Meteorologists need sensors that are on the ground directly measuring local weather conditions, as well as in orbit high above Earth’s atmosphere observing the “big picture” remotely. The United States has a network of ground stations for measuring surface and upper-air weather conditions at particular locations and times. However, this network leaves gaps in the information about the geographical extent of weather phenomena, their speed and direction of movement, and their duration. Satellite data are also needed to provide a complete and continuous picture of atmospheric conditions. The Geostationary Operational Environmental Satellites (GOES) and supporting data processing centers provide timely environmental information to meteorologists and their audiences alike – graphically displaying the intensity, path, and size of storms. Forecasting the approach of severe storms for 35 years, the GOES are a cornerstone of weather observing and forecasting.
Geostationary satellites rotate with Earth from west to east directly over the equator at an altitude of 35,800 km (22,300 statute miles). Because the satellite orbits in the same direction as Earth turns on its axis and matches the speed of Earth’s rotation at the equator, the satellite always has the same view of the Earth’s surface. The U.S. has two Geostationary Operational Environmental Satellites (GOES) in service, one positioned to view the west coast and the Pacific Ocean and one to view the east coast and the Atlantic. Geostationary satellites are in position to maintain a constant vigil over nearly half the planet.
Geostationary weather satellites work by sensing electromagnetic radiation to indicate the presence of clouds, water vapor, and surface features. Unlike ground-based radar systems and some other types of satellites, these satellites do not send energy waves into the atmosphere and analyze returning signals. Rather, the GOES work by passively sensing energy. The GOES sense visible (reflected sunlight) and infrared (for example, heat energy), from the Earth’s surface, clouds, and atmosphere. The Earth and atmosphere emit infrared energy 24 hours a day, and satellites can sense this energy continuously. In contrast, visible imagery is available only during daylight hours when sunlight is reflected.
The instruments on the GOES that measure electromagnetic energy are called radiometers. GOES carries two types of imagers: One measures the amount of visible light from the sun that Earth’s surface or clouds reflect back into space. The second measures the infrared energy that Earth’s surface and clouds radiate back to space. Because the GOES can sense infrared radiation, they can operate at night.
Most visible light passes right through the atmosphere, but no so much through the clouds. Clouds reflect some of the visible light back into space. How much depends upon the thickness and height of the cloud. Earth’s surface absorbs the visible light energy, gets warmer, and re-radiates the energy as infrared radiation. Clouds also absorb some of the visible light energy, as well as the infrared energy re-radiated from Earth. Satellite sensors are particularly sensitive to those wavelengths of infrared energy re-radiated up through to the atmosphere to space. Scientists can measure the height, temperature, moisture content (and more) of nearly every feature of the Earth’s atmosphere, ocean, and land surface, with and without vegetation.
Communications, transportation, and electrical power systems can be disrupted and damaged by space weather storms. Exposure to radiation can threaten astronauts and commercial air travelers alike, and has affected the evolution of life on Earth. Geomagnetic storms and other space weather phenomena pose a serious threat to all space operations, and can result in total mission failure.
Beginning with GOES-I, the Search and Rescue subsystem has been carried on each of the GOES. Distress signals are broadcast by Emergency Locator Transmitters carried on general aviation aircraft, aboard some marine vessels, and by individuals, such as hikers and climbers. A dedicated transponder on each GOES detects and relays signals to a Search and Rescue Satellite-Aided Tracking (SARSAT) ground station. Through a rescue coordination center, help is dispatched to the aircraft, ship, or individual in distress. SARSAT is an international program, with many satellites making up a world-wide network of emergency beacon transponders. Since 1982, SARSAT has helped to save over 28,000 lives worldwide. Learn more.
GOES-R is the next generation of NOAA geostationary Earth-observing systems. The satellite’s advanced spacecraft and instrument technology will support expanded detection of environmental phenomena, resulting in more timely and accurate forecasts and warnings. » More
GOES-R advanced spacecraft and instrument technology will support expanded detection of environmental phenomena, resulting in more timely and accurate forecasts and warnings. The Advanced Baseline Imager (ABI), a sixteen channel imager with two visible channels, four near-infrared channels, and ten infrared channels, will provide three times more spectral information, four times the spatial resolution, and more than five times faster temporal coverage than the current system. Other advancements over current GOES capabilities include total lightning detection (in-cloud and cloud-to-ground flashes) and mapping from the Geostationary Lightning Mapper (GLM), and increased dynamic range, resolution, and sensitivity in monitoring solar X-ray flux with the Solar UV Imager (SUVI).
GOES-R is a collaborative development and acquisition effort between NASA and NOAA. The GOES-R Program includes two projects: The Flight Project, managed by NASA, and the Ground Segment Project, managed by NOAA.
It is the remote back-up facility from which NOAA will command and control the GOES-R satellites in the event the primary satellite operating locations (NSOF & WCDAS) become disabled. It will include the components, antennas, and ground infrastructure needed to communicate with the GOES-R satellites to control the spacecraft and capture the telemetry and science data from the instruments. This site will be able to perform all of the operational functions in case of a failover scenario at the NSOF and/or the WCDAS ground segment facilities. The RBU is located at the I-79 Technology Park Research Center in Fairmont, West Virginia. » Learn More
GOES-R is engaging users early in the process through Proving Ground and NOAA testbed activities, simulated data sets, scientific and user conferences, and other communication and outreach efforts. » Click here for user training information.
The GOES-R Proving Ground engages the National Weather Service (NWS) in pre-operational demonstrations of select capabilities of GOES-R. This venture facilitates the examination and validation of new ideas, technologies, and products through the Advanced Weather Information Processing System (AWIPS).
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Users must either acquire new systems to receive GRB or upgrade components of their existing GVAR systems. At a minimum, GVAR systems will require new receive antenna hardware, signal demodulation hardware, and computer hardware/software system resources to ingest the extended magnitude of GOES-R GRB data.
GOES-R Rebroadcast is the primary space relay of Level 1b products from GOES-R and will replace the GOES VARiable (GVAR) service. GRB will provide full resolution, calibrated, navigated, near-real-time direct broadcast data. » Learn more about GRB.
Users must either acquire new systems to receive GRB or upgrade components of their existing GVAR systems. At a minimum, GVAR systems will require new receive antenna hardware, signal demodulation hardware, and computer hardware/software system resources to ingest the extended magnitude of GOES-R GRB data. See the GRB Downlink Specifications and GRB Product Users Guide (PUG) documents for more information.
The GRB Simulators allow for on-site testing of user ingest and data handling systems, aka GRB field terminal sites. Each unit simulates GRB downlink functionality by generating Consultative Committee for Space Data Systems (CCSDS) formatted GRB output data based on user-defined scenarios, test patterns, and proxy data files. Four GRB simulators have been designated for loan to borrowers who manufacture GRB receivers and other users interested in testing their receive systems. The objective is to allow borrower access to simulators to verify GRB receive system compatibility with the GRB transmission. Information about requesting a simulator for loan can be found at http://go.usa.gov/WvXY. For a complete list of frequently asked questions about the GRB Simulator, see the GRB Simulator FAQs document.
The National Environmental Satellite, Data and Information Service (NESDIS) GOES fly-out chart, which focuses on mission continuity assuming expected life spans, shows the current plan is for GOES-14 to follow GOES-13 in the GOES-East position and for GOES-R to follow GOES-15 in the GOES-West position: http://www.nesdis.noaa.gov/flyout_schedules.html.
The fly-out chart shows configuration changes occurring in these fiscal years:
- FY15 : GOES-15 still in West, GOES-14 in East
- FY17 : GOES-R in West, GOES-14 still in East
- FY20 : GOES-R still in West, GOES-S in East
The final decision will be based on the health/safety/performance of the GOES constellation, so users should also prepare for contingency scenarios as well. If users wish to plan for all possible orbit position scenarios, then plan for GOES-R Series operations as soon as FY16-17 with the GOES-R satellite or as late as FY17-20 with the GOES-S satellite. Operational users should prepare for the earliest case scenario, but also plan for the latest case scenario. NOAA will update the fly-out charts as soon as any changes occur to the planned orbit locations, but until further notice the posted charts are still accurate.
Additional Notes: The GOES-R series satellites in the West position will be at 137W, not 135W (as today's GOES-West). GRB users will want to check out their systems with data from the Post Launch Product Test (PLPT), when GOES-R is at 89.9W. This should also be a consideration for GRB receiver acquisition and deployment. Being prepared for PLPT requires that a pointable receiving system is ready even sooner than the dates in the fly-out chart. Finally, please see the downlink document for additional information.