BARRIER-ISLAND VEGETATION MAPPING USING DIGITIZED AERIAL-PHOTOGRAPHY

A vegetation map of the Assateague Island National Seashore of Maryland has been constructed from computer analysis of three-band digitized color IR photographs using the ORSER digital data processing system. Because the raw data were not calibrated and corrected for density variation across the photographs, a large number of spectral signatures had to be developed for each vegetation class. Classification accuracy was measured against existing vegetation maps of small sections of the island and against a sample of points ocularly interpreted on the photograph. Area estimates were adjusted for the difference between photointerpreted and computer-generated vegetation types. A high degree of classification success was achieved for the photograph on which signature development had occurred, and moderate success on other frames.