Introduction to UAS

Center for Geospatial Analytics at North Carolina State University

Corey White adapted from Justyna Jeziorska

Objectives

• Use the proper terminology and understand its meaning
• Describe the elements of a UAS
• Classify different UAS according to their design and characteristics
• Understand the current state of UAS development, including the platforms used for mapping today
• Describe the range of applications UAS are used for

First lecture of the course: the goal is shared vocabulary and a mental model of what a UAS is before the course narrows to mapping. Ask who has flown a drone before and what kind; the class survey usually surfaces a good spread from toy quads to Part 107 pilots, which helps calibrate the rest of the topic.

What is a UAV?

Section opener. Use this beat to ask students what they would call the thing before giving them the terminology.

UAS or UAV? Or maybe a drone?

• UAV = Unmanned Aerial Vehicle - the aircraft itself
• UAS = Unmanned Aircraft System - the aircraft plus everything needed to operate it
• RPA / RPAS = Remotely Piloted Aircraft (System) - ICAO’s preferred term¹
• Drone = the colloquial catch-all, now standard in industry and media

The FAA and this course use UAS because the regulations govern the whole system, not just the airframe. “Drone” carried military stigma in the 2010s and professionals avoided it; that fight is over and the industry itself says drone now. One myth to preempt: “drone” is not an acronym, the usage traces back to 1930s target aircraft named after the male bee.

1. International Civil Aviation Organization (ICAO)

UAS: Unmanned Aircraft System

Unmanned: without a person onboard, operated by automatic or remote control

Aircraft: able to fly

System: the associated elements for safe operation, such as control stations, control links, support equipment, payloads, flight termination systems, and launch and recovery equipment

Consists of three elements:

1. Unmanned Aircraft
2. Control Station
3. Data Link

The pilot, control station, and data link to the UAV

The three-element decomposition matters practically: most field failures are control-station or data-link problems (dead tablet, lost link, interference), not aircraft problems. When the course reaches flight planning, pre-flight checks are organized around exactly these three elements.

What counts as a UAV?

Unmanned Aerial Vehicle (UAV)

• Excludes: missiles, weapons, or exploding warheads,
• Includes: all classes of airplanes, helicopters, airships, and powered-lift aircraft,
• Doesn’t include: traditional balloons, rockets, tethered aircraft, and un-powered gliders.

The definitional edges are worth a beat: a cruise missile flies unmanned but is not a UAV because it is expendable ordnance; a tethered balloon carrying a camera is aerial sensing but not a UAV because it is neither free-flying nor powered. These boundary cases foreshadow the regulatory definitions in Lecture 1B.

What does a UAS look like?

Types and classification of UAS

Section transition into classification. Preview: there is no single official taxonomy; military, civil-airworthiness, and market classifications all coexist, so the next slides show several cuts of the same space.

Different shapes and sizes

Range of UAS platforms from micro air vehicles to large military aircraft

Span the extremes on the figure: from insect-scale micro air vehicles to the Global Hawk with an airliner-class wingspan. Everything this course flies sits in the small-UAS band, under 55 lbs, but the design diversity above and below is useful context for classification.

Different designs

Fixed wing, rotary wing, and hybrid UAS designs

Walk the main design families: fixed wing (efficiency, endurance, area coverage), rotary wing / multirotor (vertical takeoff, hover, ease of use), and hybrids like VTOL fixed wing that take off vertically then cruise on wings. Multirotors dominate small-site mapping; fixed wing and VTOL hybrids win on large-area coverage per battery.

Different classifications

Basis	Example classes
Weight / size	Micro, mini, small (sUAS, under 55 lb), large
Endurance	Minutes (small multirotors) to 24+ hours
Altitude	Low altitude, medium altitude (MALE), high altitude (HALE)
Design / lift	Fixed wing, rotary wing, hybrid VTOL, lighter than air
Propulsion	Electric, combustion, hybrid
Range	Visual line of sight, BVLOS, long range

Key point: the classification axis you pick depends on your question. Regulators classify by weight (55 lb line, 250 g line), mission planners by endurance and range, engineers by propulsion and wing loading. Weight is the axis with legal consequences, which is why it dominates in Lecture 1B.

More about classification in the article: Perspectives on Unmanned Aircraft Classification for Civil Airworthiness Standards

Simplified classifications

In practice, most UAS are grouped by size:

Class	Weight	Typical altitude	Endurance	Examples
Micro	Under 250 g	Under 400 ft	15-30 min	DJI Mini, DJI Neo
Small	Under 25 kg (55 lb)	Under 400 ft	20-90 min	Mavic 3E, WingtraOne
Medium	25-150 kg	Up to ~10,000 ft	Several hours	ScanEagle
Large	Over 150 kg	10,000-60,000 ft	24+ hours	MQ-9 Reaper, Global Hawk

This course: micro & small UAS (sUAS), under 55 lb, flown below 400 ft

The size ladder is the scheme students should retain: the two bottom rows are the regulated civil space (sUAS under Part 107), the top rows are military and research platforms. The 250 g and 55 lb lines carry legal weight, which Lecture 1B picks up. Have students place a familiar aircraft into a row; the highlighted card anchors where everything in this course lives.

How does a UAS work?

System elements

Section transition from what they look like to how the pieces fit together. This is the systems-engineering view that the term “UAS” implies.

Generic Unmanned Aircraft System

• Air vehicle
• Mission planning element
• Command and control element
• Communication link
• Launch and recovery element (for some of them)
• Payload

Map these onto the course: mission planning element is the flight-planning software in Topic 3; payload is the sensor whose imagery feeds Structure from Motion in Topic 2; the communication link constraints shape where you can safely fly. Launch and recovery elements are mostly a fixed-wing concern (catapults, belly landings, parachutes).

Inside the aircraft

Main components of a mapping quadcopter

Orient students on the diagram before the function definitions on the next slide: flight controller and IMU in the body, GNSS antenna up top away from interference, camera on a gimbal at the front, battery as the single heaviest component, radio antennas at the rear. The next slide defines what each part does.

What each component does

Flight controller: the onboard computer running the autopilot

IMU: accelerometers and gyroscopes sensing attitude and motion

GNSS receiver: position and velocity from satellite signals

Motors + ESCs: electronic speed controllers turn commands into thrust

Battery: LiPo packs, typically 20-45 min of flight for small multirotors

Radio links: control, telemetry, and video (2.4 / 5.8 GHz)

Gimbal: stabilizes the camera independently of aircraft motion

This names the parts students will hear about all semester: “the IMU drifted”, “lost link”, “gimbal pitch”. The flight controller fuses IMU and GNSS data hundreds of times per second to keep the aircraft stable; that fusion is also what gets recorded as camera position and orientation for every photo, which is the bridge to the next slide. LiPo handling (storage charge, fire safety) comes up before the first field day.

How does it know where it is?

Positioning quality decides map quality:

Method	How it works	Typical accuracy
Standard GNSS	Satellite positioning alone	1-3 m
RTK (Real-Time Kinematic)	Live corrections from a base station or network	1-3 cm
PPK (Post-Processed Kinematic)	Corrections applied after the flight	1-3 cm
Ground control points (GCPs)	Surveyed targets visible in the imagery	cm-level, with any of the above

Why it matters: the recorded camera position of every photo anchors the photogrammetric reconstruction (Topic 2)

This single spec separates a camera drone from a survey instrument. RTK needs a correction source during flight (local base station or NC’s real-time network); PPK logs raw observations and corrects afterwards, which is more forgiving of radio dropouts. GCPs trade field time for control and remain the accuracy check even on RTK flights. Topic 2 puts numbers on all of this with real datasets.

RTK: base and rover

Both receivers track the same satellites; the base station on a known point broadcasts corrections to the rover. Image: TS Eriksson, CC BY-SA 4.0

Walk the geometry: both receivers see the same satellites, so most error sources (atmosphere, clocks, orbits) are shared and cancel when the base, sitting on a known point, broadcasts corrections. On a mapping drone the “rover” is the aircraft itself. In North Carolina the base can be replaced by the NC Geodetic Survey real-time network over a cell connection.

Levels of autonomy

1. Manual: pilot flies with the sticks, no assistance
2. Stabilized: autopilot holds attitude, altitude, and position (GNSS hover)
3. Waypoint missions: aircraft flies a pre-planned route and triggers the camera automatically
4. Autonomous: obstacle avoidance, terrain following, docked “drone-in-a-box” operations

Mapping flights are level 3: planned in software (Topic 3), flown by the autopilot, supervised by the pilot in command

Students are often surprised that mapping is not stick flying: the pilot’s job on a mapping mission is planning, supervision, and takeover if something goes wrong. Overlap and coverage requirements make hand-flown mapping impractical. Level 4 capabilities are why BVLOS rulemaking matters (Lecture 1B); docked drones flying scheduled missions are the direction commercial monitoring is heading.

Sensors

Overview of UAS sensor payloads

Transition into payloads, the part of the system this course cares most about: for mapping, the aircraft is just a sensor positioning platform. The figure shows the breadth beyond cameras: chemical sniffers, radiation detectors, meteorological probes. Point out that sensor choice drives aircraft choice, not the other way around: payload mass, power draw, and mounting/gimbal requirements are the coupling constraints, which the integration slide will formalize.

UAS sensors for mapping

Sensor	Measures	Mapping products	Cost
RGB camera	Visible light	Orthophotos, DSMs, 3D models	$
Multispectral	Visible + NIR bands	NDVI, vegetation maps	$$
Hyperspectral	100+ narrow bands	Detailed spectral analysis	$$$
Lidar	Active laser returns	Bare-earth DEMs, canopy structure	$$-$$$
Thermal	Longwave infrared	Temperature anomaly maps	$$

This is the shortlist the course actually uses. RGB feeds photogrammetry (Topics 2-4); multispectral supports vegetation indices; lidar gives below-canopy terrain; thermal supports water, wildlife, and infrastructure applications. The following slides take each in turn.

RGB (natural color) cameras

• Most common payload for consumer-grade UAS
• Photo or video mode
• Mapping (orthophoto and DSM generation) possible even with non-photogrammetric cameras
• Variety of cameras, lenses, and mounting systems - some suitable for 3D modeling

“Non-photogrammetric” means consumer cameras without calibrated, stable lens geometry; Structure from Motion self-calibrates well enough that they still produce usable orthophotos and surface models, which is what made UAS mapping cheap. Mechanical vs rolling shutter is the spec worth teaching here: rolling shutter distorts imagery taken in motion and modern mapping drones advertise mechanical/global shutters for that reason.

Multispectral and hyperspectral cameras

• Miniaturization is challenging in terms of optics and sensor calibration
• Weight, cost, data quality have improved; spectral bands, resolution keep improving
• Cameras with NIR band: agriculture and vegetation mapping (for NDVI)
• The more bands the more information, but also higher price of the sensor
  • $$ multispectral - couple thousand
  • $$$ hyperspectral - tens of thousands

Multispectral has gone mainstream: integrated platforms like the DJI Mavic 3 Multispectral bundle RGB plus narrow bands with a sunlight sensor for reflectance calibration, at a price individual labs can afford. Hyperspectral (hundreds of contiguous bands) still costs an order of magnitude more and demands careful radiometric calibration; it stays a research payload.

Active sensors - LiDAR and SAR

• Active sensors can reach below-canopy ground surface
• Trade-offs between performance and size or cost of LiDAR keep shrinking
• LiDAR is now a routine UAS payload thanks to miniaturization
• SAR (Synthetic Aperture Radar) used experimentally, still faces challenges in adaptation to UAS

The figure pair is the pitch: first-return surface vs bare-earth ground under vegetation, which passive photogrammetry cannot deliver. Integrated lidar payloads (DJI Zenmuse L2 class) have made this routine survey equipment. Connect to the photogrammetry-vs-lidar comparison that returns in the terrain-analysis topics.

Thermal imaging

• Used in forest fire monitoring, search and rescue missions, wildlife surveys, and building/solar inspection
• For mapping purposes usually paired with a visible-band camera on the same gimbal (e.g. DJI Mavic 3T class platforms)

Uncooled microbolometers are what fit on small UAS: lower resolution (often 640x512) and radiometric accuracy of a few degrees, so thermal mapping is about patterns and anomalies more than absolute temperature. Flights happen at night or dawn to maximize thermal contrast, which is why the 2021 night-operations rule (Lecture 1B) mattered to this application.

Sensor and platform integration

The optimal combination of carrier (unmanned vehicle) and sensing payload needs to be determined based on:

• Volume, size, and weight specifications
• Specific application requirements
• Mounting: integrated by manufacturer or custom solutions
• The sensors must be adapted to the carrier and vice versa

The market has largely resolved this in favor of manufacturer integration: turnkey platforms with matched sensor, gimbal, and processing pipeline. Custom integration survives at the research edge (novel sensors, larger platforms). Note the regulatory hook: payload weight counts toward the 250 g and 55 lb thresholds discussed next lecture.

The platform landscape today

• Consumer/prosumer multirotors dominate small-site mapping (DJI Mini and Mavic series)
• Dedicated survey platforms: DJI Matrice series, WingtraOne and other VTOL fixed wings, eBee-class flying wings (AgEagle)
• Supply-chain and security policy now shapes procurement: NDAA-compliant / Blue UAS-listed aircraft (Skydio, Freefly, and others) are required for many U.S. government and federally funded operations
• Check program requirements before buying: see drone use in federally funded projects at NC State

Two forces define the current market: DJI’s dominance on capability per dollar, and U.S. policy restricting Chinese-made aircraft in government and federally funded contexts (American Security Drone Act, agency bans, proposed broader restrictions). For students heading into public-sector or funded-research work, “which drone may I use” is now a compliance question before a technical one; the NC State research-security page linked here is the campus authority.

Who uses UAS?

Types of UAS operations

Section transition from hardware to users and applications. The operational categories here get their full regulatory treatment in Lecture 1B; today is just the landscape.

Types of UAS operations

• Public Operations Governmental: agencies and public universities operating under federal statute (COA) or Part 107;

• Civil Operations Non-governmental, must be conducted in accordance with all Federal Aviation Administration (FAA) regulations (Part 107);

• Recreational Operations Flying strictly for fun, under the recreational-flyer exception (49 USC 44809).

Terminology update worth stating aloud: the old “model aircraft” category was repealed in 2018 and replaced by the recreational-flyer exception; older materials and videos still use the old term. Purpose of the flight, not the aircraft, decides the category; the full rules for each are next lecture.

Can I use it?

Regulations, standards, policies, and procedures

Deliberate cliffhanger: the honest answer is “it depends on purpose, place, aircraft, and pilot,” and resolving that is all of Lecture 1B. Today only the orientation layer.

Know before you fly

• “Know Before You Fly” is an educational campaign that provides prospective unmanned aircraft users with the information and guidance they need to fly safely and responsibly.
• Different rules apply to recreational and business users and government entities
• Commercial operations are governed by Part 107, covered in depth next lecture

Know Before You Fly is an industry-FAA outreach partnership; it is a decent student-facing entry point, though faa.gov/uas is the authoritative source. Set expectations: next lecture covers Part 107, the recreational exception, TRUST, and airspace authorization in detail.

What are UAS used for?

Applications section: the goal is breadth, since Assignment 1A asks each student to research one system and its application in depth and present it. Encourage them to note which applications connect to their own research as these slides go by.

Army and government

• Department of Agriculture
• Department of Commerce
• Department of Defence
• Department of Energy
• Department of Homeland Security
• Department of Interior
• Department of Justice
• NASA
• NOAA
• State Universities
• State Law Enforcement

Military Use

Military use drove the technology historically and still drives much R&D funding; the civil agencies on this list operate large mapping and monitoring fleets (Interior and NOAA especially). This is also where the NDAA/Blue UAS procurement constraints from the platform slide bind hardest.

Civilian application fields

Commercial drone industry segments

Big-picture market view: inspection, agriculture, construction, and surveying/mapping are the dominant commercial segments by revenue. Mapping and analytics, this course’s slice, cuts across nearly all of them because most applications ultimately want georeferenced products.

Applications: agriculture and telecommunications

• Agriculture:
  • UAS equipped with fertilizer and pesticide dispersing equipment can be used to spray over large fields;
• Telecommunications:
  • As mobile relay platforms, e.g., in disaster zones for emergency telecommunications

Spray drones are a distinct regulatory world: over 55 lbs, they need exemptions beyond Part 107, and agricultural spraying is one of the fastest-growing segments. The telecom-relay use case reappeared prominently in recent hurricane responses, including in western North Carolina.

Applications: media and traffic monitoring

• News Broadcasting:
  • In providing aerial video feeds for news events;
• Air Traffic Control and Ground Traffic Control:
  • To monitor traffic and accidents over highways and streets, capture violation of traffic rules;

Both examples raise the flight-over-people and privacy questions that Lecture 1B’s operations-over-people categories and best-practices slides address; newsgathering over crowds is exactly the case the category rules were written for. Traffic monitoring by DOTs is now routine, including NCDOT programs.

Applications: mining and coastal monitoring

• Mineral Exploration:
  • In aerial survey, to find minerals in hard-to-reach regions;
  • In existing mines, to map extracted material volumes;
• Coastal Monitoring:
  • Mapping dynamic shorelines and post-storm assessment

Mine volumetrics is a flagship photogrammetry use case: repeat surveys plus DEM differencing gives stockpile and extraction volumes, exactly the change-detection workflow taught later in this course. Coastal monitoring is the local research strength; CGA has flown repeat shoreline surveys on the North Carolina coast.

Remote sensing: environment and emergency response

• Agriculture and Environment:
  • Crop monitoring, vegetation mapping, forest fire monitoring, animal detection;
• Intelligence, Surveillance, and Reconnaissance:
  • Detection of lost persons in difficult-to-access situations, support fire brigades in real-time crisis management, rapid disaster management;

The remote-sensing framing distinguishes these from the service applications: here the product is data and derived maps. Crop monitoring connects to the multispectral/NDVI slide; search and rescue to thermal. Disaster response is a strong thread for this course given recent North Carolina hurricane experience.

Remote sensing: engineering and cultural heritage

• Aerial Monitoring in Engineering:
  • Infrastructure inspections, distributed wind measurement, landslide monitoring;
• Cultural Heritage:
  • Orthophotos of archaeological sites, 3D models of man-made structures;

Infrastructure inspection is the killer commercial app: bridges, towers, and solar farms replace rope teams and lift trucks with a camera in the air. Cultural heritage showcases Structure from Motion 3D reconstruction (Topic 2) on structures rather than terrain; both engineering monitoring cases (landslides especially) are repeat-survey change-detection problems.

Remote sensing: surveying and cadastral mapping

• General surveying, mapping, and photogrammetry, cadastral applications:
  • Cadastral surveying, alternative to traditional surveying, high-precision parcel boundary determination;

This is the course’s home application. The flight-track figure previews Topic 3: systematic overlapping flight lines are what turn a camera drone into a survey instrument. Modern RTK/PPK positioning on survey platforms reaches centimeter-level accuracy, which is what makes cadastral-grade work possible.

Why should you know how to use UAS?

How to obtain spatial data?

UAS between terrestrial survey and satellite platforms in the data-acquisition spectrum

The figure places UAS in the data-acquisition spectrum between terrestrial survey and crewed-aircraft/satellite platforms: UAS win on spatial resolution and revisit flexibility, lose on coverage area. The course’s premise is that this niche, centimeter-resolution mapping on demand, is now accessible to any trained geospatial analyst.

The UAS mapping workflow

How the rest of this course fits together:

flowchart TB
    R["Rules & regulations"] -.-> A
    A["Plan the flight"] --> B["Collect imagery"]
    B --> C["SfM processing"]
    C --> D["GIS analytics"]
    %% D --> E["Object/Change Detection"]

The orientation slide for the whole semester: every later topic is one box in this pipeline. Point out that the arrows run both ways in practice; analysis needs (resolution, accuracy) drive flight planning choices, which is why planning comes after the processing topics have taught what the data must support. The field trip is where the left half becomes real.

Data products you will make

Orthophoto: a georeferenced, distortion-free image map

Surface (DSM) vs terrain (DTM) elevation models

• Point cloud: millions of 3D points from SfM photogrammetry or lidar
• 3D mesh: a continuous textured surface for visualization and measurement

Define the four product types now so Topic 2 lands softly: the orthophoto is the map-accurate image (unlike a raw aerial photo), the DSM includes vegetation and buildings while the DTM is bare earth, and the difference between them is itself an analysis product (canopy height). Point cloud and mesh are the 3D intermediates the rasters are derived from. Every product here comes out of imagery students will collect themselves.

Barriers

• Constantly changing legislation and regulations
• Political and societal acceptance, privacy concerns
• Supply-chain and security restrictions on aircraft procurement

… what do you consider a barrier in UAS development? What obstacles do you see for yourself as a potential UAS user?

Close with the open discussion; typical student answers include cost, battery endurance, training burden, and airspace access, all worth affirming. The three listed barriers each get follow-up in this course: regulations in Lecture 1B, procurement policy from the platform-landscape slide, and societal acceptance in the best-practices discussion. Collect answers on the board; they make a nice callback in the final topic.

Wrap-up

Next lecture: Rules and regulations for UAS operations, when and where you may legally fly

Assignment 1A: UAS systems and applications, pick one system, research it, and present it to the class

Recap the arc: terminology, system elements, classification, sensors, operations, applications. Point students at the assignment page for the full list of required presentation elements and the due date, and remind DE students of the recorded-narration option.