Tuesday, 19 April 2016

Brown squiggly lines bring bliss

I know how to use OCAD - orienteering map-making software. I'm not the most proficient nor practised as I don't map very often - and I haven't mapped any seriously tricky terrain. I've modified other people's maps and I've drawn my own maps of schools and a park. I'm busy with my first river map (mapping the bank features and islands) and a map of a primary school here in Parys.

My next project is to create a basic orienteering map for Forest Run. It serves a couple of functions:

  • A hand-out to introduce participants to the delights of a map and knowing where you are. Yes, the route will be fully marked, but I like to think that runners may enjoy knowing where they are. Of course they can tuck it into their backpacks and leave it there...
  • A guide for my marshals (many of whom are orienteers) to get to their marshalling points - and for sweeping the route.
  • For safety: this special version for my marshals and medics will show escape routes and accesses.
  • The start of a wonderful map for technical, long-distance orienteering events and for rogaining, a long-distance, time-limited form of orienteering - my favourite-favourite.
For now, this will be a really simple map - I'm short on time and a complex map is not required just yet.

In order to create an orienteering map, one needs a base map. We generally use orthophotos, which have been corrected for distortion and they carry contour lines, which indicate elevation and topographical features. Google Earth screen shots do work - for small areas - but there are no contours. 

Fortunately, being in the modern age, we can get digital aerial imagery and also digital contour lines; both of which can be georeferenced and imported into OCAD.

I've never had experience with this.

Until today.

OMG! My heart runneth over with bliss. And I can give full credit to Stephanie, who supplied me with the necessary files - all beautifully georeferenced and ready to go. Sarah R and Paul were also on hand, offering assistance - thank you. Nic, with his OCAD experience, got me to the final stage of success tonight - getting my GPS track in.

And so it was that I successfully imported the contour line file. With counsel, I got the background images in (13 x image files at 285MB each!). And I've just experienced the joy that comes with importing a gpx file and successfully positioning it so that my track for the routes is in the correct place. Oh, what joy!

Now the work starts - to turn these squiggly lines into something that can be read and interpreted. 

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