This color composite radar image of the volcanic eruption of Alaska's Mount Redoubt was created from three high-resolution acquisitions recorded by Astrium/Infoterra's satellite TerraSAR-X. Unlike optical satellites, radar can penetrate through thick foliage, clouds, or, in this case, ash to detect changes to the surface. This image was acquired in 2009—the same year the U.S. government lifted its 3-meter resolution restriction on commercial radar satellites. No such restriction existed in Canada, Germany, and Italy—all of which now have high-resolution commercial radar satellites in orbit.
Editor's Note: This story has been edited from the print version as a result of a conversation I had during Tech Day of USGIF's Community Week in June. This individual expressed her concern about the original conclusion, making a valid argument that, in the context of commercial imagery and the globalization of the marketplace for such imagery, the companies that provide these products and services are international – they employ citizens of many countries, they are licensed to operate in many countries, and they pay taxes in many countries.
– Brad Causey