disaster management

Satellite images guide Haiti relief efforts

ZKI Crisis map (300 dpi)

Satellite assessment of earthquake damage in Port-au-Prince, Haiti on Jan. 13, showing the extent of building damage. Below, NASA’s Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) captured this false-color composite image of the city of Port-au-Prince, Haiti, and the surrounding region on Jan. 27. (Courtesy: NASA/JPL)

U. TEXAS (US)—In the days following the Haiti earthquake, satellite and aerial imagery, along with elevation data, helped first responders distribute aid and medical care and conduct search and rescue missions.

“This is the information that you need to assess risk throughout the region,” says Gordon Wells, program manager and principal investigator for Mid-American Geospatial Information Center (MAGIC). “It gives you a foundation upon which you can develop plans to assist the reentry and recovery of the entire region that has been impacted.”

MAGIC, a repository of remote sensing data drawn from a variety of sources, is based at the Center for Space Research (CSR) at the University of Texas at Austin and has served as one of the main conduits in the flow of information to help emergency operations.

The process of getting information to responders isn’t simply a question of delivering data. Satellite images captured obliquely from space distort the Earth’s topography such that the raw image files from satellites are often inaccurate, limiting their usefulness.


“If you were out in the field and you had a GPS unit to keep track of where you had visited to do a search and clear operation, you could be blocks off in your geo-location with respect to an uncorrected image-map,” Wells says. “We’re refining the geospatial data so that the field teams can use the imagery effectively during their field traverses.”

This process, called geospatial image registration, integrates different sets of data to produce image products having a more accurate reference system synchronized with map coordinates.

Within three days of the earthquake, CSR scientists registered the initial data sets, combining satellite data with geodetic survey points collected by ground-based GPS readings, and posted the finished products for first responders. The team has worked with Texas Advanced Computing Center (TACC), which manages the backend of the technology, providing storage, high-speed data transfer, and web hosting for CSR’s diverse research projects through their premier data resource, Corral.

“The idea is that you have, effectively, unlimited storage that can be very flexibly allocated and actually can serve multiple purposes at the same time,” says Chris Jordan, the senior operating systems specialist responsible for data infrastructure at TACC. “It’s what Corral is designed to do,”

TACC and the Center for Space Research are also playing a key role assisting the research teams that are investigating the nature of the earthquake, and the likelihood (and possible location) of future seismic activity.

The CSR team has been working closely with Paul Mann from The University of Texas at Austin’s Institute for Geophysics, and Eric Calais from Purdue University’s Department of Earth and Atmospheric Sciences, who have studied the geology and earthquake history of Haiti and the Dominican Republic for decades.

Both researchers are in Haiti to examine the visible evidence of the fault rupture and to determine what risks remain for future earthquakes as stress fields readjust across the region.

Since the researchers’ arrival, CSR has used satellite imagery and low altitude aerial photography to ascertain which of Calais’ sites located on building rooftops survived the earthquake and to provide an accurate image base for Mann’s survey of the rupture.

Preliminary modeling indicates that the fault may still be locked in the Port-au-Prince region, increasing the likelihood of a future quake.

“We’ve got several thousand ground-troops in Haiti and over a million Haitians who have no place to live. Everyone needs to know what the potential is in the immediate future for a quake of the same magnitude, or a quake of lesser magnitude closer to Port-au-Prince,” Wells says.

CSR is also working with NASA’s Jet Propulsion Lab to conduct a series of flights with an interferometric radar system to investigate the entire length of the Enriquillo Fault.

As the Center for Space Research receives new data—from NASA jets creating radar maps of the fault structure to 15 cm. color aerial imagery where you can see individual people—the MAGIC team will continue to prepare those files for use in Haiti, improving the information available to people on the ground.

“These technologies help to preserve the life and property of the citizens in that region,” Wells says. “If you were to attempt this relief effort without any of this information, your horizon of knowledge would be so limited.”

University of Texas news: www.utexas.edu/news/

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