Since their debut, the Geostationary Operational Environmental Satellites (GOES) have been revolutionizing weather forecasting and the broader field of Earth observation. NOAA engineers and scientists are now preparing for the next generation of GOES satellites, which will provide additional information to support the nation’s growing needs for disaster preparedness, climate monitoring and environmental science.

The GOES satellites orbit 22,236 miles above Earth at a speed equal to the planet’s rotation, maintaining a fixed position above a particular geographic region of the Earth at all times. On board, a suite of state-of-the-art Earth and space weather instruments allow scientists to collect and process imagery and data in real time. This data is then sent to National Environmental Satellite and Information Service (NESDIS) facilities for distribution to a wide variety of users, from the National Weather Service to universities and private weather services.

GOES consists of two operational satellites, GOES East and GOES West, which share a common orbit. GOES East monitors the eastern side of North America, while GOES West watches the western side. Each satellite carries a number of sensors that allow it to detect a variety of atmospheric phenomena, including clouds, thunderstorms and severe weather.

In addition to the Earth observation sensors, the GOES system also includes a powerful suite of auxiliary instruments that monitor solar activity and space weather events. The GOES Imager, for example, can observe the Sun’s coronal mass ejections, which can cause power grid disruptions and affect communications systems on Earth. Similarly, the GOES Sounder can detect lightning and the magnetometer can measure plasma particles in Earth’s atmosphere and at high altitudes in the solar wind.

These ancillary sensors are augmented by the satellite-to-ground communications link that relays data from remote Automatic Data Collection Platforms (DCPs) on Earth’s surface. The onboard DCS (Data Collection System) collects, processes and transmits environmental data transmitted from the DCPs via narrow-band WEFAX transmissions to the GOES system from a small ground segment of receiving stations that are in radio view of the satellite.

Data transmission from the DCPs to GOES occurs over a network of a series of 200 channels, called slots, that are available at various times during a day. Each slot is assigned a DCP ID, which allows the DCS to identify and respond to data requests from the DCPs. The GOES DAPS (Goes DCS Automated Processing System) then sends the appropriate data to a selected receiver on Earth. The DAPS is capable of both sending random requests to all channels and interrogating specific DCPs at designated intervals during the day.