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A great deal can be learned about the planet's surface from far above it. Remote sensing is the science of gathering information about objects or areas from a distance — usually from aircraft or satellites — by detecting the energy reflected from Earth.
A lidar (light detection and ranging) image made with data collected by NOAA's National Geodetic Survey. Credit: NOAA.
Two kinds of sensor
| Passive sensors | Active sensors | |
|---|---|---|
| What they respond to | external stimuli: natural energy reflected or emitted from the Earth's surface | their own signal |
| Example | detecting reflected sunlight, the most common source of radiation they record | a laser system that shines a laser at the surface and times how long the light takes to return |
What it is used for
- Coasts. Monitoring changes in the shoreline, tracking the movement of sediment and mapping coastal features — data used for coastal mapping and preventing erosion.
- Oceans. Monitoring ocean circulation and currents, measuring ocean temperature and wave height, and tracking sea ice — data that helps us understand the ocean and manage its resources.
- Hazards. Tracking hurricanes, earthquakes, erosion and floods — data used to assess a disaster's impact and plan for before and after it strikes.
- Natural resources. Monitoring land use, mapping wetlands and charting wildlife habitat — data used to limit the damage urban growth does to the environment and to decide how best to protect natural resources.
Sources
Based on "What is remote sensing?" from NOAA's National Ocean Service, a work of the United States government in the public domain.
SprogEnglish
Licens: CC0 1.0 (offentligt eje) · Bearbejdet efter oceanservice.noaa.gov
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