Drone / UAS Remote Sensing

Deck scope. Introduction to Remote Sensing through the lens of drones (UAS). Quick tour: what RS is, what a UAS is (distinct from a UAV), sensor types commonly flown, and the processing pipeline.

Definition of remote sensing (course version).

“Remote sensing is the process of detecting and monitoring the physical characteristics of an area by measuring its reflected and emitted radiation at a distance, or collecting images from satellites, aircraft, or Unmanned Aircraft Systems (UAS).”

• Provides the raw data (images) that GIS then uses for maps, spatial analysis, and environmental insight.
• The “at a distance” part is the core idea — we never touch the target.

UAV vs. UAS — know the difference.

• UAV (Unmanned Aerial Vehicle) — the aircraft itself. The quadcopter or fixed-wing platform.
• UAS (Unmanned Aircraft System) — the whole system: aircraft + remote control station + wireless data link + any ancillary ground equipment.
• Part 107 and FAA regulations talk in terms of systems, not just vehicles.

UAS components — the four labeled on the diagram.

• UAV — the aircraft.
• GPS — onboard positioning so the UAV knows where it is.
• Data Link — wireless two-way channel between aircraft and ground control (carries commands up and telemetry/imagery down).
• Antenna — the ground-station side of the data link.

The remote pilot in command (RPIC) sits at the ground station; together with the UAV and the link, these four elements are the minimum UAS.

Drone sensors vary by mission need.

• Some sensors are swappable (gimbal payloads on enterprise drones like DJI Matrice, Freefly Alta, etc.) — you mount whatever fits the job.
• Some are permanently affixed (consumer drones like DJI Mini/Air have fixed RGB cameras).
• Choosing a sensor = choosing which wavelengths, what resolution, what geometry, for what analysis.

Visual slide — no extracted text. Likely a lineup of UAV sensor-mount photos (LiDAR, thermal, multispectral, RGB) introducing the next three slides.

• If you need specifics, see slides 7–9 for the actual sensor types called out.

LiDAR + thermal payload.

• LiDAR (Light Detection and Ranging) — active sensor that fires laser pulses and measures return time → millions of 3-D points per second → dense point clouds and DEMs.
• Thermal camera — long-wave IR (8–14 µm) detects emitted heat. Day or night; sees through smoke.
• Combined mission use: structural inspection, search and rescue, forestry canopy mapping, electrical-substation inspection.

Multispectral + RGB payload.

• Multispectral camera — typically 5 bands (Blue, Green, Red, Red Edge, NIR) for vegetation indices like NDVI, NDRE, and crop-health analytics. Example: MicaSense RedEdge-P, DJI Phantom 4 Multispectral.
• RGB camera — standard visible-light imagery for visual inspection and orthomosaic creation.
• Combined use: precision agriculture, forestry, environmental monitoring.

RGB camera — the baseline payload.

• Three broad bands (Red, Green, Blue) → natural-color photographs.
• Used for orthomosaic generation, visual inspection, progress photos on construction sites, and public-facing deliverables.
• Cheap, ubiquitous, huge market — this is what’s on every consumer drone.

Image / data processing pipeline.

• Drone imagery comes in many flavors — RGB stills, thermal video, multispectral bundles, LiDAR point clouds. Each has its own processing chain.
• Per-image vs orthomosaic: you can process single frames, or stitch hundreds of overlapping frames into an orthomosaic (georeferenced, scale-uniform map).
• LiDAR needs specialized software to build a classified point cloud → DEM/DSM → GIS.
• Platforms commonly used:
  • ERDAS Imagine — classical RS heavyweight.
  • ArcGIS Pro — general-purpose GIS; handles imagery and LiDAR.
  • ArcGIS Drone2Map — specifically for UAV imagery → orthomosaic + DEM.
  • Other photogrammetry apps: Pix4D, Agisoft Metashape, WebODM.