Glossary

Accelerometer is a device that measures acceleration. Helicopter UAVs typically have 3 orthogonal accelerometers to measure X, Y, and Z axis body accelerations.

Aerial Mapping see Aerial Survey.

Aerial photography is the taking of photographs of the ground from an elevated position. The term usually refers to images taken by a camera that is not supported by a ground-based structure. Cameras may be hand held or mounted, and photographs may be taken by a photographer, triggered remotely or triggered automatically. Platforms for aerial photography include fixed-wing aircraft, helicopters, balloons, blimps and dirigibles, rockets, kites, poles, parachutes, and vehicle mounted poles. Aerial photography differs from air-to-air photography (aircraft serves both as a photo platform and subject).

Aerial Survey is a geomatics method of collecting information by using aerial photography, LiDAR or from remote sensing imagery using other bands of the electromagnetic spectrum, such as infrared, gamma, or ultraviolet. It can also refer to the chart or map made by analyzing a region from the air. This is typically done using aeroplanes, helicopters, or UAVs such as the Vapor Unmanned Aircraft System.

Aerodynamic force is the force created by a propeller or a jet engine is called thrust and it is also an aerodynamic force (as it also acts on the surrounding air). The aerodynamic force on a powered airplane is commonly resolved into three components: thrust, lift and drag.

Aerospace engineering is the primary branch of engineering concerned with the design, construction, and science of aircraft and spacecraft. It is divided into two major and overlapping branches: aeronautical engineering and astronautical engineering. The former deals with craft that stay within Earth's atmosphere, and the latter with craft that operate outside it.

Air traffic control (ATC) is a service provided by ground-based controllers who direct aircraft on the ground and in the air. The primary purpose of ATC systems worldwide is to separate aircraft to prevent collisions, to organize and expedite the flow of traffic, and to provide information and other support for pilots when able.

Airborne inspection is an inspection or exploration of an area. Applications include oil pipeline, agriculture, mining, law enforcement, security, and military exercises.

Airborne remote sensing is a downward or sideward looking sensor mounted on an aircraft to obtain images of the earth's surface. Analog aerial photography, videography, and digital photography are commonly used airborne remote sensing.

Airborne search and rescue is a wonderful asset of first response agencies. They are tasked with searching for persons, regardless if the location is water or land. Aircraft are able to cover a fairly large area quickly including search areas inaccessible by ground units. Read more...

Aircraft are vehicles that fly by being supported by the air, or in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.

Airspeed is the speed of an aircraft relative to the air. Among the common conventions for qualifying airspeed are: indicated airspeed (IAS), calibrated airspeed (CAS), true airspeed (TAS), equivalent airspeed (EAS) and density airspeed.

Aviation is the design, development, production, operation, and use of aircraft.

Blade pitch or pitch refers to turning the angle of attack of the blades of propeller or helicopter rotor into or out of the wind to control the production or absorption of power. Wind turbines use this to adjust the rotation speed and the generated power. A propeller of a ship uses this effect to control the ship's speed without changing the rotation of the shaft and to increase the efficiency of streaming fluids.

C band is a name given to certain portions of the electromagnetic spectrum, including wavelengths of microwaves that are used for long-distance radio telecommunications.

Calibrated airspeed (CAS) is the indicated airspeed of an aircraft corrected for position and instrument error. CAS is equal to true airspeed in standard atmosphere at sea level.

Civil aviation is one of two major categories of flying, representing all non-military aviation, both private and commercial. Civil aviation includes two major categories:

Scheduled air transport, including all passenger and cargo flights operating on regularly scheduled routes; and
General aviation (GA), including all other civil flights, private or commercial.

Composite materials, often shortened to composites, are engineered or naturally occurring materials made from two or more constituent materials with significantly different physical or chemical properties which remain separate and distinct within the finished structure.

Controller Synthesis, as opposed to controller tuning, means that the flight dynamics of the helicopter are modeled, the bounds are formulated in terms of performance, stability, and robustness, and then mathematics are used to solve the problem of generating a controller.

Control Theory is an interdisciplinary branch of engineering and mathematics that deals with the behavior of dynamical systems with inputs. The external input of a system is called the reference. When one or more output variables of a system need to follow a certain reference over time, a controller manipulates the inputs to a system to obtain the desired effect on the output of the system.

Differential global positioning system (DGPS) is an enhancement to global positioning systems that provides improved location accuracy, from the 15-meter nominal GPS accuracy to about 10 cm in case of the best implementations. DGPS uses a network of fixed, ground-based reference stations to broadcast the difference between the positions indicated by the satellite systems and the known fixed positions.

Drag (sometimes called air resistance or fluid resistance) refers to forces which act on a solid object in the direction of the relative fluid flow velocity. Unlike other resistive forces, such as dry friction, which is nearly independent of velocity, drag forces depend on velocity. Drag forces always decrease fluid velocity relative to the solid object in the fluid's path.

Drive shaft, propeller shaft (prop shaft), or Cardan shaft is a mechanical component for transmitting torque and rotation, usually used to connect other components of a drive train that cannot be connected directly because of distance or the need to allow for relative movement between them.

Drone is a powered aerial vehicle that does not carry a human operator, uses aerodynamic forces to provide vehicle lift, can fly autonomously or be piloted remotely, can be expendable or recoverable, and can carry payload. Also called unmanned aerial vehicles (UAV) or unmanned aircraft systems (UAS).

Digital single-lens reflex (DSLR) cameras are digital cameras combining the parts of a single-lens reflex camera (SLR) and a digital camera back, replacing the photographic film. Features like live preview, HD video recording with contrast detection autofocus or ergonomic integration like dedicated film speed buttons took further advantage of the digital image sensor.

Electromagnetic Radiation (EM radiation or EMR) is a form of energy emitted and absorbed by charged particles, which exhibits wave-like behavior as it travels through space. EMR has both electric and magnetic field components, which stand in a fixed ratio of intensity to each other, and which oscillate in phase perpendicular to each other and perpendicular to the direction of energy and wave propagation.

Federal Aviation Administration (FAA) is the national aviation authority of the United States. An agency of the United States Department of Transportation, the FAA has authority to regulate and oversee all aspects of civil aviation in the U.S. The Federal Aviation Act of 1958 created the organization under the name "Federal Aviation Agency," and adopted its current name in 1966 when it became a part of the United States Department of Transportation.

The FAA has eight major roles:

Regulating U.S. commercial space transportation
Regulating air navigation facilities' geometry and flight inspection standards
Encouraging and developing civil aeronautics, including new aviation technology
Issuing, suspending, or revoking pilot certificates
Regulating civil aviation to promote safety, especially through local offices called Flight Standards District Offices
Developing and operating a system of air traffic control and navigation for both civil and military aircraft
Researching and developing the National Airspace System and civil aeronautics

Federal enterprise architecture (FEA) is the enterprise architecture of a federal government. It provides a common methodology for information technology (IT) acquisition, use, and disposal in the federal government.

Fixed wing aircraft is an aircraft capable of flight using wings that generate lift due to the vehicle's forward airspeed and the shape of the wings. Fixed-wing aircraft are distinct from rotary-wing aircraft in which the wings form a rotor mounted of a spinning shaft and ornithopters in which the wings are hinged, allowing them to flap in similar manner to a bird.

Flight control system consists of flight control surfaces, the respective cockpit controls, connecting linkages, and the necessary operating mechanisms to control an aircraft's direction in flight. Aircraft engine controls are also considered as flight controls as they change speed.

Flight Dynamics Model (FDM) is a set of math equations used to calculate the physical forces acting on a simulated aircraft, such as thrust, lift, and drag.

Flow velocity, or velocity field, of a fluid is a vector field which is used to mathematically describe the motion of a fluid. The length of the flow velocity vector is the flow speed.

Geomatics (also known as geospatial technology or geomatics engineering) is the discipline of gathering, storing, processing, and delivering geographic information, or spatially referenced information.

Geospatial analysis is an approach to applying statistical analysis and other informational techniques to data which has a geographical or geospatial aspect. Such analysis would typically employ software capable of geospatial representation and processing, and apply analytical methods to terrestrial or geographic datasets, including the use of geographic information systems and geomatics. Geospatial analysis was developed for problems in the environmental and life sciences, in particular ecology, geology and epidemiology. It has extended to almost all industries including defense, intelligence, utilities, natural resources (e.g., oil and gas, forestry), social sciences, medicine and public safety (e.g., emergency management, law enforcement).

Gimbal is a pivoted support that allows the rotation of an object about a single axis. A set of three gimbals, one mounted on the other with orthogonal pivot axes, may be used to allow an object mounted on the innermost gimbal to remain independent of the rotation of its support.

Ground control station (GCS) is a land- or sea-based control center that provides the facilities for human control of unmanned vehicles in the air or in space. A GCS could be used to control unmanned aerial vehicles or rockets within or above the atmosphere.

Gyroscope is a device for measuring or maintaining orientation based on the principles of angular momentum. Mechanically, a gyroscope is a spinning wheel or disk in which the axle is free to assume any orientation. Although this orientation does not remain fixed, it changes in response to an external torque much less and in a different direction than it would without the large angular momentum associated with the disk's high rate of spin and moment of inertia. Since external torque is minimized by mounting the device in gimbals, its orientation remains nearly fixed, regardless of any motion of the platform on which it is mounted. With the advent of MEMS Gyros, all moving parts are replaced by machined silicone proof masses that can detect and measure angular rates. MEMS gyros have reduced the cost of gyros substantially over the past 20 years.

H_∞ (i.e. "H-infinity") methods are used in control theory to synthesize controllers achieving robust performance or stabilization. To use H∞ methods, a control designer expresses the control problem as a mathematical optimization problem and then finds the controller that solves this. H∞ techniques have the advantage over classical control techniques in that they are readily applicable to problems involving multivariable systems with cross-coupling between channels; disadvantages of H∞ techniques include the level of mathematical understanding needed to apply them successfully and the need for a reasonably good model of the system to be controlled. Problem formulation is important, since any controller synthesized will only be 'optimal' in the formulated sense: optimizing the wrong thing often makes things worse rather than better.

Helicopter (informally called "chopper" or "helo") is a type of rotorcraft in which lift and thrust are supplied by engine-driven rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward, and laterally. These attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft would usually not be able to take off or land. The capability to efficiently hover for extended periods of time allows a helicopter to accomplish tasks that fixed-wing aircraft and other forms of vertical takeoff and landing aircraft cannot perform.

Helicopter rotor is a type of fan that is used to generate both the aerodynamic lift force that supports the weight of the helicopter, and thrust which counteracts aerodynamic drag in forward flight. Each main rotor is mounted on a vertical mast over the top of the helicopter, as opposed to a helicopter tail rotor, which is connected through a combination of drive shaft(s) and gearboxes along the tail boom. A helicopter's rotor is generally made up of two or more rotor blades. The blade pitch is typically controlled by a swashplate connected to the helicopter flight controls. Rotors are sometimes referred to as rotary wings, as they are the wings (as well as propellers) of a rotary-wing aircraft.

Hover is the process by which an object is suspended by a physical force against gravity in a stable position without solid physical contact.

Image sensor is a device that converts an optical image into an electronic signal. It is used mostly in digital cameras, camera modules and other imaging devices.

Infrared camera is a device that forms an image using infrared radiation, similar to a common camera that forms an image using visible light. Instead of the 450-750 nanometer range of the visible light camera, infrared cameras operate in wavelengths as long as 14,000 nm (14 µm).

Iridium satellite constellation is a large group of satellites providing voice and data coverage to satellite phones, pagers and integrated transceivers over earth's entire surface. Iridium Communications Inc. owns and operates the constellation and sells equipment and access to its services. The constellation consists of 66 active satellites in orbit, and additional spare satellites to serve in case of failure. The number of satellites projected in the early stages of planning was 77, the atomic number of iridium, evoking the metaphor of 77 electrons orbiting the nucleus.

L band, as defined by NATO, is the frequency band between 40 and 60 GHz (5-7.5 mm)

LIDAR (Light Detection And Ranging, also LADAR) is an optical remote sensing technology that can measure the distance to, or other properties of a target by illuminating the target with light, often using pulses from a laser. LIDAR technology has applications in geomatics, archaeology, geography, geology, geomorphology, seimology, forestry, remote sensing, laser swath mapping (ALSM), laser altimetry and LIDAR contour mapping. The acronym LADAR (Laser Detection and Ranging) is often used in military contexts.

Lift is the component of surface force exerted by a fluid flowing past the surface of a body which is perpendicular to the oncoming flow direction. It contrasts with the drag force, which is the component of the surface force parallel to the flow direction. If the fluid is air, the force is called an aerodynamic force.

Magnetometer is a measuring instrument used to measure the strength or direction of magnetic fields.

Mechanical engineering is a discipline of engineering that applies the principles of physics and materials science for analysis, design, manufacturing, and maintenance of mechanical systems. It is the branch of engineering that involves the production and use of heat and mechanical power for the design, production, and operation of machines and tools. It is one of the oldest and broadest engineering disciplines

Microelectromechanical systems (MEMS) is the technology of very small devices; it merges at the nano-scale into nanoelectromechanical systems (NEMS) and nanotechnology. MEMS are also referred to as micromachines (in Japan), or micro systems technology – MST (in Europe).

Nadir is the direction pointing directly below a particular location; that is, it is one of two vertical directions at a specified location, orthogonal to a horizontal flat surface there. Since the concept of being below is itself somewhat vague, scientists define the nadir in more rigorous terms. Specifically, in astronomy, geophysics and related sciences (e.g., meteorology), the nadir at a given point is the local vertical direction pointing in the direction of the force of gravity at that location.

NTSC, named for the National Television System Committee, is the analog television system that is used in most of North America, parts of South America (except Brazil, Argentina, Uruguay, and French Guiana), Myanmar, South Korea, Taiwan, Japan, the Philippines, and some Pacific island nations and territories.

PAL, short for Phase Alternating Line, is an analogue television colour encoding system used in broadcast television systems in many countries

Powertrain or powerplant refers to the group of components that generate power and deliver it to the road surface, water, or air. This includes the engine, transmission, drive shafts, differentials, and the final drive (drive wheels, continuous track as in tanks or tractors, propeller, etc.). Sometimes "powertrain" is used to refer to simply the engine and transmission, including the other components only if they are integral to the transmission.

Propellers or airscrews convert rotary motion from piston engines or turboprops to provide propulsive force. They may be fixed or variable pitch. Early aircraft propellers were carved by hand from solid or laminated wood with later propellers being constructed from metal. The most modern propeller designs use composite materials.

Radio control (often abbreviated to R/C or RC) is the use of radio signals to remotely control a device. The term is used frequently to refer to the control of model vehicles from a hand-held radio transmitter. Industrial, military, and scientific research organizations make use of radio-controlled vehicles as well.

Remotely piloted vehicle (RPV) is a term used by Department of Defense to describe a robotic aircraft flown by a pilot located in a ground control station.

Remote Sensing is the acquisition of information about an object or phenomenon without making physical contact with the object. In modern usage, the term generally refers to the use of aerial sensor technologies to detect and classify objects on Earth (both on the surface, and in the atmosphere and oceans) by means of propagated signals (e.g. electromagnetic radiation emitted from aircraft or satellites).

Rotorcraft or rotary wing aircraft is a heavier-than-air flying machine that uses lift generated by wings, called rotor blades, which revolve around a mast. Several rotor blades mounted to a single mast are referred to as a rotor. The International Civil Aviation Organization (ICAO) defines a rotorcraft as "supported in flight by the reactions of the air on one or more rotors." Rotorcraft generally include those aircraft where one or more rotors are required to provide lift throughout the entire flight, such as helicopters, cyclocopters, autogyros, and gyrodynes. Compound rotorcraft may also include additional thrust engines or propellers and static lifting surfaces.

S band is part of the microwave band of the electromagnetic spectrum. It is defined by an IEEE standard for radio waves with frequencies that range from 2 to 4 GHz, crossing the conventional boundary between UHF and SHF at 3.0 GHz. The S band is used by weather radar, surface ship radar, and some communications satellites, especially those used by NASA to communicate with the Space Shuttle and the International Space Station.

Surface force (denoted f_s) is the force that acts across an internal or external surface element in a material body. Surface force can be decomposed in to two perpendicular components: pressure and stress forces. Pressure force acts normally over an area and stress force acts tangentially over an area.

Tail rotor, or anti-torque rotor, is a smaller rotor mounted so that it rotates vertically or near-vertically at the end of the tail of a traditional single-rotor helicopter. The tail rotor's position and distance from the center of gravity allow it to develop thrust in the same direction as the main rotor's rotation, to counter the torque effect created by the main rotor.

Terminal emulator is a program that emulates a video terminal within some other display architecture. Though typically synonymous with a command line shell or text terminal, the term terminal covers all remote terminals, including graphical interfaces. A terminal emulator inside a graphical user interface is often called a terminal window.

Thrust is a reaction force described quantitatively by Newton's second and third laws. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction on that system. In mechanical engineering, force orthogonal to the main load (such as in parallel helical gears) is referred to as thrust.

Torque is the tendency of a force to rotate an object about an axis, fulcrum, or pivot. Just as a force is a push or a pull, a torque can be thought of as a twist to an object. Mathematically, torque is defined as the cross product of force and the lever-arm distance, which tends to produce rotation.

Turboprop engine is a type of turbine engine that drives an aircraft propeller using a reduction gear.

Unmanned aircraft system (UAS) is the term introduced by the Federal Aviation Administration (FAA) and adopted by the United States Department of Defense (DoD) and the Civil Aviation Authority (CAA - United Kingdom) to replace all previous terms used to describe aircraft without the flight crew onboard. Some of these terms include: unmanned aerial vehicle (UAV), drone, remotely piloted vehicle (RPV), etc. A typical UAS consists of the unmanned aircraft (UA), the control system, the control link, and other related support equipment. For example, the Vapor UAS consists of one air vehicle and one ground control station.

Unmanned aerial vehicle (UAV), commonly known as a drone, is an aircraft without a human pilot on board. Its flight is either controlled autonomously by computers in the vehicle, or under the remote control of a navigator or pilot (called a combat systems officer in the military) on the ground or in another vehicle.

Ultra-high frequency (UHF) designates the ITU radio frequency range of electromagnetic waves between 300 MHz and 3 GHz (3,000 MHz), also known as the decimeter band or decimeter wave as the wavelengths range from one to 10 decimeter; that is 10 centimeters to 1 meter. They are used for television broadcasting, cordless phones, walkie-talkies, satellite communication, and numerous other radio services.

Vector is a specific mathematical structure. It has numerous physical and geometric applications, which result mainly from its ability to represent magnitude and direction simultaneously.

Vector field is an assignment of a vector to each point in a subset of Euclidean space. A vector field in the plane, for instance, can be visualized as a collection of arrows with a given magnitude and direction each attached to a point in the plane.

Vertical takeoff and landing (VTOL) is a system in which an aircraft can take off and land vertically.

3D laser mapping analyzes a real-world environment to collect data on its shape and possibly its appearance (e.g., color). The collected data can then be used to construct digital, three-dimensional models of the surface area.