"Eighty five percent of all information is location-based," said Tsering Wangyal Shawa, who is a librarian in title but more like a scout guiding faculty and student researchers through mountains of geographic information system (GIS) data. GIS marries the power of computerized data bases to the versatility of digital graphic displays. Any point, line, or area viewable on the computer screen can be associated with rows of information and other digitally stored information.

Bill Guthe, remote sensing analyst in the University Library's Digital Map and Geospatial Information Center in Guyot Hall. Photo by Frank Wojciechowski

GIS data, particularly from the federal government, have flooded into Princeton, but until the center opened in August 1998 the very quantity of data was an impediment to its use.

"The problem was that we didn't have a person to provide the information to the users," Shawa said. "We can't just collect information, we have to make it available, too."

The center provides access to lodes of geographic and statistical data, plus the tools and guidance to seek correlations in the data, then communicate findings with maps and charts, he added.

While GIS can describe the present and predict the future, it is equally useful for illuminating the past.

Bill Guthe is a GIS and remote sensing analyst for the Educational Technologies Center, which supports faculty in instructional technology and in research. He is analyzing the battlefields of Gettysburg and Wounded Knee for the American Studies course AMS 201: American Places: An Introduction to American Studies.

"At Gettysburg we are trying to give students a sense of the battlefield, so we took aerial photos off the Internet and superimposed them on a model that shows the terrain," he said.

The interactive map of Gettysburg shows the location of troops and the subtle rise and dip of terrain.

"When you follow the path the Confederates had to take during Pickett's Charge you can see just how exposed they were," Guthe said. "There were only a few low rises to protect them. It is frightening to think about."

The three-dimensional display of the killing ground at Wounded Knee is similarly technically engaging and ghastly in what it reveals. The display shows with impressive precision where the Sioux encampment was located, the path of retreat the Sioux took, the disposition of the troops ringing the area, and the strategic location of an artillery battery on high ground.

"It was looking right down on them," Guthe observed.

Shawa and Guthe work together closely to ensure students and faculty receive the maximum benefits from this technology.

Both men said GIS brings a visual power to the presentation of data that is probably as much a bonus as the enhanced ability to explore data. "This integrates the computer-aid ed drawing part of engineering with the landscape analysis part of GIS," said Guthe. "You could do a traffic study of the impact of growth and present it to the public in a way that makes sense. People can share their information so much more easily."

For more information on GIS services at the Educational Technologies Center, contact Guthe by phone at (609) 258-4609 or by e-mail at

wguthe@princeton.edu.

For more information on the Digital Map and Geospatial Information Center, contact Shawa by e-mail at shawatw@princeton.edu or by phone at (609) 258-6804.