Monoplotting

Monoplotting is the process of creating and/or editing a segment or point map while a scanned photogrammetric aerial photograph is displayed as a background in a map window. On the photograph, you should be able to distinguish 2, 3, or 4 fiducial marks and you should know the camera's principal distance. Furthermore, a Digital Terrain Model (DTM) of the area should be available.

By creating a georeference orthophoto (differential rectification) for the photograph, you will obtain a georeference with corrections for tilt and relief displacement and you can, by using the mouse, directly digitize elements of interest on the scanned aerial photograph. See also How to monoplot.