VIIRS meaning in General ?

The Visible Infrared Imaging Radiometer Suite (VIIRS) is a sensor designed and manufactured by the Raytheon Company on board the polar-orbiting Suomi National Polar-orbiting Partnership (Suomi NPP) and NOAA-20 weather satellite. VIIRS is one of five key instruments onboard Suomi NPP, launched on October 28, 2011. VIIRS is a whiskbroom scanner radiometer that collects imagery and radiometric measurements of the land, atmosphere, cryosphere, and oceans in the visible and infrared bands of the electromagnetic spectrum.

VIIRS is capable of generating two data processing streams that result in two different sets of land products, with global coverage every 14 hours. One is produced by NOAA, and provides operational data for use by the National Weather Service. These are known as environmental data records (EDRs). The other stream is from NASA, and is intended to contribute to the larger scientific community. These are known as Earth System Data Records (ESDRs).

VIIRS's main uses include monitoring and investigating changes and properties in surface vegetation, land cover/use, the hydrologic cycle, and the earth's energy budget over both regional and global scales. The combination of MODIS, AVHRR, and VIIRS data sets will allow for the assessment of how climate change has affected the earth's surface over the past ~20 years.