Mapping.....

....representing 3D elevation terrain data in a human-friendly form.

Here is Google Maps presentation of an area used recently for an O-course. I've asked it to use 3x vertical exaggeration. It amounts to an aerial photograph.

While giving an impression of the area, the vegetation cover obscures the detail it would be good to have.

How do maps differ from photos?

Maps of the area do not necesarily show the features we particularly value, as orienteers. They lose the photo-realism of views like the above, and try to represent the features a human would typically value. But orinteerers are not necessarily typical in their requirements.

Even our O-maps can't make everything crystal-clear. That's one of my excuses for slow performances! I find it particularly hard to tell whether contours are representing rising or falling ground- the streams are not clear enough to show which are ridges & which are valleys. Hilltops & cliffs are the most helpful features here, but are not always present.

The O-Map

We have become used to colour, laser-printed high quality maps. And on the web, with RouteGadget, can even watch our animated route as the young stallions race ahead of us.

Home-brewed visual aids

The Ordnance Survey provides data freely on a 50m grid for elevation, so I thought I'd play with using it in our Quantock Orienteers mapped areas- in this case the recent Floorey Down QOFL. If nothing else, I've gained a better appreciation of the lie of the land in this area, which can't fail to help me when it is next used! It certainly shows how much work our orienteering mappers have to put in to create the detailed maps we have come to expect.

My first orienteering involved black-and-white maps on non-waterproof paper. You hand-copied the map corrrections, course controls, etc.

This page is dedicated to Dave Holmes, orienteer & mapper extraordinaire, and a great friend who we all miss. In our hearts you are running forever, Dave.