SAN FRANCISCO — Within hours of the March 11 earthquake and tsunami in northeastern Japan, government and commercial satellite operators around the world began tasking spacecraft to obtain detailed imagery of the ravaged region.

Imaging satellite operator GeoEye Inc. entered a series of high-priority orders directing its Ikonos and GeoEye-1 spacecraft to begin capturing images of Japan, Hawaii and the U.S. West Coast, said Chris Tully, senior vice president of sales for GeoEye of Dulles, Va. By March 16, the company had compiled 12,000 square kilometers of Japanese imagery, including vivid depictions of a derailed train near the town of Shinchi and the flooded Sendai airport.

GeoEye distributed the satellite imagery to customers, including Tokyo-based Japan Space Imaging Corp., through a variety of channels including its Web-based service EyeQ. Company officials also provided the data free of charge to the United Nations, Tully said in a March 17 interview.

In many cases, GeoEye released the new images along with archived imagery of the same location to show the impact of the natural disasters. Those before- and-after shots also aid relief organizations trying to figure out routes into and out of the devastated region. “If you are part of the rescue effort and are trying to bring resources to that area, it’s really important to know which roads are out or bridges are gone,” Tully said. “In the case of this earthquake in Japan, there has been massive infrastructure damage all over the country.”

Satellite imagery provider DigitalGlobe also has used historical pictures in conjunction with recent images to show the impact of the earthquake and tsunami. “We put our constellation of three satellites to work collecting imagery as soon as we heard of the disaster,” said Stephen Wood, DigitalGlobe Analysis Center vice president. One day after the earthquake, DigitalGlobe collected imagery of the entire impact zone, spanning 48,000 square kilometers, Wood said in a March 16 e-mail.

Since then, company officials have continued collection efforts. By March 16, DigitalGlobe had amassed images covering 200,000 square kilometers. “Our satellites have witnessed the explosions and failures at nuclear facilities, documented the state of the country’s highways and assessed damage at the main ports and refineries,” Wood said.

Longmont, Colo.-based DigitalGlobe’s customers have access to imagery and analysis within three hours of its collection, Wood said. Imagery also is available publicly through DigitalGlobe’s website, and company officials are providing discounted and donated imagery to the United Nations, the Japanese government, U.S. government agencies and Open Street Maps, a Web-based service that provides free geographic data, Wood said.

Government space agencies also are contributing to the wealth of satellite-based imagery of Japan. Immediately after the earthquake and tsunami, NASA officials drafted plans to obtain additional imagery of Japan and to speed up dissemination of the data captured daily by the space agency’s fleet of Earth observing satellites.

“People in NASA’s Earth science division worked through the weekend to get the [satellite] tasking up, to assemble the images and to get them posted,” NASA Earth Science Division Director Michael Freilich said in a March 15 interview.

One day after the earthquake, NASA had its first opportunity to survey the region using the Moderate Resolution Imaging Spectroradiometer (MODIS), which flies onboard the Aqua and Terra Earth observation satellites. That imagery was processed and disseminated immediately by the MODIS Rapid Response team at NASA’s Goddard Space Flight Center in Greenbelt, Md., Freilich said.

The MODIS imagery was provided to international groups through the U.S. Geological Survey’s Hazards Data Distribution System, which is set up to make satellite and aerial photos available quickly in the wake of disasters. Japanese government and relief agencies have been obtaining satellite imagery free of charge from space agencies around the world since March 11 when the Japan Aerospace  Exploration Agency activated the International Charter on Space and Major Disasters. Through that charter, established in 2000, satellite operators provide imagery free of charge to assist in emergency response as soon as any of the nations that have signed onto the charter request help surveying damage caused by a natural or man-made disaster.

In addition to providing speedy access to MODIS imagery, NASA officials directed instruments onboard Terra and the Earth Observation-1 (EO-1) satellite to target the affected region. On March 13, EO-1’s Hyperion sensor and Advanced Land Imager gathered data as the satellite passed northeastern Japan. On March 14, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on Terra gathered additional high-resolution, multispectral imagery of the region.

The ASTER images, which were processed by U.S. Geological Survey employees at the Earth Resources Observation and Science Center in Sioux Falls, S.D., and available for viewing within hours, “show pretty significant effects of the tsunami and inundation,” Freilich said.

NASA will continue to capture imagery of Japan’s northeast coast with ASTER, MODIS and the Multi-angle Spectrum Imaging Radiometer on Terra and to make that data publicly available, Freilich added.

Debra Werner is a correspondent for SpaceNews based in San Francisco. Debra earned a bachelor’s degree in communications from the University of California, Berkeley, and a master’s degree in Journalism from Northwestern University. She...