Visible Infrared Imaging Radiometer Suite
What is VIIRS? The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument collects visible and infrared imagery and global observations of land, atmosphere, cryosphere and oceans.

Suomi NPP is the first satellite mission to address the challenge of acquiring a wide range of land, ocean, and atmospheric measurements for Earth system science while simultaneously preparing to address operational requirements for weather forecasting.

Monitoring the amount of energy emitted and reflected by the planet, it measures both solar energy reflected by the Earth and heat emitted by our planet. This solar and thermal energy are key parts of the Earth’s radiation budget.

National Polar-orbiting Partnership
In January 2012, NASA has renamed its newest Earth-observing satellite, namely NPP (NPOESS Preparatory Project) launched on October 28, 2011, to Suomi NPP (National Polar-orbiting Partnership).

October 28, 2011, 2:48 AM PDT
Suomi NPP/Launch date

Landsat 8 orbits the the Earth in a sun-synchronous, near-polar orbit, at an altitude of 705 km (438 mi), inclined at 98.2 degrees, and completes one Earth orbit every 99 minutes. The satellite has a 16-day repeat cycle with an equatorial crossing time: 10:00 a.m. +/- 15 minutes.

CrIS is a key instrument currently flying on the Suomi NPP and NOAA-20 satellites, and represents a significant enhancement over NOAA’s legacy infrared sounder—the High Resolution Infrared Radiation Sounders (HIRS).

The most precisely calibrated radiometer ever to fly in space, the Clouds and the Earth’s Radiant Energy System (CERES) instrument is measuring emitted and reflected radiative energy from the surface of the Earth and the atmosphere.

A polar orbit is one in which a satellite passes above or nearly above both poles of the body being orbited (usually a planet such as the Earth, but possibly another body such as the Moon or Sun) on each revolution. A satellite in a polar orbit will pass over the equator at a different longitude on each of its orbits.

VIIRS is aboard two satellites: Suomi National Polar-orbiting Partnership (Suomi NPP) and National Oceanic and Atmospheric Administration-20 (NOAA-20).

The MODIS thermal band detects hot spots with a resolution of 1,000 meters per pixel; VIIRS detects hot spots at a resolution of 375 meters per pixel. In other words, VIIRS makes fire observations that are about three times more detailed than MODIS.

Each satellite makes a complete orbit every 99 minutes, completes about 14 full orbits each day, and crosses every point on Earth once every 16 days. The satellite orbits are offset to allow 8-day repeat coverage of any Landsat scene area on the globe.

The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument is aboard the joint NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) satellite and the joint NASA/NOAA NOAA-20 satellite. (Note: Prior to launch, NOAA-20 was known as the Joint Polar Satellite System, or JPSS-1, satellite.)

The Visible Infrared Imaging Radiometer Suite (VIIRS) is the largest instrument aboard of Suomi-NPP (National Polar-Orbiting Operational Environmental Satellite System ( NPOESS) Preparatory Project). It collects radiometric imagery in visible and infrared wavelengths of the land, atmosphere, ice, and ocean.

NPP serves as a bridge mission between NASA’s EOS (Earth Observing System) series of satellites and the next-generation JPSS (Joint Polar Satellite System), a NOAA program that will also collect weather and climate data.

Because of this second role, NPP is sometimes referred to as the EOS-NPOESS bridging mission. Three of the mission instruments on NPP are VIIRS (Visible/Infrared Imager and Radiometer Suite), CrIS (Cross-Track Infrared Sounder), and OMPS (Ozone Mapping and Profiler Suite).