VDI 3793 Blatt 2:1993-10 (R2015)

Aerial images have proven valuable regarding the status documentation of forests and vegetation stands and the monitoring of status changes. For the evaluation of aerial images, interpretation keys are applied. A consistent terminology and the same structure of these interpretation keys for the entire range of applications ensure that the results of temporally or spatially different inventories based on aerial images are comparable. It is only on this condition that aerial photographs can be used to document regional, federal and national comparisons as well as the various stages of long-term monitoring. The interpretation keys described in the Standard have been established for the evaluation of the state of crowns of individual trees. They are applied for the evaluation of analogous aerial images (in Germany found in archives) and for the assessment of crown conditions with digital images.