This is the New Forest in southern England, after being covered by one mapping party per weekend for most of 2006. (slight exageration, but lots of people have visited this area to do mapping)
One thing to notice, is that in the city you have a frame of reference (the street layout) in which you can place things that you see. So even though you might never visit a particular feature, you can see where it is based on what roads are around it.
It's very difficult to do that for features out in farmland or open country. Even if you can see something (say, a copse) you can't put it on the map without knowing its exact position. Which means estimating distance and direction.
That's why countryside maps have the footpaths themselves, but never anything off the path. How would you know where to put it?
To solve this problem, we need a way that you can look out over a landscape, sketch (or photograph) important features that you can see, and then create an accurate map from that information. So what frameworks are available to help with this estimation?
Contours would be a start. Very few OSM map tools allow you to view the contours of an area when you're editing. But if they did... you'd be able to match your photos against the landscape, and place features in their correct places relative to hills and valleys.
Anyone want to put the technology together, so that we could test it with a snowdonia mapping party?
1 comment:
Interesting post ojw, and actually along the lines of what I was thinking while out this afternoon... erm... mapping some more of the New Forest. :-)
We have potlatch almost out now, maybe I could work on modifying that given it can already talk to Yahoo. Yahoo maps of the countryside can just about be used to estimate field boundaries. Maybe it could have the option of displaying contours and NPE maps - the latter could probably be used to estimate crags and the like.
Nick W
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