The National Oceanic and Atmospheric Administration (NOAA) operates a constellation of 14 geostationary environmental satellites, known collectively as the GOES system. These spacecraft orbit the Earth in a special “geosynchronous” orbit—meaning they rotate at exactly the same speed as the Earth’s rotation, staying in one fixed position above the equator. They constantly watch the same sector of the Earth’s atmosphere, detecting two different types of electromagnetic radiation that reveal conditions in the atmosphere.
The GOES satellites—formerly called the Polar Orbiting Environmental Satellites, or POES—have served as an essential element of NOAA’s weather forecasting system for decades. In a typical day, a GOES satellite will transmit data as often as every 30 seconds for the entire hemisphere it covers—a remarkably rapid pace of information for such an important tool.
GOES’s ability to monitor the same region of the Earth continuously is vital for monitoring atmospheric phenomena, such as severe storms, cyclones, fires and volcanic eruptions. Using a variety of sensors, GOES detects visible light and invisible infrared radiation to provide detailed images of clouds and the atmosphere. In addition, it sounds the atmosphere to determine its vertical thermal and water vapor structures, which helps meteorologists understand the origins of these dangerous events.
Each GOES satellite contains two main instruments, which are the most important for monitoring conditions in the atmosphere. The first of these, called the Advanced Baseline Imager (ABI), is a state-of-the-art 16-band radiometer that measures electromagnetic energy in the visible, near-infrared and infrared regions of the spectrum. Its spectral, spatial and temporal resolutions are orders of magnitude superior to the current GOES fleet.
A second instrument, called the Geostationary Lightning Mapper (GLM), will complement the ABI in observing lightning activity at storm-scale spatial resolutions across a broad geographic area of overlapping coverage. This will significantly enhance the existing lightning and thunderstorm climatology originally established by the GOES-13/GOES-15 system and help improve weather forecasting in regions where GOES is currently unable to adequately observe the phenomena (Christian et al., 2012).
The GOES-R series, which launched on November 19, 2016, will maintain the two-satellite system that has been in place since GOES-9. The GOES-R series will be located at 75 degrees West longitude, which is the location of the current GOES-13, and at 135 degrees West longitude, which is the location for GOES-15.
The GOES-R series is expected to have an operational lifetime through December 2036. The GOES-R satellites have a two-satellite configuration with an on-orbit spare.