We live in interesting times, and I don't just mean in the Chinese curse sense of the phrase. I stumbled across this story on the BBC site, which talks about aerial photographs and how they're used.
The Big Picture, With Bells On
If you're a user of Google Maps, then you may already be familiar with Google Maps option to view a standard map, a satellite image of whatever location you're looking for, or a hybrid view which overlays the standard map information (road names and so on) over a satellite image. If you're traveling somewhere new, sometimes looking at images of the terrain you'll be going through can really clarify the directions you're following. I'll give you a for-instance. I recently headed down to western Massachusetts to deliver a vintage sewing machine to a guy who fixes up machines. Armed only with his address and a standard map, I'm not sure I'd have been able to find him. However, the hybrid view of his location told me that his shop was off the road in a cluster of other industrial buildings. I knew to look for a cluster of buildings in order to find him.
In September 2004 we published an article that talked about melding data together with satellite imagery, maps, and other information to create what the author described as "a world in which sensors become pixels and we browse reality as easily as we browse Web pages today." The BBC article I mentioned earlier deals with a company called Pictometry. Pictometry does digital oblique aerial imaging, where images are taken from above, but at an angle. What this means is that towers and other pointy bits on buildings appear tall rather than foreshortened. What you see in the image is a closer match to what you see on the ground.
What's fascinating is how these images can be used. First responders can use them to understand the quickest route to (and around) an accident or emergency. Firemen in snowy areas can figure out where the hydrants lurk, hidden under snow banks. Sewer repair guys can figure out where the problem actually is. The images are linked to geophysical data, so it's not just a picture, it's picture plus position.
The Evolution of Maps
People have been trying to represent their understanding of the world on flat surfaces for centuries. Look here to see some ancient maps, for example. Topographical maps display both the variability of terrain and the routes through it but require some practice to read. Now, with GPS and digital imaging we get things like Google Earth and other approaches. The point of all this is to combine multiple types and sources of data into some useful and unified whole.
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