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.