Contents
Why atmospheric correction is needed?
The objective of atmospheric correction is to determine true surface reflectance values by removing atmospheric effects from satellite images. Atmospheric correction is arguably the most important part of the pre-processing of satellite remotely sensed data and any omission produces erroneous results.
What is Flaash?
FLAASH is a first-principles atmospheric correction tool that corrects wavelengths in the visible through near-infrared and shortwave infrared regions, up to 3 µm. Water vapor and aerosol retrieval are only possible when the image contains bands in appropriate wavelength positions.
How are scientists trying to help coral reefs?
Scientists are also testing new ways to help coral reef ecosystems, such as growing coral in a nursery and then transplanting it to damaged areas. The nursery could help restore damaged reefs using fully formed coral colonies rather than small fragments.
What happens to coral reefs when they are damaged?
Once coral reefs are damaged, they are less able to support the many creatures that inhabit them and the communities near them. When a coral reef supports fewer fish, plants, and animals, it also loses value as a tourist destination.
Which is an example of a coral reef ecosystem?
The Northwest Hawaiian Island coral reefs, which are part of the Papahānaumokuākea National Marine Monument, provide an example of the diversity of life associated with shallow-water reef ecosystems. This area supports more than 7,000 species of fishes, invertebrates, plants, sea turtles, birds, and marine mammals.
How are coral reefs adapted to live in shallow water?
Shallow water, reef-building corals have a symbiotic relationship with photosynthetic algae called zooxanthellae, which live in their tissues. The coral provides a protected environment and the compounds zooxanthellae need for photosynthesis. In return, the algae produce carbohydrates that the coral uses for food, as well as oxygen.