, Hải quân nhân dân Việt Nam), or the Naval Service (), also known as the Vietnamese People's Navy or simply Vietnam/Vietnamese Navy (), is the naval branch of the Vietnam People's Army and is responsi ...
initiated America's highly-classified UAVs (
Ryan Model 147
The Ryan Model 147 Lightning Bug is a jet-powered drone, or unmanned aerial vehicle, produced and developed by Ryan Aeronautical from the earlier Ryan Firebee target drone series.
Beginning in 1962, the Model 147 was introduced as a reconnai ...
,
Ryan AQM-91 Firefly
The Ryan AQM-91 Firefly was a developmental drone developed during the Vietnam War to perform long-range reconnaissance, especially into China.
Development
The Ryan Model 147 Lightning Bug reconnaissance drone was enjoying success in Vietnam ...
,
Lockheed D-21) into their first combat missions of the
Vietnam War
The Vietnam War (also known by #Names, other names) was a conflict in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. It was the second of the Indochina Wars and was officially fought between North Vie ...
. When the Chinese government showed photographs of downed U.S. UAVs via ''Wide World Photos'', the official U.S. response was "no comment".
During the
War of Attrition
The War of Attrition ( ar, حرب الاستنزاف, Ḥarb al-Istinzāf; he, מלחמת ההתשה, Milhemet haHatashah) involved fighting between Israel and Egypt, Jordan, the Palestine Liberation Organisation (PLO) and their allies from ...
(1967–1970) in the Middle East, Israeli intelligence tested the first tactical UAVs installed with
reconnaissance
In military operations, reconnaissance or scouting is the exploration of an area by military forces to obtain information about enemy forces, terrain, and other activities.
Examples of reconnaissance include patrolling by troops (skirmisher ...
cameras, which successfully returned photos from across the Suez Canal. This was the first time that tactical UAVs that could be launched and landed on any short runway (unlike the heavier jet-based UAVs) were developed and tested in battle.
In the 1973
Yom Kippur War
The Yom Kippur War, also known as the Ramadan War, the October War, the 1973 Arab–Israeli War, or the Fourth Arab–Israeli War, was an armed conflict fought from October 6 to 25, 1973 between Israel and a coalition of Arab states led by Egy ...
,
Israel
Israel (; he, יִשְׂרָאֵל, ; ar, إِسْرَائِيل, ), officially the State of Israel ( he, מְדִינַת יִשְׂרָאֵל, label=none, translit=Medīnat Yīsrāʾēl; ), is a country in Western Asia. It is situated ...
used UAVs as decoys to spur opposing forces into wasting expensive anti-aircraft missiles. After the 1973 Yom Kippur war, a few key people from the team that developed this early UAV joined a small startup company that aimed to develop UAVs into a commercial product, eventually purchased by Tadiran and leading to the development of the first Israeli UAV.
In 1973 the U.S. military officially confirmed that they had been using UAVs in Southeast Asia (Vietnam). Over 5,000 U.S. airmen had been killed and over 1,000 more were
missing
Missing or The Missing may refer to:
Film
* ''Missing'' (1918 film), an American silent drama directed by James Young
* ''Missing'' (1982 film), an American historical drama directed by Costa-Gavras
* ''Missing'' (2007 film) (''Vermist''), a Bel ...
or
captured. The USAF
100th Strategic Reconnaissance Wing flew about 3,435 UAV missions during the war at a cost of about 554 UAVs lost to all causes. In the words of USAF
General
A general officer is an Officer (armed forces), officer of highest military ranks, high rank in the army, armies, and in some nations' air forces, space forces, and marines or naval infantry.
In some usages the term "general officer" refers t ...
George S. Brown, Commander,
Air Force Systems Command
The Air Force Systems Command (AFSC) is an inactive United States Air Force Major Command. It was established in April 1951, being split off from Air Materiel Command. The mission of AFSC was Research and Development for new weapons systems.
Ove ...
, in 1972, "The only reason we need (UAVs) is that we don't want to needlessly expend the man in the cockpit." Later that year, General
John C. Meyer, Commander in Chief,
Strategic Air Command
Strategic Air Command (SAC) was both a United States Department of Defense Specified Command and a United States Air Force (USAF) Major Command responsible for command and control of the strategic bomber and intercontinental ballistic missile ...
, stated, "we let the drone do the high-risk flying ... the loss rate is high, but we are willing to risk more of them ...they save lives!"
During the 1973
Yom Kippur War
The Yom Kippur War, also known as the Ramadan War, the October War, the 1973 Arab–Israeli War, or the Fourth Arab–Israeli War, was an armed conflict fought from October 6 to 25, 1973 between Israel and a coalition of Arab states led by Egy ...
, Soviet-supplied
surface-to-air missile
A surface-to-air missile (SAM), also known as a ground-to-air missile (GTAM) or surface-to-air guided weapon (SAGW), is a missile designed to be launched from the ground to destroy aircraft or other missiles. It is one type of anti-aircraft syst ...
-batteries in
Egypt
Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia via a land bridge formed by the Sinai Peninsula. It is bordered by the Mediter ...
and
Syria
Syria ( ar, سُورِيَا or سُورِيَة, translit=Sūriyā), officially the Syrian Arab Republic ( ar, الجمهورية العربية السورية, al-Jumhūrīyah al-ʻArabīyah as-Sūrīyah), is a Western Asian country loc ...
caused heavy damage to Israeli
fighter jet
Fighter aircraft are fixed-wing military aircraft designed primarily for air-to-air combat. In military conflict, the role of fighter aircraft is to establish air superiority of the battlespace. Domination of the airspace above a battlefield ...
s. As a result, Israel developed the
IAI Scout as the first UAV with real-time surveillance. The images and radar decoys provided by these UAVs helped Israel to
completely neutralize the Syrian
air defense
Anti-aircraft warfare, counter-air or air defence forces is the battlespace response to aerial warfare, defined by NATO as "all measures designed to nullify or reduce the effectiveness of hostile air action".AAP-6 It includes surface based, ...
s at the start of the
1982 Lebanon War
The 1982 Lebanon War, dubbed Operation Peace for Galilee ( he, מבצע שלום הגליל, or מבצע של"ג ''Mivtsa Shlom HaGalil'' or ''Mivtsa Sheleg'') by the Israeli government, later known in Israel as the Lebanon War or the First L ...
, resulting in no pilots downed.
In Israel in 1987, UAVs were first used as proof-of-concept of super-agility, post-stall controlled flight in combat-flight simulations that involved tailless, stealth-technology-based, three-dimensional thrust vectoring flight-control, and jet-steering.
Modern UAVs
![STM_Kargu](https://upload.wikimedia.org/wikipedia/commons/6/69/STM_Kargu.png)
With the maturing and miniaturization of applicable technologies in the 1980s and 1990s, interest in UAVs grew within the higher echelons of the U.S. military. In the 1990s, the U.S. DoD gave a contract to
AAI Corporation
AAI Corporation is an aerospace and defense development and manufacturing firm, located in Hunt Valley, Maryland, US. Formerly a wholly owned subsidiary of United Industrial Corporation, AAI was acquired by Textron in 2007. It currently operates ...
along with Israeli company Malat. The U.S. Navy bought the AAI Pioneer UAV that AAI and Malat developed jointly. Many of these UAVs saw service in the
1991 Gulf War
The Gulf War was a 1990–1991 armed campaign waged by a 35-country military coalition in response to the Iraqi invasion of Kuwait. Spearheaded by the United States, the coalition's efforts against Iraq were carried out in two key phases: ...
. UAVs demonstrated the possibility of cheaper, more capable fighting-machines, deployable without risk to aircrews. Initial generations primarily involved
surveillance aircraft
A surveillance aircraft is an aircraft used for surveillance. They are operated by military forces and other government agencies in roles such as intelligence gathering, battlefield surveillance, airspace surveillance, reconnaissance, observa ...
, but
some carried armaments, such as the
General Atomics MQ-1 Predator
The General Atomics MQ-1 Predator (often referred to as the predator drone) is an American remotely piloted aircraft (RPA) built by General Atomics that was used primarily by the United States Air Force (USAF) and Central Intelligence Agency ( ...
, that launched
AGM-114 Hellfire
The AGM-114 Hellfire is an air-to-ground missile (AGM) first developed for anti-armor use, later developed for precision drone strikes against other target types, especially high-value targets. It was originally developed under the name '' Heli ...
air-to-ground missile
An air-to-surface missile (ASM) or air-to-ground missile (AGM) is a missile designed to be launched from military aircraft at targets on land or sea. There are also unpowered guided glide bombs not considered missiles. The two most common p ...
s.
CAPECON
The CAPECON project (civil UAV applications and economic effectivity of potential configuration solutions) was a European Union initiative to develop UAV, UAVs.
The project ran from 1 May 2002 to 31 December 2005. The total cost was 5 136 539 e ...
, a
European Union
The European Union (EU) is a supranational political and economic union of member states that are located primarily in Europe. The union has a total area of and an estimated total population of about 447million. The EU has often been des ...
project
A project is any undertaking, carried out individually or collaboratively and possibly involving research or design, that is carefully planned to achieve a particular goal.
An alternative view sees a project managerially as a sequence of even ...
to develop UAVs,
ran from 1 May 2002 to 31 December 2005.
the
United States Air Force
The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Signal ...
(USAF) employed 7,494 UAVs almost one in three USAF aircraft.
The
Central Intelligence Agency
The Central Intelligence Agency (CIA ), known informally as the Agency and historically as the Company, is a civilian foreign intelligence service of the federal government of the United States, officially tasked with gathering, processing, ...
also operated UAVs. By 2013 at least 50 countries used UAVs. China, Iran, Israel, Pakistan, Turkey, and others designed and built their own varieties. The use of drones has continued to increase.
[Sayler (2015)] Due to their wide proliferation, no comprehensive list of UAV systems exists.
[Singer, Peter W]
"A Revolution Once More: Unmanned Systems and the Middle East"
The Brookings Institution
November 2009.[Franke, Ulrike Esther The global diffusion of unmanned aerial vehicles (UAVs) or 'drones'" in Mike Aaronson (ed) Precision Strike Warfare and International Intervention, Routledge 2015.]
The development of smart technologies and improved electrical-power systems led to a parallel increase in the use of drones for consumer and general aviation activities. As of 2021,
quadcopter
A quadcopter or quadrotor is a type of helicopter with four Helicopter rotor, rotors.
Although quadrotor helicopters and convertiplanes have long been flown experimentally, the configuration remained a curiosity until the arrival of the moder ...
drones exemplify the widespread popularity of hobby
radio-controlled aircraft
A radio-controlled aircraft (often called RC aircraft or RC plane) is a small flying machine that is controlled remotely by an operator on the ground using a hand-held radio transmitter. The transmitter continuously communicates with a receiver ( ...
and toys, however the use of UAVs in commercial and general aviation is limited by a lack of autonomy and by new regulatory environments which require line-of-sight contact with the pilot.
In 2020 a
Kargu 2 drone hunted down and attacked a human target in
Libya
Libya (; ar, ليبيا, Lībiyā), officially the State of Libya ( ar, دولة ليبيا, Dawlat Lībiyā), is a country in the Maghreb region in North Africa. It is bordered by the Mediterranean Sea to the north, Egypt to Egypt–Libya bo ...
, according to a report from the
UN Security Council
The United Nations Security Council (UNSC) is one of the six principal organs of the United Nations (UN) and is charged with ensuring international peace and security, recommending the admission of new UN members to the General Assembly, and ...
's Panel of Experts on Libya, published in March 2021. This may have been the first time an
autonomous killer-robot armed with lethal weaponry attacked human beings.
Superior drone technology, specifically the
Bayraktar TB2
The Bayraktar TB2 is a medium-altitude long-endurance (MALE) unmanned combat aerial vehicle (UCAV) capable of remotely controlled or autonomous flight operations. It is manufactured by the Turkish company Baykar Makina Sanayi ve Ticaret A.Ş ...
, played a role in Azerbaijan's successes in the
2020 Nagorno-Karabakh war
The Second Nagorno-Karabakh War was an armed conflict in 2020 that took place in the disputed region of Nagorno-Karabakh and Armenian-occupied territories surrounding Nagorno-Karabakh, the surrounding territories. It was a major escalation of ...
against Armenia.
![Dragonfly-landing](https://upload.wikimedia.org/wikipedia/commons/3/3a/Dragonfly-landing.png)
UAVs are also used in
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research.
NASA was established in 1958, succeeding t ...
missions. The
Dragonfly spacecraft is being developed, and is aiming to reach and examine
Saturn
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine and a half times that of Earth. It has only one-eighth the average density of Earth; h ...
's moon
Titan. Its primary goal is to roam around the surface, expanding the amount of area to be researched previously seen by
Landers. As a UAV, Dragonfly allows examination of potentially diverse types of soil. The drone is set to launch in 2027, and is estimated to take a seven more years to reach the Saturnian system.
Design
![UAV Physical and hardware](https://upload.wikimedia.org/wikipedia/commons/5/5d/UAV_Physical_and_hardware.jpg)
Crewed and uncrewed aircraft of the same type generally have recognizably similar physical components. The main exceptions are the
cockpit
A cockpit or flight deck is the area, usually near the front of an aircraft or spacecraft, from which a Pilot in command, pilot controls the aircraft.
The cockpit of an aircraft contains flight instruments on an instrument panel, and the ...
and
environmental control system
In aeronautics, an environmental control system (ECS) of an aircraft is an essential component which provides air supply, thermal control and cabin pressurization for the crew and passengers. Additional functions include the cooling of avionic ...
or
life support system
A life-support system is the combination of equipment that allows survival in an environment or situation that would not support that life in its absence. It is generally applied to systems supporting human life in situations where the outsid ...
s. Some UAVs carry payloads (such as a camera) that weigh considerably less than an adult human, and as a result, can be considerably smaller. Though they carry heavy payloads, weaponized military UAVs are lighter than their crewed counterparts with comparable armaments.
Small civilian UAVs have no
life-critical system
A safety-critical system (SCS) or life-critical system is a system whose failure or malfunction may result in one (or more) of the following outcomes:
* death or serious injury to people
* loss or severe damage to equipment/property
* environme ...
s, and can thus be built out of lighter but less sturdy materials and shapes, and can use less robustly tested electronic control systems. For small UAVs, the
quadcopter
A quadcopter or quadrotor is a type of helicopter with four Helicopter rotor, rotors.
Although quadrotor helicopters and convertiplanes have long been flown experimentally, the configuration remained a curiosity until the arrival of the moder ...
design has become popular, though this layout is rarely used for crewed aircraft. Miniaturization means that less-powerful propulsion technologies can be used that are not feasible for crewed aircraft, such as small electric motors and batteries.
Control systems for UAVs are often different than crewed craft. For remote human control, a camera and video link almost always replace the cockpit windows; radio-transmitted digital commands replace physical cockpit controls.
Autopilot
An autopilot is a system used to control the path of an aircraft, marine craft or spacecraft without requiring constant manual control by a human operator. Autopilots do not replace human operators. Instead, the autopilot assists the operator' ...
software is used on both crewed and uncrewed aircraft, with varying feature sets.
Aircraft configuration
The primary difference from manned aeroplanes is the lack of need for a cockpit area and its windows. However some types are adapted from piloted examples, or are designed for optional piloted or unmanned operational modes.
Air safety
Aviation safety is the study and practice of managing risks in aviation. This includes preventing aviation accidents and incidents through research, educating air travel personnel, passengers and the general public, as well as the design of airc ...
is also less of a critical requirement for unmanned aircraft, allowing the designer greater freedom to experiment. These two factors have led to a great variety of airframe and engine configurations in UAVs.
For conventional flight the
flying wing
A flying wing is a tailless fixed-wing aircraft that has no definite fuselage, with its crew, payload, fuel, and equipment housed inside the main wing structure. A flying wing may have various small protuberances such as pods, nacelles, blis ...
and
blended wing body
A blended wing body (BWB), also known as blended body or hybrid wing body (HWB), is a fixed-wing aircraft having no clear dividing line between the wings and the main body of the craft. The aircraft has distinct wing and body structures, which ar ...
offer light weight combined with low
drag and
stealth, and are popular configurations. Larger types which carry a variable payload are more likely to feature a distinct
fuselage
The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraft t ...
with a tail for stability, control and trim, although the
wing configuration
The wing configuration of a fixed-wing aircraft (including both glider (aircraft), gliders and powered aeroplanes) is its arrangement of lifting and related surfaces.
Aircraft designs are often classified by their wing configuration. For examp ...
s in use vary widely.
For vertical flight, the tailless
quadcopter
A quadcopter or quadrotor is a type of helicopter with four Helicopter rotor, rotors.
Although quadrotor helicopters and convertiplanes have long been flown experimentally, the configuration remained a curiosity until the arrival of the moder ...
requires a relatively simple control system and is common for smaller UAVs. However the mechanism does not scale well to larger aircraft, which tend to use a conventional single rotor with collective and cyclic pitch control, along with a stabilising tail rotor.
Propulsion
Traditional
internal combustion
An internal combustion engine (ICE or IC engine) is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combus ...
and
jet engine
A jet engine is a type of reaction engine discharging a fast-moving jet of heated gas (usually air) that generates thrust by jet propulsion. While this broad definition can include rocket, Pump-jet, water jet, and hybrid propulsion, the term ...
s remain in use for drones requiring long range. However for shorter-range missions electric power has almost entirely taken over. The distance record for a UAV (built from balsa wood and mylar skin) across the North Atlantic Ocean is held by a gasoline model airplane or UAV. Manard Hill "in 2003 when one of his creations flew 1,882 miles across the Atlantic Ocean on less than a gallon of fuel" holds this record.
Besides the traditional piston engine, the
Wankel rotary engine
The Wankel engine (, ) is a type of internal combustion engine using an eccentric rotary design to convert pressure into rotating motion. It was invented by German engineer Felix Wankel, and designed by German engineer Hanns-Dieter Paschke. T ...
is used by some drones. This type offers high power output for lower weight, with quieter and more vibration-free running. Claims have also been made for improved reliability and greater range.
Small drones mostly use
lithium-polymer batteries (Li-Po), while some larger vehicles have adopted the a
hydrogen fuel cell
A fuel cell is an electrochemical cell that converts the chemical energy of a fuel (often hydrogen fuel, hydrogen) and an oxidizing agent (often oxygen) into electricity through a pair of redox reactions. Fuel cells are different from most bat ...
. The energy density of modern Li-Po batteries is far less than gasoline or hydrogen. However electric motors are cheaper, lighter and quieter. Complex multi-engine, multi-propeller installations are under development with the goal of improving aerodynamic and propulsive efficiency. For such complex power installations,
Battery elimination circuitry (BEC) may be used to centralize power distribution and minimize heating, under the control of a
microcontroller unit
A microcontroller (MCU for ''microcontroller unit'', often also MC, UC, or μC) is a small computer on a single VLSI integrated circuit (IC) chip. A microcontroller contains one or more CPUs ( processor cores) along with memory and programmabl ...
(MCU).
Ornithopters – wing propulsion
Flapping-wing
ornithopter
An ornithopter (from Greek ''ornis, ornith-'' "bird" and ''pteron'' "wing") is an aircraft that flies by flapping its wings. Designers sought to imitate the flapping-wing flight of birds, bats, and insects. Though machines may differ in form, th ...
s, imitating birds or insects, have been flown as
microUAVs. Their inherent stealth recommends them for spy missions.
Sub-1g microUAVs inspired by flies, albeit using a power tether, have been able to "land" on vertical surfaces. Other projects mimic the flight of beetles and other insects.
Computer control systems
![AbuseMark AfroFlight Naze 32 Flight Controller rev5 white](https://upload.wikimedia.org/wikipedia/commons/d/dd/AbuseMark_AfroFlight_Naze_32_Flight_Controller_rev5_white.jpg)
UAV computing capability followed the advances of computing technology, beginning with analog controls and evolving into microcontrollers, then
system-on-a-chip
A system on a chip or system-on-chip (SoC ; pl. ''SoCs'' ) is an integrated circuit that integrates most or all components of a computer or other electronic system. These components almost always include a central processing unit (CPU), memory ...
(SOC) and
single-board computer
A single-board computer (SBC) is a complete computer built on a single circuit board, with microprocessor(s), memory, input/output (I/O) and other features required of a functional computer. Single-board computers are commonly made as demonstrati ...
s (SBC).
System hardware for small UAVs is often called the flight controller (FC), flight controller board (FCB) or autopilot. Common
UAV-systems control hardware typically incorporate a primary microprocessor, a secondary or failsafe processor, and sensors such as accelerometers, gyroscopes, magnetometers, and barometers into a single module.
Architecture
Sensors
Position and movement sensors give information about the aircraft state. Exteroceptive sensors deal with external information like distance measurements, while exproprioceptive ones correlate internal and external states.
Non-cooperative sensors are able to detect targets autonomously so they are used for separation assurance and collision avoidance.
Degrees of freedom (DOF) refers to both the amount and quality of sensors on board: 6 DOF implies 3-axis gyroscopes and accelerometers (a typical
inertial measurement unit
An inertial measurement unit (IMU) is an electronic device that measures and reports a body's specific force, angular rate, and sometimes the orientation of the body, using a combination of accelerometers, gyroscopes, and sometimes magnetometer ...
IMU), 9 DOF refers to an IMU plus a compass, 10 DOF adds a barometer and 11 DOF usually adds a GPS receiver.
Actuators
UAV
actuator
An actuator is a component of a machine that is responsible for moving and controlling a mechanism or system, for example by opening a valve. In simple terms, it is a "mover".
An actuator requires a control device (controlled by control signal) a ...
s include
digital electronic speed controllers (which control the
RPM
Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or with the notation min−1) is a unit of rotational speed or rotational frequency for rotating machines.
Standards
ISO 80000-3:2019 defines a unit of rotation as the dimensionl ...
of the motors) linked to motors/
engine
An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy.
Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power gen ...
s and
propeller
A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon ...
s,
servomotor
A servomotor (or servo motor) is a rotary actuator or linear actuator that allows for precise control of angular or linear position, velocity and acceleration. It consists of a suitable motor coupled to a sensor for position feedback. It also r ...
s (for planes and helicopters mostly), weapons, payload actuators, LEDs and speakers.
Software
UAV software is called the flight stack or autopilot. The purpose of the flight stack is to obtain data from sensors, control motors to ensure UAV stability, and facilitate ground control and mission planning communication.
UAVs are
real-time
Real-time or real time describes various operations in computing or other processes that must guarantee response times within a specified time (deadline), usually a relatively short time. A real-time process is generally one that happens in defined ...
systems that require rapid response to changing sensor data. As a result, UAVs rely on single-board computers for their computational needs. Examples of such single-board computers include
Raspberry Pi
Raspberry Pi () is a series of small single-board computers (SBCs) developed in the United Kingdom by the Raspberry Pi Foundation in association with Broadcom. The Raspberry Pi project originally leaned towards the promotion of teaching basic ...
s,
Beagleboards, etc. shielded with
NavIO,
PXFMini, etc. or designed from scratch such as
NuttX
NuttX is a free and open-source Real-Time Operating System (RTOS) with an emphasis on technical standards compliance and on having a small footprint. Scalable from 8-bit to 64-bit microcontroller environments, the main governing standards in ...
, preemptive-
RT Linux,
Xenomai
Xenomai is a real-time development software framework cooperating with the Linux kernel to provide wikt:pervasive, pervasive, interface-agnostic, hard real-time computing support to user space application software seamlessly integrated into the Li ...
,
Orocos-Robot Operating System or
DDS-ROS 2.0.
Civil-use open-source stacks include:
*
Agilicious (also
open-source hardware
Open-source hardware (OSH) consists of physical artifacts of technology designed and offered by the open-design movement. Both free and open-source software (FOSS) and open-source hardware are created by this open-source culture movement and a ...
)
*
ArduCopter
ArduPilot:Copter previously named APM:Copter or ArduCopter is the multicopter unmanned aerial vehicle version of the open-source ArduPilot autopilot platform.
The free software approach from ArduCopter is similar to that of the Paparazzi Projec ...
* CrazyFlie
*
KKMultiCopter
*
MultiWii
**
BaseFlight (forked from MultiWii)
***
CleanFlight (forked from BaseFlight)
****
BetaFlight (forked from CleanFlight)
****
iNav (forked from CleanFlight)
****
RaceFlight (forked from CleanFlight)
*
OpenPilot
** dRonin (forked from OpenPilot)
** LibrePilot (forked from OpenPilot)
** TauLabs (forked from OpenPilot)
* Paparazzi Project, Paparazzi
* PX4 autopilot
** DroneCode (Umbrella organization managing PX4 within the Linux Foundation)
Due to the open-source nature of UAV software, they can be customized to fit specific applications. For example, researchers from the Technical University of Košice have replaced the default control algorithm of the PX4 autopilot. This flexibility and collaborative effort has led to a large number of different open-source stacks, some of which are forked from others, such as CleanFlight, which is forked from BaseFlight and from which three other stacks are forked from.
Loop principles
![UAV Flight control](https://upload.wikimedia.org/wikipedia/commons/4/4d/UAV_Flight_control.jpg)
UAVs employ open-loop, closed-loop or hybrid control architectures.
* Open-loop controller, Open loop This type provides a positive control signal (faster, slower, left, right, up, down) without incorporating feedback from sensor data.
* Closed-loop transfer function, Closed loop This type incorporates sensor feedback to adjust behavior (reduce speed to reflect tailwind, move to altitude 300 feet). The PID controller is common. Sometimes, Feed forward (control), feedforward is employed, transferring the need to close the loop further.
Communications
UAVs use a radio for control and Data link, exchange of video and other data. Early UAVs had only narrowband uplink. Downlinks came later. These bi-directional narrowband radio links carried command and control (C&C) and telemetry data about the status of aircraft systems to the remote operator.
In most modern UAV applications, video transmission is required. So instead of having separate links for C&C, telemetry and video traffic, a broadband link is used to carry all types of data. These broadband links can leverage quality of service techniques and carry TCP/IP traffic that can be routed over the Internet.
The radio signal from the operator side can be issued from either:
* Ground control – a human operating a Transmitter, radio transmitter/receiver, a smartphone, a tablet, a computer, or the original meaning of a UAV ground control station, military ground control station (GCS).
* Remote network system, such as satellite duplex data links for some Armed forces, military powers. Downstream digital video over mobile networks has also entered consumer markets, while direct UAV control uplink over the cellular mesh and LTE have been demonstrated and are in trials.
* Another aircraft, serving as a relay or mobile control station military manned-unmanned teaming (MUM-T).
Modern networking standards have explicitly considered drones and therefore include optimizations. The 5G standard has mandated reduced user plane latency to 1ms while using ultra-reliable and low-latency communications.
Autonomy
![Degrees of autonomy](https://upload.wikimedia.org/wikipedia/commons/5/5a/Degrees_of_autonomy.jpg)
The level of autonomy in UAVs varies widely. UAV manufacturers often build in specific autonomous operations, such as:
* Self-level: attitude stabilization on the pitch and roll axes.
* Altitude hold: The aircraft maintains its altitude using barometric pressure and/or GPS data.
* Hover/position hold: Keep level pitch and roll, stable yaw heading and altitude while maintaining position using GNSS or inertial sensors.
* Headless mode: Pitch control relative to the position of the pilot rather than relative to the vehicle's axes.
* Care-free: automatic roll and yaw control while moving horizontally
* Take-off and landing (using a variety of aircraft or ground-based sensors and systems; see also "autoland")
* Failsafe: automatic landing or return-to-home upon loss of control signal
* Return-to-home: Fly back to the point of takeoff (often gaining altitude first to avoid possible intervening obstructions such as trees or buildings).
* Follow-me: Maintain relative position to a moving pilot or other object using GNSS, image recognition or homing beacon.
* GPS waypoint navigation: Using GNSS to navigate to an intermediate location on a travel path.
* Orbit around an object: Similar to Follow-me but continuously circle a target.
* Pre-programmed aerobatics (such as rolls and loops)
One approach to quantifying autonomous capabilities is based on OODA loop, OODA terminology, as suggested by a 2002 US Air Force Research Laboratory report, and used in the table on the right.
![X-47B receives fuel from an Omega K-707 tanker while operating in the Atlantic Test Ranges](https://upload.wikimedia.org/wikipedia/commons/b/b2/X-47B_receives_fuel_from_an_Omega_K-707_tanker_while_operating_in_the_Atlantic_Test_Ranges.jpg)
Full autonomy is available for specific tasks, such as airborne refueling or ground-based battery switching.
Other functions available or under development include; collective flight, real-time Collision avoidance system, collision avoidance, wall following, corridor centring, simultaneous localization and mapping and Swarm robotics, swarming, cognitive radio and machine learning. In this context, computer vision can play an important role for automatically ensuring flight safety.
Performance considerations
Flight envelope
UAVs can be programmed to perform aggressive maneuvers or landing/perching on inclined surfaces, and then to climb toward better communication spots. Some UAVs can control flight with varying flight modelisation, such as VTOL designs.
UAVs can also implement perching on a flat vertical surface.
Endurance
![Flight time against mass of small drones](https://upload.wikimedia.org/wikipedia/commons/b/b6/Flight_time_against_mass_of_small_drones.svg)
UAV endurance is not constrained by the physiological capabilities of a human pilot.
Because of their small size, low weight, low vibration and high power to weight ratio, Wankel rotary engines are used in many large UAVs. Their engine rotors cannot seize; the engine is not susceptible to shock-cooling during descent and it does not require an enriched fuel mixture for cooling at high power. These attributes reduce fuel usage, increasing range or payload.
Proper drone cooling is essential for long-term drone endurance. Overheating and subsequent engine failure is the most common cause of drone failure.
Hydrogen fuel cells, using hydrogen power, may be able to extend the endurance of small UAVs, up to several hours.
Micro air vehicles endurance is so far best achieved with flapping-wing UAVs, followed by planes and multirotors standing last, due to lower Reynolds number.
Solar-electric UAVs, a concept originally championed by the AstroFlight Sunrise in 1974, have achieved flight times of several weeks.
Solar-powered atmospheric satellites ("atmosats") designed for operating at altitudes exceeding 20 km (12 miles, or 60,000 feet) for as long as five years could potentially perform duties more economically and with more versatility than low Earth orbit satellites. Likely applications include weather drones for Weather reconnaissance, weather monitoring, disaster recovery, Earth imaging and communications.
Electric UAVs powered by microwave power transmission or laser power beaming are other potential endurance solutions.
Another application for a high endurance UAV would be to "stare" at a battlefield for a long interval (ARGUS-IS, Gorgon Stare, Integrated Sensor Is Structure) to record events that could then be played backwards to track battlefield activities.
Reliability
Reliability improvements target all aspects of UAV systems, using Resilience (engineering and construction), resilience engineering and fault tolerance techniques.
Individual reliability covers robustness of flight controllers, to ensure safety without excessive redundancy to minimize cost and weight. Besides, dynamic assessment of flight envelope allows damage-resilient UAVs, using Nonlinear system, non-linear analysis with ad hoc designed loops or neural networks. UAV software liability is bending toward the design and certifications of avionics software, crewed avionics software.
Swarm resilience involves maintaining operational capabilities and reconfiguring tasks given unit failures.
Applications
In recent years, autonomous drones have begun to transform various application areas as they can fly beyond visual line of sight (BVLOS) while maximizing production, reducing costs and risks, ensuring site safety, security and regulatory compliance, and protecting the human workforce in times of a pandemic. They can also be used for consumer-related missions like package delivery, as demonstrated by Amazon Prime Air, and critical deliveries of health supplies.
There are numerous civilian, commercial, military, and aerospace applications for UAVs.
These include:
;General: Recreation, Disaster relief, Archaeology, archeology, conservation of Conservation biology, biodiversity and Habitat conservation, habitat, law enforcement, crime, and terrorism.
;Commercial: Surveillance aircraft, Aerial surveillance, filmmaking,
journalism, Scientific method, scientific research, surveying, Freight transport, cargo transport, mining, manufacturing, Forestry, Photovoltaic power station, solar farming, Thermal power station, thermal energy, ports and agriculture.
Warfare
![Bayraktar TB2 of UAF, 2020, 09](https://upload.wikimedia.org/wikipedia/commons/a/a1/Bayraktar_TB2_of_UAF%2C_2020%2C_09.jpg)
As of 2020, seventeen countries have armed UAVs, and more than 100 countries use UAVs in a military capacity. The global military UAV market is dominated by companies based in the United States, Turkey,
China, Israel and Iran.
By sale numbers, the US held over 60% military-market share in 2017. Top military UAV manufactures are including General Atomics, Lockheed Martin, Northrop Grumman, Boeing, Baykar,
Turkish Aerospace Industries, TAI, Iran Aviation Industries Organization, IAIO, China Aerospace Science and Technology Corporation, CASC and Chengdu Aircraft Industry Group, CAIG.
China has established and expanded its presence in military UAV market
since 2010. Turkey also established and expanded its presence in military UAV market.
Of the 18 countries that are known to have received military drones between 2010 to 2019, the top 12 all purchased their drones from China.
According to a report of 2015, Israeli companies mainly focus on small surveillance UAV systems and by quantity of drones, Israel exported 60.7% (2014) of UAV on the market while the United States export 23.9% (2014).
Between 2010 and 2014, there were 439 drones exchanged compared to 322 in the five years previous to that, among these only small fraction of overall trade – just 11 (2.5%) of the 439 are armed drones.
The US alone operated over 9,000 military UAVs in 2014; among them more than 7000 are AeroVironment RQ-11 Raven, RQ-11 Raven miniature UAVs. General Atomics is the dominant manufacturer with the Global Hawk and Predator/Mariner systems product-line.
For intelligence and reconnaissance missions, the inherent stealth of Micro air vehicle, micro UAV flapping-wing
ornithopter
An ornithopter (from Greek ''ornis, ornith-'' "bird" and ''pteron'' "wing") is an aircraft that flies by flapping its wings. Designers sought to imitate the flapping-wing flight of birds, bats, and insects. Though machines may differ in form, th ...
s, imitating birds or insects, offers potential for covert surveillance and makes them difficult targets to bring down.
UAVs are used for
reconnaissance
In military operations, reconnaissance or scouting is the exploration of an area by military forces to obtain information about enemy forces, terrain, and other activities.
Examples of reconnaissance include patrolling by troops (skirmisher ...
, Offensive (military), attack, demining, and target practice.
Civil
![Wing delivery Vuosaari 3](https://upload.wikimedia.org/wikipedia/commons/2/23/Wing_delivery_Vuosaari_3.jpg)
The civilian (commercial and general) drone market is dominated by Chinese companies. Chinese drone manufacturer DJI (company), DJI alone had 74% of the civil market share in 2018, with no other company accounting for more than 5%, and with $11 billion forecast global sales in 2020. Following increased scrutiny of its activities, the US Interior Department grounded its fleet of DJI drones in 2020, while the Justice Department prohibited the use of federal funds for the purchase of DJI and other foreign made UAVs. DJI is followed by Chinese company Yuneec International, Yuneec, US company 3D Robotics and French company Parrot SA, Parrot with a significant gap in market share. As of May 2021, 873,576 UAVs have been registered with the US FAA, of which 42% are categorized as commercial drones and 58% as recreational drones. 2018 NPD point to consumers increasingly purchasing drones with more advanced features with 33 percent growth in both the $500+ and $1000+ market segments.
The civil UAV market is relatively new compared to the military one. Companies are emerging in both developed and developing nations at the same time. Many early stage startups have received support and funding from investors as is the case in the United States and by government agencies as is the case in India. Some universities offer research and training programs or degrees. Private entities also provide online and in-person training programs for both recreational and commercial UAV use.
Consumer drones are also widely used by military organizations worldwide because of the cost-effective nature of consumer product. In 2018, Israeli military started to use DJI (company), DJI Mavic (UAV), Mavic and Matrice series of UAV for light reconnaissance mission since the civil drones are easier to use and have higher reliability. DJI drones is also the most widely used commercial unmanned aerial system that the US Army has employed. DJI surveillance drones have also been used by Chinese police in Xinjiang since 2017.
The global UAV market will reach US$21.47 billion, with the Indian market touching the US$885.7 million mark, by 2021.
Lighted drones are beginning to be used in nighttime Drone display, displays for artistic and advertising purposes.
Aerial photography
Drones are ideally suited to capturing aerial shots in photography and cinematography, and are widely used for this purpose.
Small drones avoid the need for precise coordination between pilot and cameraman, with the same person taking on both roles. However, big drones with professional cine cameras, there is usually a drone pilot and a camera operator who controls camera angle and lens. For example, the AERIGON cinema drone which is used in film production in big blockbuster movies is operated by 2 people. Drones provide access to dangerous, remote or otherwise inaccessible sites.
Agriculture, forestry and environmental studies
As global demand for food production grows exponentially, resources are depleted, farmland is reduced, and agricultural labor is increasingly in short supply, there is an urgent need for more convenient and smarter agricultural solutions than traditional methods, and the agricultural drone and robotics industry is expected to make progress. Agricultural drones have been used in areas such as Africa to help build sustainable agriculture.
The use of UAVs is also being investigated to help detect and fight wildfires, whether through observation or launching pyrotechnic devices to start Controlled burn, backfires.
UAVs are also now widely used to survey wildlife such as nesting seabirds, seals and even wombat burrows
Law enforcement
Police can use drones for applications such as search and rescue and traffic monitoring.
Safety and security
Threats
Nuisance
UAVs can threaten airspace security in numerous ways, including unintentional collisions or other interference with other aircraft, deliberate attacks or by distracting pilots or flight controllers. The first incident of a drone-airplane collision occurred in mid-October 2017 in Quebec City, Canada. The first recorded instance of a drone collision with a hot air balloon occurred on 10 August 2018 in Driggs, Idaho, United States; although there was no significant damage to the balloon nor any injuries to its 3 occupants, the balloon pilot reported the incident to the National Transportation Safety Board, stating that "I hope this incident helps create a conversation of respect for nature, the airspace, and rules and regulations". Unauthorized UAV flights into or near major airports have prompted extended shutdowns of commercial flights.
Drones caused Gatwick Airport drone incident, significant disruption at Gatwick Airport during December 2018, needing the deployment of the British Army.
In the United States, flying close to a wildfire is punishable by a maximum $25,000 fine. Nonetheless, in 2014 and 2015, firefighting air support in California was hindered on several occasions, including at the Lake Fire
and the North Fire. In response, California legislators introduced a bill that would allow firefighters to disable UAVs which invaded restricted airspace. The FAA later required registration of most UAVs.
Security vulnerabilities
By 2017, drones were being used to drop contraband into prisons.
The interest in UAVs cyber security has been raised greatly after the Predator UAV video stream hijacking incident in 2009, where Islamic militants used cheap, off-the-shelf equipment to stream video feeds from a UAV. Another risk is the possibility of hijacking or jamming a UAV in flight. Several security researchers have made public some vulnerabilities in commercial UAVs, in some cases even providing full source code or tools to reproduce their attacks. At a workshop on UAVs and privacy in October 2016, researchers from the Federal Trade Commission showed they were able to hack into three different consumer
quadcopter
A quadcopter or quadrotor is a type of helicopter with four Helicopter rotor, rotors.
Although quadrotor helicopters and convertiplanes have long been flown experimentally, the configuration remained a curiosity until the arrival of the moder ...
s and noted that UAV manufacturers can make their UAVs more secure by the basic security measures of encrypting the Wi-Fi signal and adding password protection.
Aggression
UAVs could be loaded with dangerous payloads, and crashed into vulnerable targets. Payloads could include explosives, chemical, radiological or biological hazards. UAVs with generally non-lethal payloads could possibly be hacked and put to malicious purposes. Anti-UAV systems are being developed by states to counter this threat. This is, however, proving difficult. As Dr J. Rogers stated in an interview to A&T "There is a big debate out there at the moment about what the best way is to counter these small UAVs, whether they are used by hobbyists causing a bit of a nuisance or in a more sinister manner by a terrorist actor".
Countermeasures
Counter unmanned air system
The malicious use of UAVs has led to the development of Anti-aircraft warfare#Anti-UAV defences, counter unmanned air system (C-UAS) technologies. Automatic tracking and detection of UAVs from commercial cameras have become accurate thanks to the development of deep learning based machine learning algorithms.
It is also possible to automatically identify UAVs across different cameras with different view points and hardware specification with re-identification methods.
Commercial solutions such as the Aaronia AARTOS have been installed on major international airports. Anti-aircraft missile systems such as the Iron Dome are also being enhanced with C-UAS technologies. Utilising a smart UAV swarm to counter one or more hostile UAVs is also proposed.
Regulation
Regulatory bodies around the world are developing unmanned aircraft system traffic management solutions to better integrate UAVs into airspace.
The use of unmanned aerial vehicles is becoming increasingly regulated by the civil aviation authority, civil aviation authorities of individual countries. Regulatory regimes can differ significantly according to drone size and use. The International Civil Aviation Organization, International Civil Aviation Organization (ICAO) began exploring the use of drone technology as far back as 2005, which resulted in a 2011 report. France was among the first countries to set a national framework based on this report and larger aviation bodies such as the Federal Aviation Administration, FAA and the European Aviation Safety Agency, EASA quickly followed suit. In 2021, the FAA published a rule requiring all commercially-used UAVs and all UAVs regardless of intent weighing 250g or more to participate in Remote ID, which makes drone locations, controller locations, and other information public from takeoff to shutdown; this rule has since been challenged in the pending federal lawsuit ''RaceDayQuads v. FAA''.
Export controls
The export of UAVs or technology capable of carrying a 500 kg payload at least 300 km is restricted in many countries by the Missile Technology Control Regime.
See also
* List of unmanned aerial vehicles
* Delivery drone
* Drone in a Box
* International Aerial Robotics Competition
* List of films featuring drones
* Micromechanical Flying Insect
*
ParcAberporth
ParcAberporth is a technology park created on what was Royal Air Force (RAF) station Aberporth, near the village of that name in the county of Ceredigion, Wales. The station was one of two local sites that had been used as a site for a missile ...
* Quadcopter
* Radio-controlled aircraft
* Satellite Sentinel Project
* Tactical Control System
* UAV ground control station
* Unmanned underwater vehicle
References
Citations
Bibliography
*Axe, David. ''Drone War Vietnam.'' Pen & Sword, Military. Great Britain. (2021). ISBN 978 1 52677 026 4
*
*
Further reading
*
* Hill, J., & Rogers, A. (2014). ''hdl:10613/2480, The rise of the drones: From The Great War to Gaza''. ''Vancouver Island University Arts & Humanities Colloquium Series''.
* Rogers, A., & Hill, J. (2014). ''Unmanned: Drone warfare and global security''. Between the Lines.
External links
How Intelligent Drones Are Shaping the Future of Warfare ''Rolling Stone Magazine''
{{DEFAULTSORT:Unmanned Aerial Vehicle
Unmanned aerial vehicles,
Wireless
Avionics
Robotics
Emerging technologies
Articles containing video clips