Clinton, P.J., D.R. Young, B.D. Robbins, and D.T. Specht. 2000. Issues in digital image processing of aerial photography for mapping submersed aquatic vegetation. Pages 292-298, Vol. 2, in Proceedings Sixth International Conference on Remote Sensing for the Marine and Coastal Environments, Charleston, South Carolina, May 2000, Veridian ERIM International, Ann Arbor.
This paper discusses the numerous issues that needed to be addressed when developing a methodology for mapping Submersed Aquatic Vegetation (SAV) from digital aerial photography. Specifically, we discuss 1) choice of film; 2) consideration of tide and weather constraints; 3) in-situ survey and geopositioning; 4) orthorectification; and 5) the analog nature of aerial photography versus electronically-sensed spectral reflectance data in the development of classification algorithms. We digitally classified SAV distributions from both large and small format Color Infrared film imagery acquired coincident to extreme low tides using photographic band ratio algorithms and vector masking. Desktop geographical image processing software was used for image classification and georeferencing scanned, low cost, small format imagery to digitally orthorectified, large format imagery.