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Aerial Images from Around the World – Andreas Buchholz, GIS and Research Curator for the
National Collection of Aerial Photography (http://aerial.rcahms.gov.uk)
This is probably one of the most important collections of aerial photographs in the world. 1938-1980s
declassified ministry of Defence images. We
have lots of supporting and related information about these images which gives us an increadibly
specific level of detail in the metadata – so we can see when the image was taken – time,
date, year. And
the clock in the image confirms this! Aerial photography connects both little stories but
also big historic stories. It can prove or disprove history. We have imagery of the D-Day
landings for instance. And it’s not just about linking metadata to
these photographs but also it’s about the level of detail of these photographs. All
of us will remember 35mm film but we have collections with even larger levels of detail.
You can see a man in a field say – it’s Google Earth but 60 years ago.
We have the resolution and also the resolution of time. We cover the same areas at different
times. So our hay field has a tower block and major road in place by the 80s. This is
fascinating and also very useful and important for private researchers. We can look at bomb
damage between 1943 and 1945. That was the light part of the talk but now
I want to talk about why I want to be here, to improve the searching and mapping around
these images. We have 15 million images, not all of them catalogued. We have an ACIU
Archive GIS – Coverage map – you select an area of the map using just an ARC GIS Viewer.
One area will have lots of attached images. These come from maps we have scanned – it’s
a time consuming search for reference numbers, then you can compare that to the images. We
would like to do something nicer. We have about 60,000 aerial images which cover
various countries, you can select a broad region, and you get a large number of results
– and you can view those on Google Earth to help get you to more detailed results.
You can see one plane took over 700 images. We give a rough indication of coverage – not
all cameras show the same level of detail – and from this view you can click back
to view the specific image you
want to see. If an RCAHMS subscriber you can then zoom in further and further for more
detail. One of our key users of the archive is a German bomb disposal company
– about 10% of all bombs dropped didn’t explode so there is a real issue with unexploded
ordnance that still needs to be dealt with – especially when major building work is
being undertaken. At the start of the presentation I tried to
convince you of why I was
so passionate about these images. Here is another
All images were taken with a 60% overlay that means you have stereo. That’s not just very
useful for accuracy, for perspectives. But you can also gain 3D views of materials.
We are also using OpenStreetMap to compare modern features, or view the images as layers.
Addy) There is a Dutch website which uses a rectangle for all
the maps of Holland – it’s not great
at the top level but you can browse thumbnails of maps as you zoom in.
We have been experimenting with sliders etc. but haven’t found a set up that works as
we need yet.