Adapted from the article on https://appliedsciences.nasa.gov/join-mission/training/english/arset-fundamentals-remote-sensing
Solar radiation passes through the atmosphere and hits a target surface such as a forest, water, or built up area. Different materials reflect, emit, and absorb at different wavelengths.
- Incident solar radiation: radiation emitted from the sun
- Atmosphere: Some of that radiation interacts with the atmosphere. When a satellite detects this radiation, it can evaluate what might have caused interference in the atmosphere.
- Forests and trees: Vegetation reflects certain wavelengths of solar radiation back to a satellite’s sensors. Changes in the wavelengths reflected can lead to information on any land cover changes that might be occurring.
- Water: Water reflects radiation mostly in the blue-green spectrum. Changes in these reflected wavelengths can provide data on change in water levels, whether or not there is algal growth on the water, and more.
- Grass and crops: Grass, crops and bare soil reflect different types of radiation to a satellite’s sensors.
- Pavement and buildings: Pavement and buildings both reflect different wavelengths of light than natural materials. This allows a satellite to collect data on the amount of development in an area.
- Reflected solar radiation: The satellite sensors detect reflected radiation from the sun.