Development of a Field Navigation Map and Learning Distance/Bearing Navigation

Introduction
Before the advent of modern geospatial technology, geographers used a wide range of methods to find their path and direction. Some of the earliest methods involved navigation by the stars in the sky(Figure 1.) or by the angle of the sun's rays. In this exercise we used another ancient method to determine angle and distance, pacing.

Figure 1. Example of navigation by stars and lunar position. Image by Tim Woods.

The Romans used a pacing method when marching through uncharted territory. Mile is formed from the root word 'mili' meaning 'thousand.' Mille passuum translated to 'one thousand paces' and was one of the first established units of long distance measurement. (Scotland Mountaineering Council)

From the distance data collected we can create maps that will aid us in Navigation at The Priory in the subsequent exercise.

Methods
For the start of this exercise we needed to measure our own walking pace as measured on a known distance. We determined two points with a 100 meter distance between them and walked using our normal walking pace to the end.(Figure 2.) We repeated the measurement on the way back and compared the results. I found that for every 100 meters I walk about 65 paces. Paces were defined as every time my right foot hit the pavement. In the subsequent navigation exercise I can determine that for every 100 meters I need to travel I will have to walk about 65 paces.

Figure 2. Measurement area for pacing. Just past the grey van is 100 meters.

We will use this measurement on the maps that we created for the subsequent navigation activity at The Priory, a multiple use UWEC facility.(Figure 3.)We constructed two maps to be used, one that utilizes a UTM grid with 50 meter spacing and one that provided Geographic Coordinates in Decimal Degrees.

Figure 3. Locator Map of The Priory in relation to the main UWEC campus.

In order to create our maps we utilized existing aerial satellite images, elevation data, and area boundaries from the general Geospatial Data folder. These features will help us distinguish minor changes in the vegetative cover and topography of the area when we perform the navigation activity. although sometimes helpful, a satellite image is not a good primary tool for navigation because vegetation changes seasonally and it is difficult to discern much detail from an aerial image on the ground. Elevation is a useful feature to some extent as it gives you an idea of what the ground topology should look like. I used a 5 foot elevation spacing because it looked to me to show an adequate amount of feature change while not cluttering up the map. Large changes in ground elevation can be useful for navigation because it gives us features to look for such as slopes or hills, but it can also hinder our navigation as it is difficult to perform standard walking paces up and down the area.

The most important aspect of our maps was projecting the right data and having known measurements and scales from which to begin our pacing. I opened the Layout View in ArcMap. I open up the data frame properties and clicked the grid tab. (Figure 4.)

Figure 4. Grid tab in the Data Frame Properties Window.

This gave me to option to create a new grid. All of the grids were set as Measured Grids because we wanted one that would divide the map into standard measured units. From the windows that result I could adjust the properties such as font, color, significant digits, and appropriate spacing. This also where I set the coordinate system for each map.  This part was the most difficult because it required both playing around with the features and then fine adjustment. I found that subjectivity was also involved. What I found to be a pleasing color and spacing may have seemed aesthetically unpleasing to another. The final step was to adjust the other features on the map such as scale bar, north arrow, title, legend, watermark and helpful data. Being able to compare the final UTM map (Figure 5). and the GCS Decimal Degree map (Figure 6.)will be helpful during the navigation exercise.

Figure 5. Final UTM map created for the navigation activity.
 

 

Figure 6. Final Decimal Degree map created for the navigation activity.

Discussion
Pace counting for distance measurement is a useful tool as it requires no equipment other than one's self. However, ground hazards such as brush, steep elevation changes and impassable areas might be a hindrance that newer technology will be able to overcome. Another issue is that there can be variation in paces for a variety of reasons including fatigue, miscounting, over or undercompensating, and needing to sidestep to avoid hazards. Regardless, I predict that this method will be beneficial to have in my repertoire in case of technology failure.

I am slightly apprehensive using the maps in the field. Although I often use maps for reference I tend to rely on landmarks instead of pacing to achieve distance measurements and orientation. It will be an interesting exercise and I hope to solidify my confidence in using this method. I believe comparing the two maps and using my team's combined skills will help me develop confidence in my own navigation skills.

Conclusion
It is vital to have multiple navigation methods available for use because one never knows what situation they will be presented. Knowing how to create a map for navigation use is also vital because not every area has the correct area or data for your use. It is useful to learn these things and these skills with be utilized in our future careers as geographers.

Sources
The Mountaineering Council of Scotland
The Greatest Idea Campaign Ever Run, Tim Woods
UWEC Resident Halls