Understanding the Battle of Gettysburg Using GIS
Dr. Anne Knowles of Middlebury College answers the question "What could Lee see at Gettysburg?" Dr. Knowles builds two digital terrain models of the battlefield, one from 1996 data derived from aerial photographs, the other based on contour lines extracted from an 1874 map of the battlefield. Using a technique called viewshed analysis, she investigates how lines of sight and real-time geographic information may have influenced commanders' decisions and terrain perceptions. The results suggest that historical maps and evidence from the physical landscape can shed new light on even the most familiar historical subjects.