Spatial resolution implications of digitizing aerial photography for environmental applications

Accuracy, flexibility and cost effectiveness are advantages of using digitized aerial photographs as a data source for remote sensing studies of the environment, such as forests. However, the relationship between the resolution of digital images and the aerial photographs from which they were derived must be addressed to ensure valid application using the environmental data. This communication considers issues that affect the information content of environmental data through the spatial resolution of photographs and digitized images, and suggests how users can optimize the spatial resolution of the latter by selecting an appropriate scanning aperture. An optimal scanning aperture can be chosen by considering the combination of the resolving power of the camera system, the scale of the original photograph and the desired pixel size of the digital image. Optimizing spatial resolution while scanning will maximize the spatial information obtained from the original photographs without generating unnecessarily large file sizes. The authors make several recommendations for the digitization of aerial photographs for environmental applications, such as analyses of forests.