There’s an interesting post on slashdot today, on a product that will geo-tag your photos. Geo-tagging a photo means recording some geographic information at the time you take your photo, typically the longitude and latitude.
At first glance I thought it might be another on of these data-loggers, but actually, with a minor addition, it’s a pretty nifty bit of hardware.
GPS is a passively received signal beamed down from several satellites every second. A basic data logger simply records that information and you can then download it to your computer and do something with it later. The idea is, you keep one in your pocket and then you’ve got a record of where you’ve travelled around all day. You could for instance, switch one on, pop it in your pocket, walk around the perimeter of the village that you’re doing work in, and then return to your computer and now you have a perimeter for the area you worked in.
PARADISEC loves this kind of information. Our catalogue includes geographic information for most of the records stored within it, so that people can search on a map for languages. It’s displayed as a density plot so you can see where concentrations of materials occur. Try it out if you like by logging in as a guest, and then do a quick search by location (hint: most of our material is in the pacific region!).
By keeping your camera clock up to date, you can pull an additional trick by lining up your GPS track with the time information stored in your digital photos. This means you can figure out where each photo was taken. The Sony data-logger above includes a clip so you can attach it to your camera, so the location is recorded wherever your camera is. The only problem is that, by recording your location every second, the space in your logger can fill up quite quickly. Its a simple solution that has a few simple short-comings.
The geo-tagger I mentioned above overcomes this by clipping onto the camera flash shoe. Every time you take a photo, the signal sent through the shoe tells the data-logger to record the location then and there. As an added bonus, this unit has a digital compass built in, so you even have the direction included. The time and date are also recorded, which is then presumably used to line up your photos with the log of data (yes, you still have to use a computer program to attach the data to each photo). …I wonder if it can be used to correct the time in your photos too – GPS time is extremely accurate – that would make it triply useful. That would presumably be a feature of whatever 3rd party software you use.
There are cameras out there on the market that have geo-tagging built in, in fact its coming to the fast moving world of mobile phone gimmickry now. There are professional set ups that record not only the location and direction, but also the distance to the object in the center of the screen. Some people have even come up with their own solutions.
Certainly you can easily purchase simple data–loggers, or even build
This is a low tech solution that yields a useful addition of data, that I hope fieldworkers can be encouraged to add. Having to keep the camera clock (very) up to date is a weakness of the system (but great if it encourages people to do it… I’m crazy about metadata!). The extra hassle of assembling the data afterwards is probably going to steer most field-workers away in the short term so I look forward to the future of cameras where these kind of technology simply becomes the default. Its amazing the kinds of information you can infer from spatial-temporal information. In a project I’m working on at the moment, we practically depend on it to auto-magically enrich your fieldwork data, pre-archiving.
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