![The sensors aboard Landsat 8 were designed to have higher sensitivity to brightness and color; they use 4,096 values to digitize their signals (12-bit data) whereas the last-generation sensor on Landsat 7 was slightly less sensitive and used only 256 data values (8-bits) to describe the range of brightness it recorded. Visually, this translates into a smoother, less noisy looking images as can been seen here when comparing these natural color Landsat 7 [left] and Landsat 8 [right] images of the extensive coral reefs on the northern shore of Vanua Levu, Fiji’s second largest island, acquired on September 19, 2002 and May 10, 2015, respectively.](https://landsat.gsfc.nasa.gov/wp-content/uploads/2015/06/Levu_Fiji_L8_sm-1.jpg)
Satellites Enable Coral Reef Science Leap from Darwin to Online
June 17, 2015
With Earth-observing satellite data, scientists can now monitor the health of coral reefs, even in the most remote regions scattered around the globe where it is otherwise difficult to see changes.
