Each day, Earth changes. Some changes, like clouds, are noticeable. Some changes are very subtle, like the color of the ocean or greenness of the grass. But each day the Visible Infrared Imaging Radiometer Suite (VIIRS) sensor on the Suomi NPP satellite is able to document these changes around the world in stunning detail.
This basic capability is not new for satellites. Pseudo-true color composites have been generated for decades. They work just like a television, combining three channels of light, each with red, green and blue information, called RGB color. VIIRS is revolutionary because it combines not just three, but ten different channels, each providing more subtle detail and removing noise from the image like dust, aerosols or the scattering of light that happens over great distances. You can see the difference here.
Not only does VIIRS provide higher definition imagery, it captures this information over the entire globe, with no gaps between its sensor swaths. All combined, the information paints a 53,376 x 26,688 pixel image of Earth. This detail and coverage means one thing: lots of data. In one day, the sensor collects 3.5 terabytes of data (the equivalent of 224 smart phones (16GB)), all of which needs to be processed in near real-time, distributed to users around the world and stored in perpetuity.
Each day, NOAA View will update with the most recent global composite of VIIRS true color imagery.
Each image is assembled by processing 15 orbits of the Suomi NPP satellite over a 24 hour period, and uses techniques to blend the edges of each orbit.
Since the Suomi NPP satellite is in a sun-synchronous afternoon orbit, the middle of each orbit shows a strip of reflected sunlight (called “glint”) over the oceans.
The data for each image can be accesssed via NOAA CLASS.