Backround: Aerial photography and remote sensing can be used to measure current land cover and recent land use change. However, these technologies are fairly recent and therefore time series are limited when using them. In contrast, historical landscape photos exist for many locations from much further back in time. Repeat-photography studies return to the locations of historical photographs a take identical photographs to examine changes. However, in general, these studies are limited to qualitative measures of change inferred manually because these obliquely taken photographs can't easily be georeferenced.
Question: I'm helping with an repeat-photography study in Alaska, we have historical (up to 100 years old) photos of the landscape (with lat/long) and we'll be retaking photos this year at the same locations. We also have access to a high resolution DEM and aerial imagery. The goal is to quantify forest cover change between the photos. I'm looking for a method to georeference these obliquely taken photographs, drape them over the landscape, and create a map to be compared with aerial photography. Essentially I want to transform an oblique photo to an orthophoto.