The National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project, or NPP, was launched on 28 October 2011 to collect and distribute remotely-sensed land, ocean, and atmospheric observations for the meteorological, oceanographic, terrestrial and global climate change communities. It aims to provide data continuity of these measurements from existing Earth-observing missions such as Aqua, Terra and Aura. The NPP satellite is the first in a series designed to provide critical data to improve short-term weather forecasts and increase understanding of long-term climate change.
On 24 January 2012 at the annual meeting of the American Meteorological Society in New Orleans, NASA has renamed its newest Earth-observing satellite in honor of the late Verner E. Suomi, a meteorologist at the University of Wisconsin who is recognized widely as "the father of satellite meteorology." The NPOESS Preparatory Project (NPP) then became the Suomi National Polar-orbiting Partnership satellite, or Suomi NPP (S-NPP).
S-NPP is a pilot mission for the Joint Polar Satellite System (JPSS), which is the next generation polar-orbiting operational environmental satellite system for the USA. Onboard the S-NPP satellite, there are five state-of-the-art instruments/sensors.
The JPSS-1 (NOAA-20) is the second mission in the JPSS series, which is scheduled to launch in the fourth quarter of 2017. For the rest of JPSS series, their schedules are also planned and can be found at the NOAA Launch-Schedule webpage.
VIIRS is the largest instrument onboard NPP, weighing in at 556 pounds (252 kilograms). Its data, collected from 22 channels across the electromagnetic spectrum, will be used to observe the Earth’s surface, including fires, ice, ocean color, vegetation, clouds, and land and SSTs.
The VIIRS instrument is a whiskbroom scanning radiometer with a field of regard of 112.56 degree in the cross-track direction. At a nominal altitude of 824 km, the swath width is 3060 km, providing full daily coverage both in the day and night side of the Earth. VIIRS's 22 spectral bands cover the spectrum between 0.412 µm and 12.01 µm, including 16 moderate resolution bands (M-bands) with a spatial resolution of 750 m at nadir, 5 imaging resolution bands (I-bands) – 375 m at nadir, and one panchromatic DNB with a 750 m spatial resolution throughout the scan. The M-bands include 11 Reflective Solar Bands (RSB) and 5 Thermal Emissive Bands (TEBs). The I-bands include 3 RSBs and 2 TEBs.
VIIRS provides capabilities to produce higher resolution and more accurate SST measurements than currently available from the heritage AVHRR instrument on POES, as well as provide an operational capability for ocean-color observations and a variety of derived ocean-color datasets. SST is one of the key VIIRS ocean datasets and is included in the GHRSST project.