GOES satellites (Geostationary Operational Environmental Satellites) are high-altitude weather monitoring and forecasting instruments. They orbit exactly once each day at 35,800 kilometers above Earth’s surface, or 22,300 miles, and provide constant vigil for the atmospheric “triggers” for severe weather conditions such as tornadoes, flash floods, hailstorms and hurricanes.
Unlike the International Space Station, which circles the planet about 15 times each day, geostationary satellites orbit at an altitude that allows them to remain positioned over one geographic area so they can provide continuous coverage over time. This allows them to monitor large sectors of the Earth’s surface and maintain a high-fidelity image of it.
The GOES satellites have a number of different instruments on board, which are used to monitor Earth’s atmosphere. They collect data from the atmosphere by detecting two types of radiation: electromagnetic and thermal infrared. Electromagnetic radiation is detected by instruments that are sensitive to certain wavelengths of the radio waves that are produced when a satellite passes in front of the Sun.
Solar radiation is reflected off of cloud tops and Earth’s surface, which gives meteorologists information that can help them predict thunderstorms and other weather events. The GOES satellites also gather solar irradiance information, which is useful in monitoring the upper atmosphere to see whether there are any flares or other potential hazards that could disrupt communications and reduce navigational accuracy.
Temperature of the Earth’s surface
The temperature of the Earth is measured using a thermometer that is mounted on a GOES satellite and sends readings to the GOES control center. The GOES satellites send this data to the National Oceanic and Atmospheric Administration (NOAA) where it is processed and distributed for use by meteorologists worldwide.
Temperature of the atmosphere is a very important factor in making accurate weather forecasts. GOES satellites send a high-resolution, real-time thermometer to the NOAA National Center for Environmental Prediction (NCEP) in Silver Spring, Maryland. The thermometer data is used to calculate wind speed and direction and temperature for the local area.
The GOES satellites are also equipped with sensors that detect thermal infrared radiation from the Sun. This type of radiation is absorbed by oxygen, carbon dioxide and other gases in the atmosphere. During cloudy weather, this radiation is absorbed more easily than during sunny days. This means that GOES satellites can view cloud tops and water vapor more closely than they can during clear weather.
Visible Light Imaging
GOES satellites also collect data on the amount of sunlight that is reflected off of the cloud tops and Earth’s surface. This is the same radiation that you need to take regular photographs, so it is easy to recognize clouds and other weather features in the GOES images. Snow, ice and light-colored sand reflect the most sunlight, so they show up brightest in visible light images.
GOES satellites send their imagery to the National Oceanic and Atmospheric Agency (NOAA) through the Satellite Operations Control Center in Suitland, Maryland. The satellites are controlled by NOAA meteorologists who use the information to develop daily weather forecasts for the United States and other countries. GOES satellites are also used to provide real-time mapping of lightning activity.