Earth observations can include:
• a birdwatcher’s notes on bird sightings
• numerical measurements taken by a thermometer, wind gauge, ocean buoy, altimeter or seismometer
• photos and radar or sonar images taken from ground or ocean-based instruments
• photos and radar images taken from remote-sensing satellites
• decision-support tools based on processed information, such as maps and models
Just as Earth observations consist of a wide variety of possible elements, they can be applied to a wide variety of possible uses. Some of the specific applications of Earth observations include:
• forecasting weather
• tracking biodiversity and wildlife trends
• measuring land-use change (such as deforestation)
• monitoring and responding to natural disasters, including fires, floods, earthquakes and tsunamis
• managing natural resources, such as energy, freshwater and agriculture
• addressing emerging diseases and other health risks
• predicting, adapting to and mitigating climate change
The quality and quantity of Earth observations continue to mount rapidly. In addition to the ongoing launch of new remote-sensing satellites, increasingly sophisticated in-situ instruments located on the ground, on balloons and airplanes, and in rivers, lakes and oceans, are generating increasingly comprehensive, near-real time observations.
An example of Earth observing sensors are the sensors in the Landsat program.