Pacing for Distance Measurement

compassmap

You are heading towards a control on a compass bearing, but just how will you know when to stop and start scanning for the control flag?  This is where you can use a technique called 'pace counting' or 'pacing' to help you.

Pacing or pace counting is a system for keeping track of distance travelled by foot through terrain.  All of us have a regular pace that we normally walk and by judging how many steps you take per 100 metres, you will be able to get a good estimate on how far you may have travelled.

 

 

Calculating your Pace

To obtain a measure of your pace, find a road, trail, sports field or track that you know to be 100 metres long.  With an accurate length, you are set to begin.  There are two ways to count up your paces – by double pace or single pace.  If counting double paces, you only count when your right foot hits the ground.  So for example, if you take 120 paces per 100 meters, you would count 60 double paces.  Once you got your pace per 100 meters figured out, with some simple math you can calculate other distances. (ie. 60 paces per 50 meters, 30 paces per 25 meters, etc). You can even record this information on a quick reference card if you wish.

Since orienteering is also a running sport, it is useful to also estimate your pace while running, which typically has a tendency to lengthen your stride.  If counting paces in very rough terrain, you will be usually walking.  However, there are times when you can run along a trail or in an area of open forest and also need to keep track of the distance you have travelled. 

Here is a useful video provided by Sport Scotland (Glenmore Lodge), which discusses the technique for calcluating your pace:

 

As discussed in the video, you will probably be able to get your most accurate estimate of distance using pacing when travelling on a relatively smooth surface (such as a trail or roadway) on flat ground. These are your most ideal conditions for pacing, but as we know, orienteering takes us over a variety of terrain therefore it is important to be able to factor in how these terrain changes may affect your distance estimation through pacing. 

The following conditions would have a tendency to shorten your pace:

The following conditions would have a tendency to lengthen your pace:

 

Estimating Distance on a Map

Once you have your pace figured out, your next stage is being able to estimate the actual distance that you need to travel to the control. For this, you need to consult your map.

Experienced orienteers are able to get a good estimate of distance by using the scale of the map to judge the the relative distance between controls. However, if you are new at this skill it is ok to take your time and measure the distance more accurately.

Most baseplate compasses will have a centimeter scale along one edge.  Looking at the example on the right, you can use this compass scale just like a ruler and line it up between the two features on your map for which you wish to check the distance.   

 

According to this example, the distance measured is 4 cm.  Now you will need to do a quick conversion based on the map scale.  If the scale of the map is 1:10 000, this makes things particularly easy as 1 cm = 100 meters.  Therefore, this would mean the distance between Control 9 and 10 would be 400 meters. 

Since most orienteering maps are either 1;5000, 1:7500 or 1:10000,, using a centimeter scale on a compass provides a quick and easy way to check a distance that is in a straight line. For example, if the map scale is 1:5000, this would mean that each 2 cm = 100 meters.  Similarly, if the map scale is 1:7500, each 1.5 cm = 100 meters.   Once you get the hang of this quick calculation, it will only take a few seconds to use the edge of your compass’s centimeter scale to measure the distance and convert it into the meters you will need to travel to reach your control. 

Most experienced orienteers, develop an ‘eye’ for the distance and may be able to estimate it without having to use the compass edge.  However, when you are first starting out, it is a good idea to take your time to be more precise instead of quickly guessing and perhaps making a wrong assumption on the distance you need to follow. In time, you will also be able to estimate distance by 'eye' and won't need to pause to measure it first.

Now, go out and find a 100 meter section, and count up your pace! Have fun.

 

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