From imagination to innovation: GeoColor as a flagship of satellite imagery
By Theresa Barosh | Feb. 2025
Since the first pictures of the Blue Marble by Apollo astronauts heading to the moon, humans have been fascinated by photographs of the colorful earth from space. Researchers at NOAA’s Cooperative Institute for Research in the Atmosphere know the importance of color and have worked to make the vibrant satellite imagery that often appears in news outlets possible.
“The value of color transcends beauty — it holds rich information content in a form that is readily relatable to human analysts of complex earth scenes,” said Steve Miller, director of the CIRA and developer of GeoColor. “GeoColor provides a natural entry point for understanding the power [of weather satellites] — conveying the complexity and beauty of our planet’s weather in a simple, intuitive way that everyone can appreciate.”
Today, CIRA’s GeoColor product provides a standard form of imagery used by forecasters, scientists, and media alike when covering all manner of weather and environmental stories. GeoColor produces satellite images that look like full color photos but are not.
How did researchers manage to make full color images with available satellite data?
The work represents the culmination of years of NASA-NOAA collaboration and behind-the-scenes scientific research.
The beginning of the story started in the 1960s. At the time, NASA’s Applications Technology Satellite carried an instrument that could image the colorful earth using red, green and blue channels much like a typical digital camera. Unfortunately, satellites have a limited lifespan. They decay in orbit. They can be hit by space debris. Their instruments experience wear and tear. After 11 years of service, NASA’s Applications Technology Satellite was decommissioned.
Since then, there has not been a U.S. sensor in geostationary orbit, staying consistently above North America, that provided that same capability. Instead, only a single visible channel enabling black and white imagery has been available.
The new generation GOES-R Advanced Baseline Imager that went up on the last set of NOAA geostationary weather satellites almost regained the capability. Then, the instrument had to drop one of the necessary bands, green, in a cost-saving measure. So, currently available geostationary weather satellites over the U.S. only collect information in red and blue bands of visible light.
In a truly innovative fashion, CIRA researchers worked to build out a hybrid green band, providing a capability that would have cost millions of dollars to include on the weather satellite instrument. Behind the scenes, a complex algorithm builds out the green seen in U.S. geostationary satellite imagery.
“[We] developed a ‘synthetic’ [green] based on Japan’s Himawari-8 imager, which contained the necessary information, almost,” said Miller describing an instrument onboard a geostationary satellite above Japan.
CIRA researchers worked together to puzzle out the algorithm. Miller said Himawari’s “green band” wasn’t perfectly green either, but the researchers figured out how to use an additional near-infrared band, onboard U.S. satellite instruments, to impart additional sensitivity to green vegetation — a ‘hybrid’ green approach.
Now, the CIRA-developed hybrid green is also used today by Japan and Europe to enable true color imagery from their “almost green bands” available from instruments on their weather satellites.
CIRA maintains a satellite library for easy access to satellite images of recent events, including GeoColor and other satellite products.