Simplification Techniques

Orienteering in complex terrain can be overwhelming. Here I’ve captured my approach to simplifying some Australian granite terrain.

The Map

Gudgenby Homestead, in the ACT. The course segment is controls S-14 from the M21E course from Day 1 of the 2010 Australian 3-Days. My route is also drawn.

Gudgenby Homestead
Gudgenby Homestead

Simplified Overlay

Gudgenby Simplified
Gudgenby simplified

I have drawn a simplified map showing the most important features I used in each leg. I also indicate my “orienteering speed” in green (fastest), orange (navigating), and red (I think I just have or am just about to make a mistake). Orienteering speed is roughly comparable to running speed, but things like hills, vegetation (and fitness 🙂 get in the way. I have added comments which are partly planning and partly what eventuated.

The features I have drawn are:

  • contours (gullies, spurs and hillsides),
  • rocks (rocky areas or individual distinctive rocks),
  • obvious linear features (tracks, fences, powerlines, creeks) and
  • vegetation (trees in the open or thicker stuff in the trees).

I made use of more features (and the control descriptions) inside the control circle to ensure I went to the right spot (eg, #12 I crossed the bare rock to drop into the two boulders) but showing all these features would defeat the purpose of the simplification exercise.

Types of Simplification

Gudgenby features
Gudgenby features

Now, a slight variant of the simplified map, which classes each feature as one of the following:

  • HR = Hand Rail, a linear feature to guide you to your destination
  • WP = Way Point, a point feature to note as you run
  • AP = Attack Point, an obvious feature used to “attack” the control
  • OS = Obvious Site, a control site sufficiently obvious that an attack point is not needed
  • CF = Catching Feature, (usually linear) tells you that you have gone too far
  • stuff = none of the above, general features used for navigation

My orienteering was a lot faster when I had good handrails to make the navigation easier. Obvious catching features are good to use but don’t worry too much about looking for catching features (retro-active) if you make use of all the pro-active features. The benefit of way points and attack points is that if you get lost later, you can say confidently “I knew where I was at that point”, and work out what you might have done wrong since then, cutting down the number of possibilities you have to consider.

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