Geostationary Operational Environmental Satellites (GOES) have been a major part of the National Weather Service’s weather operations for more than 40 years. They provide continuous imagery and information about the Earth’s weather, including solar activity (space weather).
GOES satellites are in a geosynchronous orbit—an orbital distance from the center of the Earth that remains steady and stationary throughout their flight, allowing them to monitor the surface continuously. Their observation locations are above the equator, making it possible for them to gather weather data as often as every 30 seconds in a hemisphere.
The GOES satellites’ instruments measure electromagnetic radiation emitted by the Earth and reflected from the Earth’s atmosphere, giving scientists valuable information about atmospheric temperature, wind speed, moisture and cloud cover. In addition to measuring the visible light that we see with our eyes, GOES satellites also measure long-wave and short-wave thermal infrared radiation.
Scientists use the longer wavelengths of thermal infrared radiation to identify clouds and water vapor that are very high in the atmosphere. They do this because Earth’s oxygen, carbon dioxide, ozone and methane absorb the longer wavelengths of thermal infrared, while only the shorter wavelengths pass through.
They also measure the temperature of the air on the ground and in the lower atmosphere, where the oxygen, carbon dioxide and ozone can’t absorb the infrared radiation. These measurements enable scientists to determine the height of clouds and the amount of water vapor in the atmosphere and make more accurate weather forecasts.
Currently, there are four operational GOES satellites: GOES-N, GOES-R, GOES-S and GOES-T. The GOES-R series is a four-satellite program that will extend the life of the GOES satellite system through 2036, with the first GOES-R satellite launched on 19 November 2016.
The GOES-R series is being built by Lockheed Martin using the A2100 satellite bus. It will feature the Advanced Baseline Imager (ABI), Extreme Ultraviolet and X-ray Irradiance Sensors (EXIS), Space Environment In-Situ Suite (SEISS) instruments.
These instruments are used to image the Earth’s weather, oceans and environment with 16 different spectral bands in visible light, near-infrared and infrared. They will enable GOES to observe the Earth’s surface in a way that is not possible with the older generation of satellites.
This new series will also include the capability to produce ten-minute full disk imagery, a key requirement for NOAA National Weather Service and Volcanic Ash Advisory Centers. This will allow for more frequent, better-resolution observations and improved aviation safety in hazard areas like the ocean or over mountains.
For example, the 10-minute full disk imaging will help NOAA NWS offices and National Centers track volcanic activity in the Pacific region and ash plumes from eruptions as they rise and fall, thus helping to reduce airplane accidents.
In addition, GOES-R will have the ability to detect and locate hurricanes, tornadoes and other severe weather events that occur in the Atlantic, Gulf of Mexico and Caribbean regions. This will help meteorologists and the public to track these weather events more effectively, and provide timely warnings for potential hazards.