The GOES-11 - 15 Transition

New technology brings higher resolution imagery and more exacting science

When you see images like these during the weather forecast on your local news, you are seeing the work of a NOAA satellite.

Image of GOES-11 (top panel) and GOES-15 (lower panel). The improved spatial resolution for the mid-level water vapor band is evident. Both images are from 21 UTC on December 1, 2011.[click to enlarge]

The National Oceanicand Atmospheric Administration (NOAA) keeps two satellites in geostationary orbit, each in a spot 22,000 miles away from Earth. This allows the satellites, known as Geostationary Operational Environmental Satellites (GOES), to keep watch 24/7 over the Western Hemisphere and parts of the Southern Hemisphere. Positioned at 75 degrees West longitude, GOES-13 (or GOES-East) monitors North and South America and most of the Atlantic Ocean. GOES-11 (or GOES-West), positioned at 135 degrees West longitude, monitored the North America and the Pacific Ocean basin.

As with any aging electronic equipment, GOES-11 needed to be replaced to keep operations running smoothly. GOES-15, NOAA’s newest geostationary satellite, replaced GOES-11 as the operational GOES-West satellite on December 6, 2011. GOES-11 did not re-enter Earth's atmosphere. It was “retired” from service through a final burn from its booster, which moved it approximately 300 km above its current geostationary orbit where it will not interfere with other satellites. In coordination with the National Aeronautics and Space Administration(NASA) and aerospace industry partners, NOAA launched GOES-15 on March 4, 2010. Since then it waited to be called to duty, after its on-orbit engineering and science check-outs.

GOES-15 not only replaced an aging satellite, but also carries newer technology compared to GOES-11. GOES-15 has 4 main instruments, including an Earth imager and sounder, a space environment monitor, and an instrument that takes images of the sun. These instruments provide improved data including finer spatial resolution (8 to 4 km in the 'Water Vapor' band of the imager), better signal-to-noise ratio, stable image navigation and registration, and more images. GOES-15 captures higher resolution images of weather patterns and atmospheric measurements than those provided by earlier satellites. This allows forecasters to pinpoint the location of severe weather with greater accuracy.

As GOES-11 retired, GOES-15 moved westward, and took some pretty amazing images along the way. Shown here are two images from the GOES-15 visible sensor. The first one, taken on September 7, shows the satellite in its storage position over the Central U.S. The bottom image was taken on November 22, as GOES-15 approaches its final position near 135 deg W longitude.[click to enlarge]

The GOES Imager is used for a host of applications, ranging from meteorological and climate to oceanographic and hazards. The Sounder is used to estimate temperature and moisture profiles in the atmosphere. It can also derive information on clouds and certain trace gases such as upper-level ozone. The space environment monitor and solar imager helps watch solar storms that can impact satellites, power grids, communications, navigation, and many other technological systems.

NOAA is already developing its next generation geostationary satellites, known as GOES-R, which will replace the current operational satellites including GOES-15. GOES-R will continue to help improve weather forecasting and environmental monitoring.

When you want to replace an old cell phone, you might purchase a new phone online and receive it at your home, you might travel to a cell phone store to pick-up a new one? What happens when the U.S. needs to replace an aging satellite in space? It can’t go to a “satellite store” to pick-up a new one. It has to plan in advance because it takes many years to build and launch a satellite and get it ready to be used.

NOAA's mission is to understand and predict changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources. Join us on Facebook, Twitter and our other social media channels.

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