On Friday, I went along to a talk on "Great War aerial photography: a source for battlefield survey and archaeology?", given by Birger Stichelbaut of Ghent University in Belgium. This brings the total number of in-any-way-related-to-early-20th-century-aviation talks given at the University of Melbourne during my PhD candidacy (as far as I know and excluding a couple I've given) to one (1). And even this was archaeological and not historical; but it kept me awake even at the quite indecent hour of 10am, so you know it must have been good!
The basic idea is to use aerial photographs of the Western Front trench system, taken over Flanders during the war itself, to help plan battlefield excavations. The main value of this is that they are more useful than contemporary trench maps, which didn't always show every feature and also aren't as accurate when it comes to pinpointing the location of features (to within ~30m, compared with ~10m for aerial photographs). And all sorts of things show up: the different kinds of trenches, gun emplacements, pillboxes, and so on (as well as many remnants from much longer ago). Of course, it's not quite as simple as poring over a bunch of old photos: the full panoply of GIS techniques (photo stitching, orthorectification, georeferencing, DEM overlays, stereo pairs) are used to make sense of them and match them up to present-day photographs and other data. Most of the trenches are no longer extant, apparently, at least in Belgium, so this sort of thing would be of great benefit to projects like Plugstreet. The same techniques could also be used in other theatres and wars where trenches and aerial photographs coexist, though its utility also depends on the soil type and other factors (Gallipoli was deemed unlikely to be suitable, though I didn't catch the reason). One interesting point: magnetic aerial surveys don't help with determining where trenches are, because of the sheer mass of metal lying all over the battlefield.
Of course, I was mostly there to gawk at the stunning photos (the one above, from Rosebud's WWI and Early Aviation Image Archive, really doesn't do them justice. That's an FE.8, incidentally). At the start of the war, they were taken on an amateur basis, with a camera stuck over the side of the aeroplane; by the end, specialised cameras with long focal lengths had been developed, so that photographs could be taken from altitudes safe from anti-aircraft and ground fire. Stichelbaut has many thousands of these images, gathered from various archives around the world. Interestingly (and unfortunately) most of his German photos were found in the archives of the former Bavarian army, since those taken by virtually all the other German armies were destroyed in the Second World War. He showed a map of the European distribution of where the German photos were taken; all fronts were covered to some degree, but the vast majority were in the northern part of the Western Front (i.e., where the Bavarian army was). There were some which rather oddly appeared to be of somewhere in the south of France, hundreds of miles from the front, but these hadn't been checked yet and were probably due to the French habit of reusing the names of their villages!
I would have liked more details about how all this work has actually been used. One interesting snippet was the difference between German cemeteries and Allied ones. From 1915 the Germans constructed elaborate cemeteries for their war dead, not far from the front lines (close enough to turn up in photoreconaissance, at least). These show up very clearly in the photos, and there are no equivalents on the Allied side of the lines. But after the war, the German cemeteries were torn down, while the victorious Allies created their own funereal landscapes, which are so characteristic of that part of the world. Another snippet was the location of a Zeppelin shed near Ghent, I think Gontrode. Stichelbaut's departmental host is actually from that village, and so now he knows why his grandparents' windmill was knocked down by the Germans so the foundations could be used for an anti-aircraft emplacement! Although this was fortuitous, as one of the audience remarked it shows that there's an opportunity to integrate the archaeology with social and local histories. But these were the only hints of applications of the project beyond its uses for trench (re)digging.
Something I should have asked was, is the data going to made available to the public in any way? There are obvious possibilities for Google Earth layers and the like. Of course, I don't know who funded the work and there may well be copyright issues involved too. I assumed that such a technologically sophisticated project would have an equally sophisticated website, but I can't find one at all, beyond a brief mention -- at least not in English. But if you've got access to Antiquity, you can read Stichelbaut's paper describing the project.