Robert D. Leighty, 75, a research scientist who helped pioneer numerous aerial photo interpretation techniques that the military still uses, died June 10 of melanoma at his home in Vienna.

Working under a professor at Purdue University in the late 1950s, Dr. Leighty developed methods of extracting important terrain features from aerial photography. These techniques also had civilian applications in such areas as site selection for roads, airfields and dams.

Years later, his expertise in mapping terrain and extracting information from maps -- first manually and then with computers -- led to his involvement in the Army's pioneering efforts in artificial intelligence. The application that most intrigued him involved developing an autonomous vehicle, a robot that drove itself.

Dr. Leighty was born in Johnstown, Pa., and graduated in 1952 with a civil engineering degree from the Virginia Military Institute. He was immediately commissioned into the Army and served in Korea from 1952 to 1954. He was awarded a Bronze Star for his duties as chief of the intelligence branch of the Engineer Section, where he organized and operated a flood prediction program for Army units in the field.

He received a master's degree in civil engineering from Purdue in 1956 and a doctorate in electrical engineering from Ohio State University in 1973.

In the early 1960s, he joined the Air Photo Research Branch of the U.S. Army Snow, Ice and Permafrost Research Establishment in Chicago, where he applied newly developed interpretation techniques to photo and infrared aerial imagery in arctic and subarctic regions. When the branch was transferred to the Cold Regions Research and Engineering Laboratory in Hanover, N.H., he became assistant chief of the lab, renamed the Photo Interpretation Research Division. He also performed several classified terrain analyses in support of the Vietnam War and activities in Thailand.

In 1970, his division moved to Fort Belvoir and became part of the U.S. Army Engineer Topographic Laboratory, where his research resulted in one of the first mathematical approaches to describing and organizing terrain. The pattern recognition techniques he helped develop allowed topographers to move from grease-pencil drawings of topographical features to computerized imaging.

In 1973, he became chief of the Center for Coherent Optics at the Engineer Topographic Laboratory's Research Institute, where he co-patented a hybrid optical-digital system that is still in use. After becoming chief of the Center for Artificial Intelligence at the institute, he directed research in image understanding, computer-assisted image analysis and terrain databases.

In 1983, he was named director of the Research Institute. One of the institute's primary projects during his tenure involved developing a vehicle that uses machine vision to plan its route, avoid obstacles and maneuver to a goal. Unlike, for example, a Martian land rover, which has a "driver" back at NASA, the Autonomous Land Vehicle essentially drives itself.

Dr. Leighty retired in 1986 and in 1992 was inducted into the U.S. Army Topographic Engineering Center's Gallery of Distinguished Civilian Employees. In retirement, he established Leighty and Associates Inc., a company that assisted government and corporate clients in developing research programs and assessing emerging technologies.

A former offensive guard on the VMI varsity football team, Dr. Leighty loved sports and was a Washington Redskins fan. He also was a volunteer judge for the Northern Virginia Regional Science and Engineering Fair for Arlington Public Schools.

Survivors include his wife of 52 years, Martha Ann Leighty of Vienna; three sons, Brian D. Leighty of Ponte Vedra Beach, Fla., Brett A. Leighty of Fairfax City and Robert S. Leighty of Phoenix; and seven grandchildren.

Robert D. Leighty also worked on artificial intelligence.