Satellite Remote Sensing
Satellites allow scientists to see a large area of the ocean at one time as they orbit Earth. This is called Satellite Remote Sensing. With this technology, scientists gather data on different aspects of ocean conditions such as water temperature, chlorophyll levels (which shows phytoplankton amounts), and oceanic currents. They also use satellites to observe blooms and movements of diatoms or other chlorophyll-containing organisms and can track animals that are tagged with beacons that transmit a variety of information up to the satellite. Satellites provide another important tool for Census research -- the Global Positioning System (GPS). This technology tells researchers their exact geographic position by taking distance measurements from three or more satellites at once (see triangulation). Some satellites orbit in synch with the spin of the Earth and therefore are fixed in a set position called a geo-stationary orbit above one location on the planet's surface. Others are in different orbits, such as over the poles, and take global snapshots as they pass over different parts of the Earth. Satellites are invaluable tools for research and are used, in one way or another, by every Census project.
|An artists rendering of the geostationary oceanographic satellite "Goes3" 22,000 miles above Earth. (NOAA Ocean explorer)|
|A thermal image taken by a geostationary satellite positioned over the western Atlantic. This image denotes (in reddish brown) warmer water moving along with the Gulf Stream current. (NOAA Ocean Explorer)|
|Satellite images showing an algal bloom off of southwestern Florida; water temperature is on the left and chlorophyll, denoting algae abundance, is on the right. (NOAA Ocean Explorer; see full-size image -- 41K)|
Click on the links below to see what Census projects use this technology: